Hub of Computer Tricks and Programming

Generic Function to convert string to Enum

2014-05-12T14:40:00.002+05:30

private T GetEnumFromString<T>(string value) { try { T t; t = (T)Enum.Parse(typeof(T), value); return t; } catch (Exception E) { return (T)((object)0); } }

The Heartbleed Bug (CVE-2014-0160)

2014-04-14T13:42:00.001+05:30

Neel Metha from Google Security discovered incorrect memory handling in Open TLS Heartbeat extension. By which attacker can access upto 64K of memory of client or server and can expose Private key and other secret data. Affected users should upgrade to OpenSSL 1.0.1g. Users unable to immediately upgrade can alternatively recompile OpenSSL with -DOPENSSL_NO_HEARTBEATS. For complete

Dock panel like animated buttons in WPF(XAML)

2014-04-13T13:13:00.002+05:30

Like dockpanel buttons(Buttons which grows up as mouse enters on button) in windows, we can have the buttons in WPF without writing any C# or VB code. This can be achieved by using EventTriggers & DoubleAnimations. As mentioned in above image as mouse enters on Recycle Bin icon, it grows up, similar thing can be achieved in wpf, sample XAML is written below. Code: <Grid

Deferred Execution in LINQ

2014-04-11T17:38:00.002+05:30

Deferred Execution of Query class Sample { public int i; public String str; } static void Main(string[] args) { List lst = new List(); lst.Add(new Sample() { i = 1, str = "String1" }); lst.Add(new Sample() { i = 2, str = "String2" }); lst.Add(new Sample() { i = 3, str = "String3" }); lst.Add(new Sample() { i = 4, str = "String4" });

Factory Design pattern

2014-04-09T14:01:00.002+05:30

Factory design pattern provides you an interface creating a single object, but let subclass decide which class to instantiate. This pattern is used most frequently when we are having common functionality with different methods for different objects. In that scenario, we will create an interface with defining common functionality which will be implemented by the classes. A class will be defined

TargetInvocationException was unhandled "Exception has been thrown by the target of an invocation." issue in WPF

2014-04-04T13:01:00.001+05:30

In WPF, most probably the issue occurs when we are accessing null object in the constructor of the code file of the XAML or If you are invoking "PropertyChanged" event without having null check inside the constructor. Example 1: public MainWindow() { InitializeComponent(); &

"if" condition inside Select Clause of LINQ Query.

2014-04-02T15:15:00.002+05:30

In LINQ you can't use "if" statement directly in select clause, but you can achieve this by using ternary operator. Consider you are querying an Array of object & the object internally contains another object. We have to select some field from inner object. But it may be chance that for some cases inner object is null. So to prevent your query from throwing "Object Reference not set to

C# Null-Coalescing Operator (??)

2013-07-23T11:02:00.000+05:30

C# has an operator called Null-Coalescing Operator(??), this operator takes two operands. If left hand side operand is not null then it returns left hand side operand else it returns right hand side operands. It is very effective to assign default value to a variable. This variable can be used with reference type as well as nullable value types. A sample code for the use of this operator is

ERROR: Couldn't Find BOOTMGR while booting BackTrack via Bootable pendrive

2013-07-18T12:38:00.001+05:30

I was trying to boot my machine with Backtrack via bootable pendrive, but unfortunately I got an error by saying Couldn't Find BOOTMGR boot: No need to worry, It has just not found the boot loader. so we will have load that by the command. Just write the following command and it will be start loading boot: /casper/vmlinuz boot=casper initrd=/casper/initrd.gz text splash vga=791

How to declare Hashtable or ArrayList in XAML.

2013-07-01T12:23:00.000+05:30

To declare Hashtable or ArrayList in xaml, we need to include the System.Collection namespaces in XAML by using the below key xmlns:col='clr-namespace:System.Collections;assembly=mscorlib' After declaring the namespace we can use all the class of System.Collection namespace with col: prefix Code to Declare the HashTable in XAML: <col:Hashtable x:Key='hash'&

Change Style of ListBoxItem when we use ItemTemplate in ListBox.

2013-05-02T22:54:00.001+05:30

We will see how can we change background and foreground of any ListBoxItem on MouseOver or on Selection, and for ListBoxItem, ItemTemplate is being used. Consider a ListBox in XAML, in which, ListBoxItem contains multiple Label via ItemTemplate. Now you want the background color and the text color of the Labels to be changed on Mouse Over or on Selection of the Item. To achieve this we can use

What is Process?

2013-04-24T12:34:00.001+05:30

Process: Any program running in computer is a process. So there can be multiple processes running in same computer or there can be single process running. Each and every process will have own flow of control. In sequential execution environment, all the process are executed in sequentially. In multiprocessor environment all the process are switched forth and back. Each

ComboBox in WPF DataGrid's Column Header

2013-01-10T16:00:00.000+05:30

Here, In this article, we are going to discuss, how can we add framework elements in WPF Datagrid's column header. We will add combo box in the header. To add Combobox in the Header of DataGrid we use [GridColumn].Header tag. In the tag we can add any element directly. <tools:DataGridTextColumn.Header> <ComboBox x:Name='txtCbo75P' ItemsSource='{

Create Nested headers in WPF DataGrid

2013-01-09T22:36:00.001+05:30

In WPF many times we may require to render a data grid which contains multilevel headers, for example we have columns FirstName, LastName, Address1, Address2, City, State. Now we have to render a grid in which we have these columns these columns will have group name above the column header. It means there will be another level of header above these. In our case FirstName and LastName will

WPF StringFormat example in Binding

2012-12-22T20:17:00.000+05:30