Sekhar Babu

Sql Server - Fix Error - Can not use the backup file because it was originally formatted with 512 and is now on a device with sector size 4096

2017-11-12T01:03:00.000+05:30

Recently i encountered Sql Server Error when i try to take backup of database from SSMS (Sql Server Management Studio) i.e

System.Data.SqlClient.SqlError : can not use the backup file "path" because it was originally formatted with sector size 512 and is now on a device with sector size 4096

Solution:

Problem is , backup file which was created with different sector size , so it is not possible now to use it. So solution is remove that backup file

Now add the new file for taking backup and ok

That's it simple. Just remove the old backup file with different sector size.

[Solved] C# - OriginalValues cannot be used for entities in the Added state Visual Studio Error

2017-10-27T05:37:00.000+05:30

Hi, recently i encountered runtime error when i try to insert values using Entity Framework

"OriginalValues cannot be used for entities in the Added state"

This could arise because missing column or inserting null value or column width exceeding in insert statement.

You can find the error message in Exception object

$exception.EntityValidationErrors[n].ValidationErrors[n].ErrorMessage
$exception.EntityValidationErrors[n].ValidationErrors[n].PropertyName

Based on your Error Message you can take corrective action to rectify this.

Thanks.

[SOLVED] access denied can not execute the program csc.exe after publishing .net application web deploy mvc app

2017-09-29T08:56:00.000+05:30

Hi, Recently i encountered this error after publishing an application to winhost server.

Error stacktrace is

[Win32Exception (0x80004005): Access is denied]

[ExternalException (0x80004005): Cannot execute a program. The command being

executed was "E:\web\nrgwareh\bin\roslyn\csc.exe"

It is an mvc application using visual studio 2017 , targeted framework is 4.6.2.

I just published using webdeploy method. it is successfully deployed but when i try to run i encountered this one like

when i run locally its working fine. But here problem is winhost doesn't allow csc.exe to run which is roslyn compilation.

When we create a web application either webforms or mvc using .net framework 4.5 > then project is pre installed with roslyn csc.exe compilation. although it was successfully published to hosting environment, but some servers doesn't allow to run that roslyn compiler.

Solution 1:

Here solution is just compile and deploy project without any roslyn or any csc.exe files.

just go to Nuget manager, find the package Microsoft.CodeDom.Provider.DotnetCompilerPlatform , uninstall it.

Now rebuild and re publish, then this problem gone away.

Solution 2:

In some hosting environments we have option to allow or run csc.exe files, just change that setting or allow read/write to exe files, it get's fixed.

Hope it can be useful to some folks.

[Solved] Extender Provider failed to return an Extender for this project - Visual Studio Community 2015

2017-09-05T12:33:00.002+05:30

Hi.., Recently i encountered visual studio designer exception when i try to open EDM file in visual studio " Extender Provider failed to return an Extender for this project " like this below

Problem is i have been running the application 5 hours plus time, without stopping in local.

Then when i try to view edmx file, encounter this exception.

To stop this exception just reload the project so that all objects gets created again and available to view.

When an application is running idle for hours, it is better to reload that project.

You don't have to delete obj and bin folders. But for different situations it may work. Possibly when this exception encountered while in working in designer mode by simply reloading project, you can remove that exception.

[Solved] : failed to create component 'Report Viewer' System.runtime.interopservices.COMException(0x8004D745)

2017-02-18T11:46:00.000+05:30

Hi there. Recently i encountered this error when i migrated visual studio 2008 windows application to vs 2012 . Here i am dragging report viewer to control on windows form, then i encountered a long list of error message

Problem is project reference is enabled for version 10.0.0 for report viewer but toolbox is adding 11.0.0.0 version.

Solution: just add the System.ReportViewer.Winforms 11.0.0.0 version remove 10.0.0.0 version.

You will get these kind of designer errors when you migrate to higher version. Just check the references added to project properly.

Hope it helps you.

Data Binding with WPF : Binding to XML

2013-08-21T15:15:00.000+05:30

Introduction:

In this article i will explain How to bind XML Data to Application UI in WPF. What are the different ways to specify the XML Data to Applicaiton, How to bind the xml elements to UI in wpf etc.

Download SourceCode and Video Explaining How to bind Xml Data to ListBox in WPF

Description:

In wpf for accessing xml data in your application you can use XmlDataProvider Class. This class provides declarative access to xml data for binding. XmlDataProvider Class provides three ways to access XML Data.

You can embed inline XML Data within the tag inside XmlDataProvider Class.
You can use Source to specify the Uri of the XML file.
You can use Document property to specify the XmlDocument as binding source.

One Important property of XmlDataProvider Class is XPath which defines the level binding source in XML file.

Embedding Inline XML Data:

</x:XData>
        </XmlDataProvider>

</Window.Resources>
    <grid>
     
        <listbox  x:Name="ListAuthors" Grid.Row="1"  ItemsSource="{Binding Source={StaticResource AuthorNames}, XPath=*}"  >
            <ListBox.ItemTemplate>
                <datatemplate>
                   
                        <grid>
                            <Grid.ColumnDefinitions>
                                <columndefinition Width="100"/>
                                <ColumnDefinition/>
                            </Grid.ColumnDefinitions>
                        <textblock Grid.Column="0" Foreground="Red"  Text="{Binding XPath=@name}"/>
                        <textblock Foreground="Blue" Text="{Binding XPath=@age}" Grid.Column="1"/>
                      
                        </Grid>
                   
                </DataTemplate>
            </ListBox.ItemTemplate>
        </ListBox>
        
    </Grid>
</Window>

If you see the XAML code XML Data is embed with in tag. This XML file has root element as Authors and child element Author with two attributes name and age.

So for accessing these XML element in ListBox, i specified the itemsource to AuthorNames, XPath=* means it will returns all the data in XML. We can use XPath to query against the XML data

XPath=*[@age>25] will returns the Authors whose age is greater than 25. In this way query against Data.

Accessing XML Data By Setting Source:

I Have an XML File as Follows:

<?xml version="1.0" encoding="utf-8" ?>

</Mobile>
    <mobile Brand="Nokia">
      <model>N147</Model>
      <stock>10</Stock>
      <price>13000</Price>

</Mobile>
    <mobile Brand="Samsung">
      <model>N197</Model>
      <stock>100</Stock>
      <price>31000</Price>

</Mobile>
    <mobile Brand="Samsung">
      <model>N127</Model>
      <stock>100</Stock>
      <price>31000</Price>

</Mobile>
    <mobile Brand="Samsung">
      <model>N1937</Model>
      <stock>100</Stock>
      <price>31000</Price>

</Mobile>
    <mobile Brand="Samsung">
      <model>N1957</Model>
      <stock>100</Stock>
      <price>31000</Price>

</Mobile>
  </Mobiles>
  <cds>
    <cd Brand="Panasonic">
      <model>121</Model>
      <stock>300</Stock>
      <price>20</Price>
    </CD>
    <cd Brand="Panasonic">
      <model>121</Model>
      <stock>300</Stock>
      <price>20</Price>
    </CD>
    <cd Brand="Zoom">
      <model>111</Model>
      <stock>300</Stock>
      <price>20</Price>
    </CD>
    <cd Brand="Zoom">
      <model>101</Model>
      <stock>300</Stock>
      <price>20</Price>
    </CD>    
  </CDs>
</Stock>

I am displaying these data in UI as follows

Here is the XAML Code:

<window x:Class="XMLData.Window1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="Window1" Height="300" Width="453"> <Window.Resources> <xmldataprovider x:Key="Data" Source="/XMLFile1.xml" /> </Window.Resources> <grid> <combobox Height="23" ItemsSource="{Binding Source={StaticResource Data}, XPath=/Stock/* }" HorizontalAlignment="Left" Margin="18,14,0,0" x:Name="comboBox1" VerticalAlignment="Top" Width="120" > <ComboBox.ItemTemplate> <datatemplate> <textblock Text="{Binding Name}"/> </DataTemplate> </ComboBox.ItemTemplate> </ComboBox> <stackpanel Orientation="Horizontal" DataContext="{Binding ElementName=comboBox1,Path=SelectedItem}"> <listbox Height="100" ItemsSource="{Binding Path=ChildNodes}" HorizontalAlignment="Left" Margin="16,53,0,0" Name="listBox1" VerticalAlignment="Top" Width="120"> <ListBox.ItemTemplate> <datatemplate> <textblock Text="{Binding XPath=Model}" /> </DataTemplate> </ListBox.ItemTemplate> </ListBox> <stackpanel Margin="16,0,0,0" DataContext="{Binding ElementName=listBox1, Path=SelectedItem}" Width="191" Height="71"> <textblock Text="Brand: "></TextBlock> <textblock Grid.Column="1" Text="{Binding XPath=@Brand}"></TextBlock> <textblock Grid.Row="1" Text="Stock: "></TextBlock> <textbox Grid.Row="1" Grid.Column="1" Text="{Binding XPath=Stock}" /> </StackPanel> </StackPanel> </Grid> </Window>

In this example i am loading main root elements i combobox, based on the combobox selection ListView is loaded with the Model, Based on the selection in ListView then Brand Price details will be shown.

Watch this Video explaining How to Bind Xml Data to ListBox in WPF

Download SourceCode for More Clarification.

Conclusion:

I hope you got some basic details about accessing xml data in wpf and bind it to UI.

Don't forget to Comment and share it for our friends if you like this post. Thank You.

Data Binding in WPF with Example

2013-08-15T19:21:00.000+05:30

Introduction:

In this article i will explain

What is data binding in wpf,
What are the key components of binding,
How to bind an element as data source,
How to bind a Property as Source,
Binding an object as DataContext,
Different Binding Modes in WPF etc.

Download SourceCode And Video Explaining Binding in WPF

Description:

In the previous article i explained what is wpf and wpf basics, wpf architecture, Windows Forms Vs WPF, what is xaml and xaml file compilation process, Baisc Drawings and Shapes in wpf etc.

Data Binding in WPF:

One of the WPF Powerful feature is it's Data Binding Concept. It is the process establishing connection between Application User Interface and Business Logic. It requires a Binding Source and Target .

Establishing Binding in WPF

Source provides the data, and Target displays the data. Data Binding Connects UI to Data. When Source Data values changed then UI is updated. This Updation depends upon the Different types of Data Binding Modes. These Data Binding Decreases the code when compare to general binding. It also enables Template Binding means we customize the data more precisely by specifying which property to bind to which control.

So a Binding Consists of 4 major Components:

Source

Source Path

Target Depenedency Object.

Target Dependency Property.

Here Target can be any Element or any accessible property that is derived from Dependency Object for example TextBox controls Text Property is an Dependency Property. If you see the object hierarchy in wpf almost all controls are derived from Dependency Object. When coming to Source, it can be any public property, CLR object, Ado.Net DataSet, XMLDataProvider, ObjectDataProvider etc.

Binding a TextBox Text Property to a TextBlock Text Property

If you see the above image it gives you clear picture about data binding in wpf. Here Source is a TextBox, Text property of this textbox is bind to TextBlock Text Property. You can see the Code and output below.

Element as Binding Source Example:

Output is

WPF Simple binding

In the above example if you type any text in textbox then immeadiatly it is displayed in TextBlock. Upto now we saw How to bind an element to another element, Now Let's see how to bind properties to XAML elements.

Now add a class to your project and name that as MobileShop which consists of three properties ShopOwner, Shop Number, and Address as below

Now add a new window to your project and drag three textboxes ,three labels for displaying above three properties. XAML code looks like below.

<grid>
        <label Content="Shop Owner : " Height="28" HorizontalAlignment="Left" Margin="12,51,0,0" Name="label1" VerticalAlignment="Top" Width="87" />
        <label Content="Mobile Shop" Height="38" HorizontalAlignment="Left" Margin="68,0,0,0" Name="label2" VerticalAlignment="Top" Width="130" FontSize="20" FontWeight="Bold" />
        <label Content="Shop Number : " Height="28" HorizontalAlignment="Left" Margin="12,85,0,0" Name="label3" VerticalAlignment="Top" Width="96" />
        <label Content="Shop Address:" Height="28" HorizontalAlignment="Left" Margin="12,119,0,0" Name="label4" VerticalAlignment="Top" Width="88" />
// Binding ShopOwner Property
        <textbox Height="23" Text="{Binding Path=ShopOwner}" HorizontalAlignment="Left" Margin="118,56,0,0" Name="textBox1" VerticalAlignment="Top" Width="120" />

// Binding ShopNumber Property 
       <textbox Height="23" Text="{Binding Path=ShopNumber}" HorizontalAlignment="Left" Margin="118,87,0,0" Name="textBox2" VerticalAlignment="Top" Width="120" />

// Binding Address Property
        <textbox Height="23" Text="{Binding Path=Address}" HorizontalAlignment="Left" Margin="118,119,0,0" Name="textBox3" VerticalAlignment="Top" Width="120" />
    </Grid>

Now in the Constructor of the Window write below code

As you may see that we have created an instance of class MobileShop and assigned the data for properties.
After that we assigned the object to DataContext Property of the Window. Here DataContext will hold the Data. This property exist for almost all controls that derived from Dependency Object i.e Panel Controls like Grid, Canvas, StackPanel, Wrappanel, Content Controls like Label, Button etc. If we set our object as DataContext to a higher level control then all child controls can inherit that object. Read More About DataContext in WPF.

So now in our present example we set object as DataContext for window parent control so all the child controls have default data source, so we don't need to set Source we just need to mention the Path to which it binds. So in our example we only mentioned Path as below.

The same example can also be done without writing single peace of line code in code behind file, by writing only XAML code as below

<window x:Class="WpfApplication1.Window1"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
       
        xmlns:local="clr-namespace:WpfApplication1"
        Title="Window1" Height="300" Width="300">
    <Window.DataContext>
// We are setting Data Context Here
        <local:MobileShop x:Name="MobileShopData" ShopOwner="Sekhar Babu" ShopNumber="290" Address="Hyderabad" />
    </Window.DataContext>
        
    
    <grid>
        <label Content="Shop Owner : " Height="28" HorizontalAlignment="Left" Margin="12,51,0,0" Name="label1" VerticalAlignment="Top" Width="87" />
        <label Content="Mobile Shop" Height="38" HorizontalAlignment="Left" Margin="68,0,0,0" Name="label2" VerticalAlignment="Top" Width="130" FontSize="20" FontWeight="Bold" />
        <label Content="Shop Number : " Height="28" HorizontalAlignment="Left" Margin="12,85,0,0" Name="label3" VerticalAlignment="Top" Width="96" />
        <label Content="Shop Address:" Height="28" HorizontalAlignment="Left" Margin="12,119,0,0" Name="label4" VerticalAlignment="Top" Width="88" />
        <textbox Height="23" Text="{Binding Path=ShopOwner}" HorizontalAlignment="Left" Margin="118,56,0,0" Name="textBox1" VerticalAlignment="Top" Width="120" />
        <textbox Height="23" Text="{Binding Path=ShopNumber}" HorizontalAlignment="Left" Margin="118,87,0,0" Name="textBox2" VerticalAlignment="Top" Width="120" />
        <textbox Height="23" Text="{Binding Path=Address}" HorizontalAlignment="Left" Margin="118,119,0,0" Name="textBox3" VerticalAlignment="Top" Width="120" />
    </Grid>
</Window>

Here first we have to set the namespace reference to access class files in the same project. i.e

xmlns:local="clr-namespace:WpfApplication1"

Now we can access all contents in the project using local reference like below.

Binding in Code behind file:

We can also perform data binding in code file.

Create the Binding Object

Set the Binding Source

Set the path

Bind the object to Target using SetBinding Method.

Here is an example on how to perform binding in code behind file.

Binding Modes in WPF:

Mode is the one property of the binding element which determines the flow of data between binding source and target. Four Binding Modes available.

OneWay.
OneTime.
OneWayToSource.
TwoWay.

OneWay: If Mode is OneWay means Data flows from source to target whenever source is changed.

OneWay Binding Mode

Here Target UI will be updated only if the source changed. Use this to display read only data in the UI.

OneTime: If the Mode is OneTime then data flows from source to target when application starts or datacontext changes.

OneTime Binding Mode

You can use this to show read only data. This can be used to compare the changes occurred in UI. This Mode very useful source doesn't implement INotifyPropertyChanged Interface.

OneWayToSource: This is completely opposite to OneWay mode. In this Mode if target UI value is changed by user then it is updated in the source if the source is dependency property or it is implemented by INotifyPropertyChanged Interface.

OneWayToSource Binding Mode

In this case target is not updated if source is updated because of changes occurred in target.

TwoWay: If the Mode is TwoWay then Whenever the Source is updated then target is updated, in the same manner if the target value is changed by user then Source is updated with target value and If the binding Source is bind to multiple targets then all the targets are updated with Source data.

TwoWay Binding Mode

Use this Mode when User can change binding source and all it's targets.
For Understanding Binding Modes briefly read this Binding Modes in WPF with example

We have seen Binding Source is updated in OneWayToSource and TwoWay Binding Modes. More Precisely we can control the binding source updation by using UpdateSourceTrigger.

UpdateSourceTrigger in WPF:

UpdateSourceTrigger is one of the property of Binding class. This Property defines the timing of binding source updation. This Property has three Options available. These are LostFocus, PropertyChanged, Explicit.

Suppose you bind a property to a textbox, then if UpdateSourceTrigger is set to LostFocus then all the changes occurred in the textbox is updated in the source when TextBox Lost focus. If UpdateSourceTrigger is set to PropertyChanged then binding source is updated for every change in target. and if the UpdateSourceTrigger is Explicit then binding source is updated only when we explicitly called UpdateSource ( ) method.

For More Explanation about UpdateSourceTrigger Read this UpdateSourceTrigger in WPF Tutorial.

Watch the Video Explaining Binding in WPF

Conclusion:

I hope now you will able to work with wpf bindings. Download the Source Code and watch the Video about Bindings in WPF. Let me know if you need any clarification.

Don't forget to Comment and share for our friends if you like this post.

INotifyPropertyChanged Interface in WPF with Example

2013-08-14T19:36:00.001+05:30

Introduction:

In this article i will explain how to Create INotifyPropertyChanged Interface in Class file, How to Implement it for Binding in wpf.

Download SourceCode

Description:

INotifyPropertyChanged Interface defined in System.ComponentModel Class. It has an event Handler called PropertyChangedEventHandler which can be used to create an Event that can be used to notify the changes occured in Properties.

For example i had a class called MobileStore with Four Properties i.e Brand, Mode, Stock, Price. We can implement INotifyPropertyChanged interface for that class as follows.

class MobileStore:INotifyPropertyChanged
    {
        public string _Brand;
        public string _Model;
        public int _Stock;
        public double _Price;

public string Brand
        {
            get { return _Brand; }
            set { 
                _Brand = value; 
                OnPropertyChanged("Brand");
            } 
        }
        public string Model 
        {
            get { return _Model; } 
            set { 
                _Model = value; 
                OnPropertyChanged("Model"); 
            } 
        }
        public int Stock 
        { 
            get { return _Stock; } 
            set { 
                _Stock = value; 
                OnPropertyChanged("Stock"); 
            } 
        }
        public double Price 
        { 
            get { return _Price; } 
            set { 
                _Price = value; 
                OnPropertyChanged("Price"); 
            } 
        }

public event PropertyChangedEventHandler PropertyChanged;
        public void OnPropertyChanged(string Property)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(Property));
            }
        }
    }

Using INotifyPropertyChanged in Binding :

In WPF Binding Target must be Dependency Property and Source can be Dependency Property or an CLR object or other. Here Dependency Property has built-in Notification feature. So if the Source is an CLR Object or other then we need take care about changes notification to target. In that case we have to use INotifyPropertyChanged Interface to notify the bindings that source property is changed you need to update the UI with new data.

Here is an Example using Above MobileShop class and its properties. The four Properties of MobileShop class are bind to textboxes.

XAML Code:

Conclusion:

I hope you got simple knowledge about How to implement INotifyPropertyChanged Interface for a Class and How to use it wpf binding.

Don't forget to Comment and Share if you like this post for our friends. Thank You.

DataContext in WPF with Example

2013-08-14T17:12:00.000+05:30

Introduction:

In this article i will explain

What is DataContext in WPF? and How to Bind Objects to DataContext.

How DataContext helpful to WPF binding Techniques.

Download Source Code And Video Explaining about DataContext Property in WPF

Description:

DataContext:

DataContext is the Dependency Property which holds the Data. Here Data can be any type, it can be an CLR Object, a DataSet, XMLDataProvider, Any Collection Object etc. Almost all controls in wpf user interfaces are derived from Dependency Object so either Panel controls or Content Controls can have this Property.

This Dependency Property has "Value Inheritance " feature means if you set Data Context as Data Object on Parent element then all of its descendent elements or children elements can reference to Data assigned to parent DataContext. i.e All the child elements are bind against to the Data Object of parent control DataContext unless if we specify to bind against to other Objects.

If DataContext is set on parent elements then no need to set binding source to children elements , we need to specify the path only for children elements. Let us see with example.

I have class called MobileShop with three properties.

Now i will show these three properties in three textboxes by setting MobileShop Object as DataContext for Window

Here is the XAML Code How the Window Looks like and How Child Elements access the DataContext of the Parent Control.

If you see the above xaml code for accessing the local class file in XAML code first i created a namespace reference to local as below

xmlns:local="clr-namespace:WpfApplication1"

Now we can able to access project resources using local reference in XAML code like below

In the above lines i created an instance of MobileShop Class added data to properties and assigned that object as DataContext for Window Element. So for all the child elements we have to set the path only no need to set source again.

Source Vs DataContext:

There is a situation where parent element is set to DataContext object and Child Element bind to Source of another Object then Child Element binds to Source Object Only. Here child element checks first if any Source or RelativeSource bind to any object, if set it will bind to that object, if Source or RelativeSource is not set then WPF Searches up in the element tree for DataContext of the Parent elements if it finds any non null Object then that objects used for Binding. This type of Binding use full when multiple properties are bind to Single Source.

Here is one example using same MobileShop class , where we will create two objects for this class and one object will bind to parent element as earlier, another bind to child element directly as source.

Conclusion:

In this way DataContext Property is useful when setting multiple properties to Single Source.

If you are binding single property then it is better to set as source for the element because of easy debugging i.e all the binding information exist in one place rather than searching up in the element tree for nearest DataContext. This DataContext defined in FrameworkElement Class.

Don't forget to Comment and Share to our friends if you like this post. Thank You.

WPF Tutorials

2013-08-14T16:44:00.000+05:30

WPF Tutorials and How to Examples

Hi, this page contains the WPF Tutorials and How to examples Concept wise, i will update the WPF tutorials whenever updated.If you are new to WPF you can go through them in sequential order so that you can learn wpf from basics.

WPF Tutorials- Windows Presentation Foundation

WPF Basics:

XAML Basics:

Data Binding in WPF:

MVVM Model(Model -View-View-Model):

Layout Controls in WPF:

Overview of WPF Layout Controls.

Grid Layout Control in WPF.
Canvas Layout Control in WPF.
StackPanel Layout Control in WPF.
DockPanel Layout Control in WPF.
WrapPanel Layout Control in WPF.

WPF DataBindings:

Different Types of DataBinding Mode in WPF.
AttachedProperty in WPF.
Dependency Property in WPF.
INotifyPropertyChanged Interface in WPF.
ValueConverters in WPF.
DataContext Property in WPF.
UpdateSourceTrigger in WPF.

Controls in WPF:

ListView Control in WPF and Usage.
DataGrid Control in WPF and Usage.
MediaElement Control in WPF and Usage.

Brushes in WPF:

SolidColorBrush in WPF and Usage.
LinearGradientBrush in WPF and Usage.
RadialGradientBrush in WPF and Usage.
ImageBrush in WPF and Usage.

Transformations in WPF:

Rotate Transformation in WPF
Skew Transformation in WPF
Scale Transformation in WPF.

Translate Transform.

2D Drawings and Shapes in WPF:

Basic Drawings and Shapes in WPF.

How to Examples

How to move a line from top to bottom using wpf doubleanimation.

Routed Events in WPF:

Triggers in WPF:

Event Triggers in WPF
Property Triggers in WPF
Data Triggers in WPF

Styles and Resources in WPF:

Animations in WPF:

WPF Interoperability:

WPF UserControl:

Speech Synthesis in WPF:

Keep visiting this page i will update it everyday with new posts. Thank You.

UpdateSourceTrigger Property in WPF Binding Example

2013-08-14T13:26:00.000+05:30

Introduction:

In this article i will explain

What is the purpose of UpdateSourceTrigger Property,
How to use UpdateSourceTrigger Property in WPF Binding,
What are the different Options available for UpdateSourceTrigger Property etc.

Download Source Code And Video Explanation of UpdateSourceTriggerUsage

Description:

UpdateSourceTrigger is the one of the Property of Binding element in WPF. This Property defines the timing of binding source updates. There are two binding modes which updates the source i.e OneWayToSource and TwoWay.

So in this Two Modes we need specify when should occur the binding source updation.

UpdateSourceTrigger Property has three properties.

LostFocus

PropertyChanged

Explicit.

To understand this with example, add new window to wpf project and add new window which contains a ListBox with List of colors and textbox whose Text, Background properties are bind to ListBox.SelectedItem.Content Property.

XAML Code is:

LostFocus: If set, Binding Source will be updated when target control lost foucs. Now run the above example type one color in textbox and press tab you will notice that listbox is changed and Textbox background is changed.

PropertyChanged: If UpdateSourceTrigger Property is set to PropertyChanged, then source is updated with target data whenever change occurs in Target. Now Change UpdateSourceTrigger Property in our example to PropertyChanged. Now run the example and type in textbox, then ListBox is updated with this content.

Explicit: If UpdateSourceTrigger Property is set to Explicit, then Binding source is updated only when BindingExpression.UpdateSource( ) method is called externally. Now in our example set the UpdateSourceTrigger Property to Explicitly and add a button to window. Now in button click write below code.

Now run our example and type one color in textbox and then click the button. Now the ListBox is updated with this data instead updating while typing or lost focus.

Default: Instead of these three options, Default option exist which will take place when we didn't specify any option in UpdateSourceTrigger Property. This Default option takes any of three options based on the Dependency Property of Target Control. For example Text Property of TextBox control has default option is LostFocus.

For More Graphical explanation Watch the Video Explaining the UpdateSourceTrigger Property

Conclusion:

I hope you are clear about How to use UpdateSourceTrigger Property in wpf bindings.

Don't Forget to Comment and Share for our friends if you like this post. Thank You.

Binding Modes in WPF with Example

2013-08-14T09:56:00.000+05:30

Introduction:

In this article will see purpose of Mode property in Data Binding, What are the different Data Binding Modes available in WPF, When to use each of these binding modes etc.

Description:

Mode is the one of the property of the Binding Element. Mode attribute defines the Data Binding Mode which determines how data flows between source and target.

Four Types of Data Binding Modes available.

OneWay
OneTime
OneWayToSource
TwoWay

For understanding Binding Modes briefly let us take an example which contains a ListBox, a TextBlock, a TextBox. ListBox contains List of Colors, Selected value of ListBox is binded to Background and Text dependency properties of TextBlock, and Text property of TextBox.

XAML Code Looks like below.

OneWay:

If Binding Mode is OneWay means whenever the Source Data is changed then that data is reflected in Target UI. Suppose in the above example we binded the listbox's SelectedValue.Content to TextBox and TextBlock's Background and Text Properties. So whenever we select another ListBoxItem then that value is Update in Target i.e in TextBox and TextBlock.

OneWay Binding

Note: If Source Changes then only UI will Updated. Use this only when you want to display read only data in the UI.

OneTime:

If Binding Mode is OneTime, then it sends data from source to target, but it does this only when application started or DataContext changes. So in our example change the Mode Attribute value to OneTime and set the ListBox's SelectedIndex to 0 then run the example you will notice that only default value is shown in targets, eventhough we select another color then target's value can not change.

OneTime Binding Mode

We can use this to show read only data in control as it was loaded. We can use this to compare the changes occurred in the UI with Default values. This is best when source Doesn't Implement INofityPropertyChanged Interface.

OneWayToSource:

This mode is reverse to OneWay Mode, When Mode is set to OneWayToSource then if target value is changed by user then that value is updated to source. In our example change the Mode to OneWayToSource and run the example you will notice that target's can not have any values, Now write any color in TextBox, when focus leaves then source will be updated for default selectedindex not the current selected index. But here Changed Data in Source can not be updated in target.

OneWayToSource Binding Mode

We have to use this Binding Mode when user can able to change the source data and changed data can not be updated in Target UI.

TwoWay:

If you set Mode to TwoWay then Whenever Source Property Changed then Target will be udpated, similarly if target values changes, changes will be updated in source property. Set the Mode two way in our example run it, You will notice that whenever ListBox selection changes it will be updated in TextBlock and TextBoxes. If we change the value in TextBox then Source is Updated and also target updated with these values.

TwoWay Data Binding

Use this binding when user can able to change data source and that changes will be updated to targets.

Default: In addition to these four Binding Modes Default Binding Mode exist. If you don't specify any binding Mode in Binding element then Default will take place. Defualt binding mode choose binding mode depending upon the target controls Dependency Property. For Example TextBox control Text property has binding mode as TwoWay in the same it will take for other controls.

UpdateSourceTrigger:

It is the property of Binding element, indicates or defines when should be the target value updated in the source.

Conclusion:

I hope you are clear about binding modes in wpf. So what do you thinking about binding modes now.

Don't forget to Comment and Share for our friends if you like this post. Thank You.

Related Posts:

Introduction to Object Oriented Programming(oops) Concepts in C#.Net With Examples

2013-08-08T11:45:00.000+05:30

Object Oriented Programming Concepts in C#.Net:

Introduction:

This page contains list of Object Oriented Programming Concepts i have written in this blog. You can find other Pages About .Net Technologies like WPF,Asp.Net, C#.Net,Vb.Net and Ado.Net.

All the tutorials are given with examples. Go through it you will find enough information. This page is sitemap for oops concepts in this site.

Description:

Access Specifiers in C#.Net

This Article explains what are the access specifiers available in C#.Net and How to use them with example.

Access Specifiers in C#.Net in Diagrammatic Format

This Article gives you clear picture Access Modifiers for easily remembering hierarchy of usage of Access Specifiers.

Abstract Classes and Abstract Methods in C#.Net

This Oops Concept focuses on Abstract Types in C#.Net. Learn about how to create abstract class and Abstract methods and usage.

Static Classes and Static Class Members

This Article focuses on creation of Static Classes in Oops Programming and How to Consume them in C#.Net

Sealed Classes and what is the use of them

This Article gives when to use Sealed Classes and what is their purpose.

Partial Class in C#.Net

This Article gives brief explanation about How partial classes helps developers to work on one class at a time by multiple developers.

Interfaces in C#.Net

This Article focuses on purpose of interfaces and when to use interfaces.

How to identify the particular type of children control in a container control

Some times while programming we need to identify the particular type of controls and assign them certain settings in code behind file so in that case this article gives you how to catch the elements of container control in code behind file dynamically.

I will update this whenever i post any new articles about Oops Programming.
Keep Visiting Thank you.

How to add, read, clear the text content in richtextbox control in wpf

2013-08-08T09:12:00.001+05:30

How to get, set, clear the text in richtextbox control in wpf

Introduction:

In this article you will know

how to assign the text to richtextbox in wpf,
how to read and clear the text from richtextbox,
how to enable the spell check for richtextbox in wpf,
what is the replacement text property for richtextbox,
how to set the margins for richtextbox paragraphs.

Download Source Code and Video explaining How to add, read, clear the text in RichTextBox

Description:

In the previous articles i explained basic WPF concepts like What is wpf and it's features, Wiindows Forms vs WPF Future, what is XAML and it's compilation process,WPF Architecture etc.

What is the replacement Text property for RichTextBox in WPF:

Unlike other controls in wpf, richtextbox doesn't have content as property for setting content. Richtextbox has Document property to set or get the content or text. Here this Document is FlowDocument type. Here this FlowDocument may contain multiple paragraphs.

How to add text to richtextbox control:

As the Document Property of the RichTextBox is the FlowDocument type so we have create an object of type FlowDocument, and add paragraphs to Blocks property of FlowDocument and Finally assign this FlowDocument to Document Property of RichTextBox Control.

Here is the Code showing how to add text to richtextbox control in WPF using C#.Net

Vb.Net Code for addding text to richtextbox

How to read Text from RichTextBox Control:

To read text from RichTextBox FlowDocument type we have to use TextRange( ).

Code to Read text RichTextBox using C#.Net

Vb.Net Code

How to Clear Text in RichTextBox:

While Adding text to richtextbox, we added paragraphs to Blocks property of FlowDocument type, so for clearing text we have to clear the Blocks of Document in the following two ways.

C#.Net Code:

Vb.Net Code:

Setting Margin for RichTextBox paragraphs:

While adding text using paragraphs we may get more space between para's in richtextbox so to set the margin between paragraphs use below code in resources section of XAML code.

Enabling Spell Check:

RichTextBox has spell check feature this can be enabled by setting

richTextBox1.SpellCheck.IsEnabled = true;

You can find the video explained with example on how to add, read, clear the content in wpf richtextbox control

Conclusion:

I hope you are clear about reading, adding ,clearing the text from richtextbox control. I hope you will see the WPF Tutorials section for More Tutorials and How to's .

Don't forget to Comment and Share if you like this post for our friends. Thank You.

How to perform select, insert,update,delete operations using SqlCommand Object C#.Net and Vb.Net

2013-08-07T09:00:00.000+05:30

Select,Insert,Update,Delete Operations on Database:

Introduction:

In this article you will learn how to use SqlCommand Object in Ado.Net for doing Select, Insert, Update, Delete operations against database.

You will also learn different overloading methods for instantiation of SqlCommand Object, How to set CommandText as insert, update,delete sql statements, what are the different methods available for execution of queries against database, How to use ExecuteScalar( ), ExecuteReader( ), ExecuteNonQuery( ) methods.

Description:

In the previous articles i explained Introduction to Ado.Net Part1, Part2 and How to establish connection to database. In Ado.Net next step is to learn about SqlCommand Object.

SqlCommand:

While doing database operations using Ado.Net , after establishing connection to database next step is to Set the CommandText in SqlCommand Object.

SqlCommand Object is exist in System.Data.SqlClient namespace which is defined in System.Data.dll assembly. SqlCommand object has four overloads exist i.e

As you saw we can instantiate the SqlCommand Object in four ways.

SqlCommand Methods:

SqlCommand Class provides three methods to execute queries against database.

These are

ExecuteReader( ) for Select Operation
ExecuteNonQuery( ) for Insert, Update, Delete operations
ExecuteScalar( ) for Getting Single Value.

ExecuteReader( ):

If you want to perform select operation on database that returns data as rows and columns then you have to call ExecuteReader( ) method after setting CommandText as Sql Select Statement. This method returns object of the class DataReader which holds data as rows and columns.

Below code contains how to set the CommandText as Sql Select Statement in C#.Net and Vb.Net. I am using Dept table which have Id,Dname,Loc columns.

C#.Net Code

SqlDataReader ObjRdr = null;
            try
            {

SqlConnection ObjCon = new SqlConnection("Database=cs9db; data source=(local); integrated security=sspi;");
                
                // Opening the connection
                ObjCon.Open();
                
                // Instantiation of SqlCommand Object with a query and Connection reference
                SqlCommand ObjCmd = new SqlCommand("Select DName from Dept", ObjCon);
                // Calling ExecuteReader() method
                ObjRdr = ObjCmd.ExecuteReader();

// Print the Deptname for each record
                while (ObjRdr.Read())
                {
                    Console.WriteLine(ObjRdr[0]);
                }

}
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
            }
            finally
            { // if reader is open then closing the reader
                if (ObjRdr != null)
                {
                    ObjRdr.Close();
                }
                // If Connection is open then closing the conneciton
                if (ObjCon.State != ConnectionState.Closed)
                {
                    ObjCon.Close();
                }
            }

Vb.Net Code

Dim ObjRdr As SqlDataReader = Nothing
Try

Dim ObjCon As New SqlConnection("Database=cs9db; data source=(local); integrated security=sspi;")

' Opening the connection
 ObjCon.Open()

' Instantiation of SqlCommand Object with a query and Connection reference
 Dim ObjCmd As New SqlCommand("Select DName from Dept", ObjCon)
 ' Calling ExecuteReader() method
 ObjRdr = ObjCmd.ExecuteReader()

' Print the Deptname for each record
 While ObjRdr.Read()
  Console.WriteLine(ObjRdr(0))

End While
Catch ex As Exception
 Console.WriteLine(ex.Message)
Finally
 ' if reader is open then closing the reader
 If ObjRdr IsNot Nothing Then
  ObjRdr.Close()
 End If
 ' If Connection is open then closing the conneciton
 If ObjCon.State <> ConnectionState.Closed Then
  ObjCon.Close()
 End If
End Try

ExecuteNonQuery( ):

If you want to perform any DML operation like insert, update, delete then you have to use ExecuteNonQuery( ) methods. It returns an integer specifying that number of rows affected. If any error occur it returns -1.

Below code contains how to set the CommandText as DML statement and How to call ExecuteNonQuery() method in C#.Net and VB.Net.

C#.Net Code

try
            {
                SqlConnection ObjCon = new SqlConnection("Database=cs9db; data source=(local); integrated security=sspi;");
                
                // Opening the Connection
                ObjCon.Open();

// Insertion

// Prepare Command String
                string InsertStmt=@"Insert into Dept(DName,Loc) values('Sales Dept',30)";
                
                // Instantiation of SqlCommand Object with CommandText
                SqlCommand ObjCmd = new SqlCommand(InsertStmt);
                
                // Updation
                // Instantiation of SqlCommmand Object 
                string UpdateStmt = @"Update Dept set DName='IT Dept' where Deptno=30";
                
                SqlCommand ObjCmd = new SqlCommand();
                ObjCmd.CommandText = UpdateStmt;

// Deletion

string DeleteStmt = @" Delete from Dept where Deptno=30";
                SqlCommand objCmd = new SqlCommand();
                objCmd.CommandText = DeleteStmt;

// Adding Connection object to Command Object
                ObjCmd.Connection = ObjCon;
                
                // Calling ExecuteNonQuery() method
              int Count=ObjCmd.ExecuteNonQuery();
              if (Count > 0)
              {
                  Console.WriteLine("DML statement Executed Successfully");
              }
              else
              {
                  Console.WriteLine("Error Occured in Executing DML Statement");
              }

}
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
            }
            finally
            { 
                // If Connection is open then closing the conneciton
                if (ObjCon.State != ConnectionState.Closed)
                {
                    ObjCon.Close();
                }
            }

VB.Net Code

Try
 Dim ObjCon As New SqlConnection("Database=cs9db; data source=(local); integrated security=sspi;")

' Opening the Connection
 ObjCon.Open()

' Insertion

' Prepare Command String
 Dim InsertStmt As String = "Insert into Dept(DName,Loc) values('Sales Dept',30)"

' Instantiation of SqlCommand Object with CommandText
 Dim ObjCmd As New SqlCommand(InsertStmt)

' Updation
 ' Instantiation of SqlCommmand Object 
 Dim UpdateStmt As String = "Update Dept set DName='IT Dept' where Deptno=30"

Dim ObjCmd As New SqlCommand()
 ObjCmd.CommandText = UpdateStmt

' Deletion

Dim DeleteStmt As String = " Delete from Dept where Deptno=30"
 Dim objCmd As New SqlCommand()
 objCmd.CommandText = DeleteStmt

' Adding Connection object to Command Object
 ObjCmd.Connection = ObjCon

' Calling ExecuteNonQuery() method
 Dim Count As Integer = ObjCmd.ExecuteNonQuery()
 If Count > 0 Then
  Console.WriteLine("DML statement Executed Successfully")
 Else
  Console.WriteLine("Error Occured in Executing DML Statement")

End If
Catch ex As Exception
 Console.WriteLine(ex.Message)
Finally
 ' If Connection is open then closing the conneciton
 If ObjCon.State <> ConnectionState.Closed Then
  ObjCon.Close()
 End If
End Try

ExecuteScalar( ):

If you want to execute any query that returns single value then you have to call ExecuteScalar( ) method of Command Object. It returns the single value in the form of object type, you have to cast it to use the value.

Below code contains how to call ExecuteScalar( ) method for Getting Single value result in C#.Net and VB.Net.

C#.Net Code

try
            {
                string SelectStmt = "Select Count(*) from dept";
                SqlConnection ObjCon = new SqlConnection("Database=cs9db; data source=(local); integrated security=sspi;");
                // Opening the Connection
                ObjCon.Open();

//Instantiation SqlCommand Object

SqlCommand objCmd = new SqlCommand();
                objCmd.Connection = ObjCon;
                objCmd.CommandText = SelectStmt;

//Calling ExecuteNonQuery() method
                Count=(int)objCmd.ExecuteScalar();

}
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
            }
            finally
            {
                // If Connection is open then closing the conneciton
                if (ObjCon.State != ConnectionState.Closed)
                {
                    ObjCon.Close();
                }
            }

VB.Net Code

Try
 Dim SelectStmt As String = "Select Count(*) from dept"
 Dim ObjCon As New SqlConnection("Database=cs9db; data source=(local); integrated security=sspi;")
 ' Opening the Connection
 ObjCon.Open()

'Instantiation SqlCommand Object

Dim objCmd As New SqlCommand()
 objCmd.Connection = ObjCon
 objCmd.CommandText = SelectStmt

'Calling ExecuteNonQuery() method

Count = CInt(objCmd.ExecuteScalar())
Catch ex As Exception
 Console.WriteLine(ex.Message)
Finally
 ' If Connection is open then closing the conneciton
 If ObjCon.State <> ConnectionState.Closed Then
  ObjCon.Close()
 End If
End Try

Conclusion:

I hope you know the importance of SqlCommand Object in Ado.Net, How to set the CommandText , how to call ExecuteScalar( ), ExecuteReader( ), ExecuteNonQuery( ).

In next articles will see how to pass parameters to SqlCommand Object, How to use stored Procedures in SqlCommand .

Don't forget to Comment and Share if you like this post for our friends. Thank You.

How to set connectionstring for SqlConnection Object to connect to sql server database with example

2013-08-06T14:12:00.000+05:30

Setting Connection String for Sql Server Database

Introduction:

In this article you will learn about

how to set connection string parameter in SqlConnection Object,
how to instantiate the SqlConnection,
How to open the connection,
How to pass the connection object to other ADO.NET objects,
How it perform operations with other Ado.Net Objects,
How to close the connection.

You can also find Introduction to Ado.Net Part1 and Part2 to know briefly about Ado.Net Data Providers.

Description:

While doing any crud operations with sql database first we have to create connection to sql server database. To Connect with sql server database from .net applications Ado.Net Provides two providers OledbConnetion and SqlConnection Object.

SqlConnection Object:

To interact with database, you must have connection to it. The Connection Object helps to identify the datasource, database, User Id and Password etc connection string parameters required to connect to a database. So this SqlConnection object is used by SqlCommand object so that they will know which database to execute query.

SqlConnection object exist in System.Data.SqlClient namespace which is defined in System.Data assembly.

SqlConnection object has following constructors

i.e SqlConnection()
SqlConnection(string ConnectionString)

Here Connection String is a collection of attributes where it contains following attributes

- Data Source
- User Id and Password
- Trusted_Connection or Integrated Security
- Database or Initial Catalog
- Provider

I explained these briefly in Connection String Parameters for sql and Oracle databases.

Sql Server Database provides two modes for connecting to it from .Net applications.

Sql Server Authentication.

"Provider=SqlOledb;User Id=Sa;Password=;
Database=[;Data Source=]"

Windows Authentication.
In windows authentication no need to provide User Id and Password parameters

"Provider=SqlOledb; Trusted_Connection= true/ Integrated Security= SSPI;
Database=[;Data Source=]"

SqlConnection Object goes through these sequence of operations while communicating with data sources.

1). Instantiate of SqlConnection.

2). Open the Connection.

3). Pass the connection to other Ado.Net objects.

4). Doing database operations along with other Ado.Net Objects.

5). Closing the Connection

In the below code i explained these five steps in clear manner

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

// Importing namespaces required 
using System.Data;
using System.Data.SqlClient;

namespace LINQ_Practice
{
    class SqlConnentionDemo
    {
        static void Main(string[] args)
        {
            // 1. Instantiation of SqlConnection Object
            // Windows Authentication
            //SqlConnection ObjCon = new SqlConnection("data source=(local); trusted_Connection=true; initial catalog=cs9db");
            // Sql Server Authentication
            SqlConnection ObjCon = new SqlConnection("data source=(local); userid=sa;password=9290812112; initial catalog=cs9db");
            SqlDataReader ObjRdr = null;
            try
            {
                // 2. Opening the connection
                ObjCon.Open();
                //3. Passing connection to other Ado.Net Objects.
                SqlCommand ObjCmd = new SqlCommand("Select * from Dept", ObjCon);
                
                // 4. Performing database operations with other Ado.Net Objects.
                ObjRdr = ObjCmd.ExecuteReader();

// Priniting the Result
                while (ObjRdr.Read())
                {
                    Console.WriteLine(ObjRdr[2]);
                }
                Console.ReadLine();

}
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
            }
            finally
            {
                // if reader is open then closing the reader
                if (ObjRdr != null)
                {
                    ObjRdr.Close();
                }
                //5. If Connection is open then closing the conneciton
                if (ObjCon.State != ConnectionState.Closed)
                {
                    ObjCon.Close();
                }
            }
        }
    }
}

As you saw in code at 1. we are creating an instance of SqlConnection class by specifying Connection String in both Sql Server and windows authentication modes. We can use one mode. at step 2. we opened the connection with database by calling Open( ) method of SqlConnection Object.

At step 3 we added SqlConnection Object to SqlCommand as parameter. At step 4 Connection object perform database operations along with SqlCommand and SqlDataReader object. We will see SqlCommand and SqlDataReader in later. At Step 5 we closed the connection. It is always good practice to know the status of the connection before closing the connection.

Conclusion:

I hope you understand the purpose and need of SqlConnection Object, How to pass Connection String parameters as key/value pairs while instantiation, How it is used in database operations, Finally how to close the Connection.

Don't forget to Comment and Share if you like this post for our friends. Thank You.

Connection string parameters for Sql database and Oracle database with Example

2013-08-06T12:16:00.000+05:30

Connection string parameters for SqlConnection ,Oralce Connection objects to Connect with Sql Server and Oracle databases

Introduction:

In this article you will learn what are the different connection string parameters need to set while connecting with either Sql Database or Oracle database.

Description:

In my previous article Introduction to Ado.Net part1 i mention that Creating connection is the first step while connecting with data sources.

So to establish connection with Sql Server database we use SqlConnection object in the same manner OracleConnection object to connect with Oracle database.

Constructors are as follows

SqlConnection(string ConnectionString)

OralceConnection(string ConnectionString).

Here ConnectionString is a collection of attributes that are required while connecting with datasources.

Connection String Parameters:

Here this connection string attributes has some parameters exist. Some of these parameters are common to both SqlConnection and OracleConnetion objects. These are

- Provider

- Data Source

- User Id and Password

- Database or Initial catalog

- Trusted_Connection or Integrated Security

- DSN

we will see each these in detail now.

Provider:

As i mentioned in Ado.Net introduction , provider is required while connecting with datasource. Ado.Net provides different types of providers for connecting different types of data sources.

Here is the list Providers that Ado.Net Provides.

Oralce Msdaora

SqlServer Sqloledb

Ms-Access or Ms-Excel Microsoft.Jet.Oledb.4.0

Ms-Indexing Server Msidxs

Data Source:

It is the name of the machine on which the our required database exist, it is optional when our database exist on local machine, it is required when database is on remote machine.

User Id and Password:

As we know databases store secured information we need to provide User Id and Password for connecting with databases in secured mode.

Oracle scott/tiger

Sql Server sa/

Database or Initial Catalog:

These attributes are required only while connecting with Sql Server Database as it contains multiple databases. It is the database name to which we need to connect.

Trusted_Connection or Integrated Security:

These attributes also required only while connecting with Sql Server Database in Windows authentication mode only. In this case we don't need to provide User Id and Password attributes in the Connection String.

we provide Trusted_Connection = true or Integrated Security=SSPI

Here SSPI- Security Support Provider Interface.

DSN:

This attribute is required while connecting with data sources using ODBC Drivers.

Examples for Sql Server and Oracle Connection Strings:

Oracle Connection String:

"Provider=Msdaora;User Id=Scott;Password=tiger [;Data Source=]"

Sql Server Connection String:

Sql Server Authentication :-

"Provider=SqlOledb;User Id=Sa;Password=;
Database=[;Data Source=]"

Windows Authentication:-

"Provider=SqlOledb;Trusted_Connection= true / Integrated Security = SSPI;
Database=[;Data Source=]"

Conclusion:

I hope you are Clear about Setting Connection string for Sql Server and Oracle databases.

Don't forget to comment and share if you like this post for our friends. Thank You.

Ado.Net Tutorial: Introduction to Ado.Net- Part2 Sending SqlCommand object and Getting Result using DataReader.

2013-08-06T10:12:00.000+05:30

Introduction to Ado.Net:

Introduction:

This is Second Part of Ado.Net Introduction part1. In the first part i explained Basics of Ado.Net and How to Establish Connection With Database.

Now in this part we will see how to send request using Sql Command Object and How to Get the Result from Database using DataReader Object.

Description:

2). Sending Request as an Sql Statement:

So After Establishing Connection with the Database next step is sending a request as an Sql Statement.We will use command object to do this thing. Command Object have following Constructors.

Command( )
Command(string CommandText, Connection Conn)

CommandText: Here Command Text means any sql statement like select,insert,update,delete statements or Stored Procedure name.

Properties:

Connection: Gets or Sets the Connection associated with the Command Object.
CommandText : Gets or Sets the Sql Statement Associated with the Command Object.

We can create the Command Object in the following manner

Note: One thing you should remember here i.e You have to prefix the data provider api prefix before Connection and Command Classes.

3). Capturing Results given by the data source:

Now we completed step2 of Sending request as an Sql Statement. Now our next step is to Get the result using Sql Statement in the Command Object.

Command Object itself have the methods to capture the results. These are

- Call ExecuteReader( ) method to Execute the Select statement in Command Object which returns data as Rows and Columns. This method returns an object of class DataReader which contains data that is retrieved from data source in the form of rows and columns.

-Call ExecuteScalar() method when we want to execute a Select Statement that returns a single value result. The method returns result of the query in the form of a object. We have to cast it our required type later.

-Call ExecuteNonQuery( ) method when we want to execute any Statement other than select, like Insert, Update, Delete etc. The method returns a numeric value telling the number of rows affected by the statement.

So Calling one of above three methods to capture the results is our third step.

Next step is to retrieve the data from Data Reader:

DataReader class holds the data in the form Rows and Columns. To access data from this DataReader it provides methods. They are

GetName(int ColumnIndex):

Returns the Name of Column in the Specified Column Index. Here Return type is String.

Read( ):

If we call this method, it moves the record pointer to next record in datareader object. It returns true if datareader object contains data in the next row, returns false if it contains no data. Return type is boolean.

GetValue(int ColumnIndex ):

We use this method to get the Column values from the row pointer is Pointing.

We can access the row pointer in the following ways

DR[Column Index] Return Object Type

DR[Column Name] Return Type is Object

GetNextResult( ):

Suppose if your Select Statement returns multiple tables then we need to move between tables to access them. So GetNextResult( ) method used to move the pointer to next table in DataReader object. It returns true if the Datareader object contains table else returns false.

Conclusion:

I hope you got full pledge information on Introduction to Ado.Net and Ado.Net Object Communication Model. In later sessions we will see how to establish Connection with Sql Server Database, How to work with SqlCommand Object ,How to retrieve Data From DataReader with Example.

Don't Forget to Comment and Share if you like this post for our friends. Let me know if you have any other requirement. Thank You.

Ado.Net Tutorials: Introduction to Ado.Net - Part1 Establishing Connection with DataBase

2013-08-05T21:03:00.000+05:30

Introduction to ADO.NET:

Introduction:

If you are new to .Net Technologies, want to get job in .net then start learning basics oops concepts and then learn Ado.Net Tutorials.

This article will give you brief introduction to ADO.NET in .NET like

What is Ado.Net,
What Ado.Net Provides you to communicate with data sources,
What are the providers provided by Ado.Net to Communicate with Data Sources like Flat Files(Text Files,XML FIles etc), Databases(Oracle, Sql Server, DB2, Teradata, MySql, Ms Access, etc),
Architecture of Ado.Net, Object Model of Ado.Net,
How to perform CRUD operations on Databases etc things.

Description:

It is a set of libraries included in Mircrosoft .Net Framework for Data Source communication from .Net Applications. These libraries are in the form of Drivers and Data Providers. Ado.Net was designed as an extension for older ADO which is unmanaged.

The following are the Data Providers provided by Ado.Net

ODBC Data Provider.
Oledb Data Provider.
Oracle Data Provider.
Sql Data Provider.

ODBC Data Provider:

This Data Provider used for communicating with data sources using ODBC interface.
These data sources are older one.

API Prefix is: Odbc

Namespace: System.Data.Odbc.

Oledb Data Provider:

This Data Provider used for communicating with data sources like Files, Databases,Indexing servers etc.

API Prefix is: Oledb

Namespace: System.Data.Oledb.

Oracle Data Provider:

This Data Provider used for communicating with only Oracle Database using OracleClient Provider.

API Prefix: OracleClient.

Namespace: System.Data.OracleClient.

Sql Data Provider:

This Data Provider used for communicating with only Sql Server Database using SqlClient Provider.

API Prefix: SqlClient.

Namespace: System.Data.SqlClient.

System.Data,System.Data.Oledb, System.Data.SqlClient, System.Data.Odbc all these namespaces are defined under same assembly i.e System.Data.dll where as System.Data.OracleClient namespace defined in System.Data.OracleClient.dll Assembly.

All the above four namespaces contains same set of classes as follows : Connection, Command, DataReader, DataAdapter, CommandBuilder, Parameter etc.

To discriminate between each other these class names are prefixed by their API Prefixes Such as

OdbcConnection OdbcCommand

SqlConnection SqlCommand

OledbConnection OledbCommand

OracleConnection OracleCommand.

Most of the .Net Applications Use Database as Sql Server So we will go deeply on How to Communicate with Sql Server using SqlClient Data Provider.

If you want to see how this Data Providers Communicate with Data Stores then look at the below diagram.

If you see the Ado.Net Object Communication System in the above image you find that it requires three steps to communicate with Data Stores.

1). Establishing a Connection with Database or Data Store Connection Object.

2). Sending Request i.e in the form of Sql Statement using Command ,Adapter objects.

3). Receiving result using Reader Object or DataSet Object.

Establishing Connection with DataStore:

To Interact with Database we must have connection with it. We use Connection Object to Establish a channel between database and client for communication.

This Connection Object have following Constructors i.e

Connection( )

Connection( string ConnectionString)

ConnectionString is a collection of attributes that are necessary for connecting with a DataSource, those are:
     -Provider
     -Data Source
     -User Id & Password
     -Database or Initial Catalog
     -Trusted_Connection or Integrated Security
     -DSN

Provider:

Provider is required for connecting with any Data Store. we have to use different provider for each Data Store.

Oracle                                     Msdaora
Sql Server                               SqlOledb
MS-Access or MS-Excel        Microsoft.Jet.Oledb.4.0
MS-Indexing Server                 Msidxs

Data Source:

It is the name of the machine on which the Data Source exist. If the Data Source exist in the local machine then it is optional. If Data Source exist in remote machine then we have to mention it in Connection String.

User Id and Password:

As Database's are Secured with Roles and Users, then it is necessary to mention the User Id and Password in the Connection String.

Sql Server sa/

Oracle scott/tiger

Database or Initial Catalog:

As a single Data Source may contain multiple Databases then it is necessary to mention the Database name in Connection String. These attributes used only for connecting with Sql Server Database.

Trusted_Connection or Integrated Security:

These credentials are used for Security purposes while connecting with Sql Server Database in windows authentication mode. If you use Windows Authentication Mode by specifying these credentials then no need to mention the User Id and Password in Connection String.

DSN:

These Attributes are required while connecting with data stores using ODBC Providers.

Connection String for Oralce:

Connection String for Sql Server:
"Provider=SqlOledb;User Id=Sa;Password=<pwd>; Database=<db name>[;Data Source=<server>]" In case Windows Authentication "Provider=SqlOledb;Trusted_Connection= true/ Integrated Security=SSPI; Database=<db name>[;Data Source=<server>]" SSPI: Security Support Provider Interface.

Members of Connection Class:

1. Open( ): Opens the Connection with Data Store or Database.

2. Close( ): Closes the Connection that is Open.

3. State: Gets the Status of the Connection.

4. ConnectionString: Gets or Sets the Connection String Associated with the Connection Object.

We can create the connection Object as follows
Connnection ObjCon= new Connection(); ObjCon.ConnectionString = "<connection String>"; or Connection ObjCon = new Connection("<connection String>");

You can also learn What are the different parameters for Connection String and How to set Connection for SqlConnection Object to Connect to Sql Server database.

Conclusion:

I hope You clear about things like what is Ado.Net, What are the Providers that Ado.Net Provides, How to communicate with data sources ,how to establish Connection with DataSources.

In this part we saw only Only How to create a Connection between Application and Database, So in the Second Part I will Cover remaining two things i.e how to send a request as Sql Statement, and How to receive Result.

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WPF Tutorial: Markup Extensions - XAML based and WPF based Markup Extensions, How to use Markup extensions for binding elements in WPF

2013-07-30T19:19:00.001+05:30

Markup Extensions in WPF:

Introduction:

In my previous articles i explained many articles on Asp.Net ,Oops Concepts and WPF.

Now we will see one successive WPF Tutorials i.e Markup Extensions in WPF.

Description:

Markup Extensions:

Markup Extensions are used to assign complex values to properties in XAML which are not possible using markup language. These markup extensions are enclosed in braces{} and keyword immeadiatly followed by the left brace, indicates which markup extensions you are using. For the markup extension you can set one or more properties.

Syntax:

Markup Extensions are classified into two categories.

XAML based Markup Extensions
WPF based Markup Extensions.

XAML based Markup Extensions:

These are the markup extensions that can be used in XAML but not possible to implement them through

C#.Net code as they have no classes in .Net Framework.

The following are XAML based Markup Extensions.

{x:null} - Used to assign null to a property using XAML markup.

{x:Type} - Used to specify the type of element in XAML markup.

{x:Type }

{x:Array} - Used to declare an array with in a XAML markup.

{x:Static} - Used to assign a static collection to a property of the control.

WPF based Markup Extensions:

These are markup extensions that can be used in XAML an also C#.Net code as they have classes in .Net Framework.

StaticResource :

Used to bind a style or Resource during compilation to use this Markup Extension in XAML, use the following syntax.

{StaticResource Resource Key =}
{StaticResource }

Dynamic Resource:

This is same as static resource except that it will bind the specified resource or style dynamically at run time and not during compilation.

To use this markup extension in XAML syntax is as follows

{DynamicResource ResourceKey=}
{DynamicResource }

Binding:

Used to Bind one control to another control. WPF support a feature called data binding which is
implemented using this Markup Extensions.

Elementname and Path.

ElementName property is used to specify name of the control to which you want to bind and Path is used
to specify property name of the control to which you want to bind.

It has property mode also to specify whether the Binding is oneway/twoway.

The following example takes two textboxes and a slider and Bind FontSize Property of one TextBox and Text Property of another TextBox to the value of the slider using Binding Markup Extension.

Add a window to the project and design as follows with a slider and two Textboxes by binding FontSize Property of the first Textbox and Text property of the another Textbox to the value of the slider as below.

You can find Tutorial for above Markup Extension Binding Example here

In the above example at runtime when you move the slider automatically the font size of the 1st textbox will change and also the value displayed in the 2nd textbox which is current value of the slider.

When you change the value of in 2nd textbox and press the tab then automatically value of the slider also changed because by default mode property of binding markup extension is set to twoway.

Conclusion:

I hope you got clear idea on WPF Markup Extensions.

This article is the one successive WPF Tutorials i.e

What is WPF and its features

Architecture of WPF

Windows Forms vs Windows Presentation Foundation

What is XAML and its parts

XAML Markup Extensions etc.

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WPF Tutorial: What is XAML?, XAML and Codebehind, Attribute and Property Element Syntax, XAML File Compilation Process

2013-07-28T09:46:00.001+05:30

Introduction to XAML, Attribute and Property Element Syntax, XAML File Compilation Process

Introduction:

In my previous articles i explained various articles on WPF, Asp.Net and Oops Concepts.

Now we will see importance of XAML in WPF, XAML vs Codebehind, Benefits of Attribute and Property Element Syntax and how the xaml file compiles. You can find other WPF Tutorials here.

Description:

What is XAML?

XAML called as Zammel stands for Extensible Markup Language. It is declarative language based on XML. It allows us to create UI declaratively which are visible. It gives flexibility to work individuals on designing and programming at a time. This was introduced in wpf and also used in Silverlight and WF and other technologies which supports XAML. XAML and along with it's powerful binding techniques we can create WPF Applications with less code written.

XAML vs Codebehind:

Writing Code with XAML is when compare to code behind file.

For the above XAML we can write it in code behind file as below

Attribute Syntax and Property Element Syntax:

In XAML we can write the code in two ways. i.e Attribute Syntax and Property Element Syntax.

Some times it is not possible to specify the property values using Attribute Syntax in that cases We can use Property Element Syntax.

Attribute Syntax and Property Element Syntax:

In the above case it is not possible to set background as LinearGradientBrush using Property Syntax so in this case you have to use Attribute Element Syntax as Above.

XAML File Compilation Process:

Every XAML file contains two files i.e XAML and XAML.CS files. When you compile your application it will first Converts XAML file into BAML and cs file into g.cs. For eg your application contains window1.xaml and window1.xaml.cs then compiler converts it to window1.baml and window1.g.cs files. BAML stands for Binary Applicaton markup Language and g stands for generated. Compiler uses BAML and g.cs file to generate executable files.

BAML is compiled version of XAML so it's not humarn readable format but it is more effcient for loading and parsing at runtme. BAML files are optimized for faster loading at runtime. The g.cs file code to load BAML from executable and create UI. These both fles are stored in Obj\Debug and Obj\Release folder of application's local folder respectively.

Reference :http://msdn.microsoft.com/en-us/library/ms752059.aspx

Conclusion:

I hope you got overview on what is xaml, how xaml file compiles, Attribute Syntax vs Property Element Syntax. It is One of Successive WPF Tutorials, You can find other WPF Tutorials here.

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WPF Animation: Moving a line from top to bottom using wpf doubleanimation

2013-07-26T12:09:00.000+05:30

Moving a line using WPF DoubleAnimation:

Introduction:

In my previous articles i had explained various articles on WPF , Asp.Net and Oops Concepts. Now we will see a simple example on how to move a line from top to bottom using WPF DoubleAnimation.

If you are new to WPF animation, If you want to move an element in wpf applications then this example will help you.

Description:

In WPF Three types of Animations are available.

From/To/By Animations
Key Frame Animations.
Path Animations.

In From/To/By Animations we will specify the from, To or By values , Based on these values animation occurs. We use From/To/By Animation to move a line from top to bottom.

First take a window in wpf project and then draw a horizontal line using following syntax. You can find more details on how to draw basic shapes and drawings in wpf.

In the above code we used line element to draw a line by specifying starting point(X1,Y1) and Ending Point(X2,Y2) and it is stroked with red color with thickness 5. It is placed as a child in a Canvas.

Now our task is to move this line element from top to bottom. Now in the Window Load event write below code.

In the Above code first we created a DoubleAnimation and assigned values for From ,To,Duration,AutoReverse and RepeatBehaviour.

Next to Apply this double animation to an element we have to use storyboard and set Target Name and Target Property and doubleanimation as child for storyboard.

StoryBoard has three events such Begin(), Pause(), and Stop() to control Animation.

See How it works

Moving Line from top to bottom using DoubleAnimation

Conclusion:

I hope this will help to you to move an element in wpf. Later i will explain more animation examples.

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Boxing and UnBoxing in .Net Interview Question

2013-07-19T20:29:00.000+05:30

Introduction:

One of the must and should question in interviews is What is Boxing and UnBoxing.

UnIntentionally while coding we will use this process many times. Let us explore this simple process.

What is Boxing:

It is the process of converting a value type into reference type. i..e Let us have a variable num which has value 100. It is a value type, now if we want to convert this to reference type i.e object type then this process is called as Boxing.

int num=100;

object obj=num;

One thing we should remember here is object is the base type of all data types in .net.

What is UnBoxing:

It is exactly reverse of Boxing, i.e Converting a reference type back to value type is called UnBoxing. But here explicit type casting require.

int num=Convert.Int32(obj);

Dialog Controls in Windows Forms, How to use ColorDialog,FolderBrowserDialog,FontDialog,OpenFileDialog,SaveFileDialog example.

2013-07-13T20:43:00.006+05:30

Dialog Controls in Windows Forms Application:

Introduction:

In my previous articles i explained various concepts on Asp.Net,WPF and Oops Concepts like Asp.Net Validation Controls Tutorial, Asp.Net Ajax Tutorial, WPF Features, WPF Architecture etc.

Now we will see what are the different types of DialogControls available in Windows Forms and How to work with these Dialog Controls in Our Applications with an example.

Description:

Dialog Controls in Window Forms help us to do some work quickly and easily and also provides us many options. In Visual Studio toolbox there is separate Tab available for these Dialog Controls in Windows Forms.

A Dialog Control Even if added to a form will not be displayed directly on the form. You will see them
in the bottom of the studio. To make them visible in run-time on the form we need to call a method
ShowDialog().

A Dialog Control will never perform any actions to use directly. We are only interfaces to perform the actions.They are responsible in displaying the available values to choose form to end users and returns back those values to application developer. Now it is the responsibility of application developer to perform
the necessary actions with values chosen by end users.

To capture the values that are chosen by end users application developers can make use of the following Properties.

Dialog Controls:

ColorDialog - Returns the Selected Color
FoloderBrowserDialog - Returns the Selected Folder Path.
FontDialog - Returns the Selected Font.
OpenFileDialog - Returns the Filename
SaveFileDialog - Returns the Filename.

Dialog Controls usage with an example:

Take a Form and add ColorDialog,FontDialog,OpenFileDailog,SaveFileDialog, Four Buttons and a PictureBox to form. Design them as shown in below.

Dailog Controls Example

2. Set the Text for four buttons as shown in above image i.e Change Color, Change Font, Load Image,Save Image.

3. Now in the Generate the Click event of Change Color Button write below Code.

DialogResult dr = colorDialog1.ShowDialog(); if(dr == DialogResult.OK) button1.BackColor = colorDialog1.Color;

This code will open the ColorDialog Box, end user will chose the one color then when he press ok , then we are applying that color to Button BackColor. If you Observe the code to open ColorDialog Box we are calling ShowDialog() method.

4. Now generate the Click event of Change Font Button and write below code.
DialogResult dr = fontDialog1.ShowDialog(); if (dr == DialogResult.OK) button2.Font = fontDialog1.Font;

Here also same in click event of Change Font Button we are opening FontDialog Box, User will chose one Font and Press Ok then we are applying selected Font to button Font.

5. Now generate the click event for Load Image Button and write below code.
openFileDialog1.Filter = "Image Files (*.jpg)|*.jpg|Bitmap Images (*.bmp)|*.bmp|All File (*.*)|*.*"; DialogResult dr = openFileDialog1.ShowDialog(); if(dr != DialogResult.Cancel) pictureBox1.ImageLocation = openFileDialog1.FileName;

Here we are opening OpenFileDailog Box by calling its ShowDialog() method. If you observe the we are filtering the type of files it needs to show when open using Filter Property of OpenFileDialog Control. In this button Click event user will Select an image then we are applying Selected Filename to Picturbox ImageLocation Property.

6. Now generate click event for Save Button and Write below Code.

Here we are giving a prompt to user whether you want to save this image? If user press ok then we are opening SaveFileDialog Box then User will save the file. That's it simple.

Whatever the windows application whether it is windows forms or wpf application, these dialog controls and their functionality is common. But in WPF applications we can't find these controls available in toolbox.

To add these controls in WPF we have to add namespace System.Windows.Control reference to project and Import the namespace in Corresponding Window or Page.

Important Points Regarding Dialog Controls:

To open a DialogControl we have to Call ShowDialog() method.
Every DialogBox will return a value of type DialogResult, based on this value we have to go further action.
For OpenFileDialog Box and SaveFileDialog Boxes Filter Property available to Filter type of documents to show.

Apart from this PrintPreviewDialog box available to show preview of your document when it available for printing. You can find other controls of Windows Forms Here.

Conclusion:

In this way we can work with or use Dialog Controls in Windows Foms.

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WPF vs Windows Forms what is the difference between windows forms and wpf in properties, methods,events of the control

2013-07-13T08:07:00.000+05:30

WPF Vs Windows Forms

Introduction:

In my previous articles i explained what is wpf and wpf features, Architecture of WPF and Basic shapes and drawings in WPF and Various articles on Asp.Net and OopsConcepts.

Now i will explain differences between WPF and Windows Forms in-terms of their properties, events and methods.

Description:

WPF vs Windows Forms:

As earlier i explained in WPF features, We can say all that features are advantages of wpf over windows forms.

Now see the differences in simple terms:

WPF:

Pros:

Powerfull styling and skinning structure is possible.
Easy to create an own look and feel.
Does support windows forms.
Future technology for developing vista applications.
we can reuse the code.
Highly data binding is possible.
Almost all features of HTML and Flash are available.
Support fixed and flow format documents.

Cons:

Declarative Vs Procedural Code.
Required .Net Framework.
Still in development Phase.
Required Advanced Graphics.

Windows Forms:

Pros:

Extensive documentation found on the internet.
Plenty of examples.
Does support WPF.

Cons:

How long will it be supported( As i read in other sites microsoft stops further developing windows forms from 2.0, It is focusing on WPF).
It requires lot of time and work to have good design.

Differences between Windows Forms and WPF in Properties,Methods,and Events for Control:

In Windows Forms Controls like Button, RadioButton, Label, CheckBox and TextBox have Text Property to provide a caption for them but these controls have 'Content' Property in WPF.

In Windows Forms to provide access key for a control with in that text of the control, the character to use as access key will be prefixed with & symbol but in WPF the character to provide as access key have to be prefixed(_) underscore with in the content property.

In Windows Forms to use the TextBox for accepting the password you have to set password char property for it but in wpf there is no property for textbox and instead you have a separate control available for accepting the password that is PasswordBox.

In Windows Forms applications controls have the Property Font to specify the Font, Font-Size, Font-Style but in WPF the Font property is splitted into multiple properties Font-Size, Font-Family,Font - Stretch, Font Style and Font Weight.

In windows forms background color and foreground color properties are used to specify the background color and foreground color. But in WPF this properties are renamed as Background and Foreground which can be used to change the Background and Foreground colors and also Background and Foreground Images.

Most of the Boolean properties in WPF are prefixed with Is. The property for CheckBox and RadioButton to determine whether or not it is checked 'IsChecked'.

For the CheckBox and RadioButton the default event in Windows Forms is checked-changed, but in WPF checked changed event is not available for CheckBox and RadioButton and Instead of they have two events Checked and UnChecked, that will be raised whenever the RadioButton and CheckBox is checked and Unchecked.

In Windows Forms there are three keyboard events key-down, key-up and key-press but in WPF there are only two keyboard events i.e key Down and Key Up and Key press is not available in WPF.

In Window Forms whenever focus enter into control , Enter event will be raised and whenever focus leaves the control leave event will be raised. but these events were renamed in WPF as gotfocus and lostfocus.

WPF provides a control called TextBlock that is similar to a label, which will not allow to
the text, but all the properties of the TextBlock are similar to a TextBox and not the label.

Conclusion:

These are all the differences in - terms features and properties,methods and events between WPF and Windows Forms.In my next article i will explain What are the layout controls available in WPF.

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