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#Silverlight is not running on Google #Chrome! Why?

2015-08-21T08:00:00.000+05:30

Starting Google Chrome version 42, Google has blocked NPAPI plugins in their browser and as a result, you will not be able to run Silverlight applications in your Chrome browser. So, what to do? There is a quick but temporary solution by which you will be able to re-enable the plugin.

In this blog post today, we are going to detail the process. Do remember that, it’s a temporary solution and won’t work in future release of Google Chrome.

Plugins allow extra features to be added to browsers. For example, you can watch certain types of videos or play a game that’s on a webpage. Silverlight is also a plugin that enables you to run rich web applications built using XAMLs.

In the past, many plugins were developed using an older system called NPAPI. Today fewer sites are using NPAPI plugins and they can sometimes cause security risks on websites. To make browsing with Chrome safer, faster and more stable, Google is stopping support for NPAPI plugins with Chrome version 42. You might also heard that, plugin support is already not available in Microsoft Edge for Windows 10.

As Google stopped using NPAPI plugins, generally Silverlight also stopped working on Chrome browsers starting version 42 and thus when you are browsing Silverlight applications on Chrome, it only says you to download the Silverlight plugin. You might have already tried and reinstall the Silverlight plugin and nothing worked out, but working in Firefox and Internet Explorer.

Though it is by default stopped, but there is a way to re-enable it by tweaking the Chrome settings. Remember that, it’s just a temporary solution if you are facing this issue. From Chrome version 45 and onwards, this temporary solution will not work at all and in that case, you have to use a different browser like IE or Firefox to run Silverlight applications.

To tweak it to run Silverlight applications temporary, open Google Chrome and in the address bar, enter the following URL without the quotes: “chrome://flags/#enable-npapi”. This will open the Chrome’s flags settings page and will directly navigate you to the section where you will easily find the NPAPI settings in the list.

As shown above, click the link that says “Enable”. This will enable the use of NPAPI plugins and as a result the Silverlight plugin. Once you enable this plugin, it will ask you to relaunch the browser. Make sure, you clicked the “Relaunch Now” button as shown below to close and start the browser. This will apply the settings properly.

Now you can observe that the NPAPI plugin has been activated and the link “Enable” became “Disable”. If you want to disable the plugin, you can click that link. But as we are not disabling it, just keep it as-is and proceed next.

Now if you run your Silverlight applications in Google Chrome, it will run but will show you a warning message that says “This site uses a plugin (Silverlight) that will soon be unsupported”, as shown in the below screenshot:

Yes, that’s right. As I said above, Google has stopped using the NPAPI plugin that runs the Silverlight and many other plugins. This is just a trick to temporary enable it. Google has also mentioned that, going forward this will be totally stopped and they targeted to permanently deactivate Silverlight NPAPI plugins from version 45. Till that time, this trick will work.

Hope that, the trick was useful to you to fix the Silverlight loading issue in your Google Chrome. Thanks for visiting my blog and subscribing to my RSS feed and email newsletter to keep yourself updated on the new blog posts. I am available on Twitter, Facebook, Google+ and LinkedIn. Do connect with me.

Solution: Internet Explorer crashes when debugging #Silverlight apps

2014-12-30T08:00:00.000+05:30

Is your Internet Explorer crashing when you are trying to debug your Silverlight application from Visual Studio but runs perfectly when running without debug option set? This might be due to an update that Microsoft pushed recently via Windows Update service.

If you faced the same, this post will guide you to resolve it at the earliest. Continue reading to learn about the trick to resolve this. Share it with your friends. This might help them too.

Recently I faced a critical issue when trying to debug my Silverlight application from Visual Studio. The application was running smooth, if I detach the debugger. I spent almost the entire evening to find out the cause of the issue and finally was able to resolve it. The issue was not related to Visual Studio, Silverlight Plugin, Silverlight Application, Internet Explorer but was due to un update that my system installed two days back.

If you face similar issue after the Windows Update, just go to “Control Panel –> Programs –> View Installed Updates” and search for the following “Security Update for Microsoft Windows” KB patch (KB3013126, KB3008923, KB2978120) and uninstall them one by one. I am not sure which one exactly created the issue but uninstalling all of them worked. Don’t forget to restart your system after the uninstallation process to apply the changes.

Update:

I have further investigated the issue and confirmed that, this problem is only occurring for the KB3008923 update. If you just uninstall the said update and reboot, it will work.

If you find any other alternate to the problem, don’t forget to mention it in the below comment section. I will be happy to highlight them in this post body.

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StorageHelper - For Windows Phone + Silverlight app developers

2014-08-19T15:38:00.000+05:30

Few months ago, I wrote a small helper class for all my Windows Phone Silverlight applications, which helped me a lot to store and retrieve data to and from IsolatedStorageSettings. Thus I thought to share the same with you, in case you find it useful.

Read more to find out the code, which you can use freely. Here the only catch is: it works only with the Silverlight type applications.

The helper class consists of three methods named “StoreSetting”, “GetSetting” and “RemoveSetting”. As the name suggests, the said methods will help you to save, retrieve and delete your data to and from Isolated Storage Settings.

Please find below the complete source code which will work with Windows Phone Silverlight type applications, but I will try to provide another code snippet quite soon to help you work with Universal apps.

namespace KunalChowdhury.Helpers

    using System.IO.IsolatedStorage;

    public class StorageHelper

        public static bool StoreSetting(string key, object value)

            if (IsolatedStorageSettings.ApplicationSettings.Contains(key))

                IsolatedStorageSettings.ApplicationSettings[key] = value;

                return true;

            IsolatedStorageSettings.ApplicationSettings.Add(key, value);

            return true;

        public static T GetSetting<T>(string key, T defaultVal = default(T))

            if (IsolatedStorageSettings.ApplicationSettings.Contains(key))

                return (T)IsolatedStorageSettings.ApplicationSettings[key];

            return defaultVal;

        public static void RemoveSetting(string key)

            if (IsolatedStorageSettings.ApplicationSettings.Contains(key))

                IsolatedStorageSettings.ApplicationSettings.Remove(key);

I hope, this optimized code will help you to better utilize your data in Isolated Storage Settings. Don’t forget to check out my other Windows Phone related articles.

Connect with me over Twitter, Facebook and Google+. Subscribe to my blog’s RSS feed and Email Newsletter to get immediate updates about my posts in your inbox. Happy Coding. Cheers.

How to create an Excel file using Silverlight and C-Sharp?

2014-08-01T08:10:00.002+05:30

Sometime we need to export data as Excel report. This can be a plain Console application or a high end desktop and/or web application. You can of course do this using plugins/add-ons but what if you don’t have permission to use any 3rd party assemblies in your application?

Okay, in this post we are going to discuss this with help of a simple Silverlight & C# application but logic will be same in other platforms/technologies too. Keep reading.

Current days, it’s easy to create Excel file as it can read XML file format and view it as Excel. XML based Excel file uses a template to recognize it as Excel format. The tag “<?mso-application profid="Excel.Sheet"?>” does this thing intelligently. The “Workbook” tag tells it to create a Workbook and the “Worksheet” tag tells it to create a Worksheet. In the worksheet, you can create table using the “Table” tag to represent your data into it.

The “Table” tag consists of few “Row” and “Cell” tags to represent the data in tabular format. Now we just have to create rows and cells specifying proper data type which can be string, number etc. Check out the below code snippet where we are populating the data in a tabular format by using the rows and cells in a StringBuilder object and inserting the same in an Excel Template to create the Excel file. As we are using Silverlight, we are reading the excel file template (Data.txt) from the resource and then replacing the predefined $$ROW_DATA$$ tag with the string from the StringBuilder object.

private void OnExportToExcel(object sender, RoutedEventArgs e)
{
    var tableData = new StringBuilder();
    
    // populate the data in each cell of the rows
    for (var i = 0; i < 5; i++)
    {
        tableData.Append("<Row ss:AutoFitHeight="0">");
        tableData.Append("<Cell><Data ss:Type="String">" + Persons[i].Fname + "</Data></Cell>");
        tableData.Append("<Cell><Data ss:Type="String">" + Persons[i].Lname + "</Data></Cell>");
        tableData.Append("<Cell><Data ss:Type="String">" + Persons[i].City + "</Data></Cell>");
        tableData.Append("<Cell><Data ss:Type="Number">" + Persons[i].Age + "</Data></Cell>");
        tableData.Append("</Row>");
    }
    
    // read the excel file template from the resource
    using (var stream = Application.GetResourceStream(new Uri("/Demo;component/Data.txt", 
                                                                UriKind.Relative)).Stream)
    {    
        using (var streamReader = new StreamReader(stream))
        {
            // read the template and replace the table data to the specific portion of it
            var template = streamReader.ReadToEnd();
            template = template.Replace("$$ROW_DATA$$", tableData.ToString());
    
            SaveFileDialog dialog = new SaveFileDialog();
            dialog.Filter = "Excel File (*.xml)|*.xml";
    
            if (dialog.ShowDialog() == true)
            {
                using (var fileWriter = new StreamWriter(dialog.OpenFile()))
                {
                    // write the data and save it as excel file
                    fileWriter.Write(template);
                }
            }
        }
    }
}

Later save the whole string as a File in local system. As it was Silverlight application, we used SaveFileDialog to create the stream. Remember that, though the demonstration was done using Silverlight and C#, but the implementation is same in all other technologies too. If you understand the Excel File template and it’s above implementation to structure the data, you will not face any issues else where.

Here is the simple Excel file template that we used in this demonstration, but we can further study the Excel file structure to add various other options, settings and styles:

Keeping an article simple, always help the readers to understand it easily and thus this post with a simple demonstration. If you further want to learn about adding styles in Excel sheet that we created, stay tuned to my blog to read the next post. Till then, happy coding.

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Inheritance in XAML Styles

2014-02-14T08:00:00.000+05:30

Style inheritance in XAML? Sounds funny? No. If we have inheritance in classes, CSS styles; then why not in XAML styles? There are many such occasions when we need to copy the same style in multiple templates/styles of a control.

In this post, we will learn how to use a single piece of style and use it in other place to inherit the common styling. If you are using XAMLs excessively, this might be a very good topic for you.

If you are a XAML designer and/or building a lot of controls in XAML, you might have used the common styles in all the control templates in order to provide the similar look & feel across your controls. In OOPs concept we already learnt about inheritance and if you worked on CSS styles, you might have done that too. In XAML also, we can use the same thing to declare a base style and use it in all places where we need it.

It’s not a new thing but I have observed that, many people are unaware of this. Hence, thought to share this trick with you in case if you don’t know or forget about it, this post will help you next time when you need inheritance in your XAML.

To implement this, just create a base style with a Key name and a proper TargetType. Make sure to set both of them properly. Then list down all the common property values using <Setter/> tag as shown in the first code snippet below:

Now when you want to use that base style in a different style (of same TargetType), just call the inheritance by setting the base style using BasedOn attribute. The value of it should be the Key name as a StaticResource as shown in the second code snippet above (highlighted).

That’s it! All the common styles will now inherit to the derived style and you are good to go without copying the same thing again and again. Multiple and Multilevel inheritance are supported in XAML styles. So, keep on using them. Cheers.

In case you have any specific questions related to this topic, drop a line below and I will try to answer you as soon as possible. Also, I am available on Twitter and Facebook. Connect with me there to get my updates. Don’t forget to ask your queries.

Simplest way to Encrypt and Decrypt of data in Windows Phone apps

2014-01-06T21:25:00.000+05:30

Sometime we need to provide an encryption mechanism to protect user data in phone and/or sharing the data over internet to a database. Data security should be always maintain by a developer to protect the content of the application that the user enters.

If you are building an app and looking for some way to implement the mechanism, here is a wrapper class for you to do encryption and decryption of a string literal easily.

Microsoft provides a static class named “ProtectedData” which is part of “System.Security.Cryptography” namespace, provides a way to access the Data Protection API (DPAPI) available in Microsoft Windows 2000 and later operating systems. This also works in Windows Phone operating system. The class exposes two APIs named Protect and Unprotect which can be used to encrypt and decrypt users data such as username, passwords, card information, pins etc.

In one of my app “Password Locker” for Windows Phone, I already used this class to keep every details of user in a strong encrypted format with 256-bit Encryption Key. If you are also building any app and want to use the same API, you can use the following code snippets which is a wrapper above the ProtectedData class to help you easily encrypt and decrypt string literals with your custom private encryption key.

Here is the whole code snippet which you can use but make sure to change the encryption key (a sample provided here) with a strong, unbreakable string combination of letters, numbers and special characters:

namespace KunalChowdhury.Services
{
    using System.Security.Cryptography;
    using System.Text; 
    public static class EncryptionService
    {
        // enter your private encryption key
        // this should be combination of letters, numbers and special characters
        private const string EncryptionKey = "My3ncRYpt10nK3y"; 
        private static byte[] GetToken()
        {
            return Encoding.UTF8.GetBytes(EncryptionKey);
        } 
        public static byte[] Encrypt(string text)
        {
            return ProtectedData.Protect(Encoding.UTF8.GetBytes(text), GetToken());
        } 
        public static string Decrypt(byte[] encrptedText)
        {
            var decryptedBytes = ProtectedData.Unprotect(encrptedText, GetToken());
            return Encoding.UTF8.GetString(decryptedBytes, 0, decryptedBytes.Length);
        }
    }
}

Here the GetToken() method will return you a byte array of your special EncryptionKey which is only known to the application. You just have to pass the plain text to the method Encrypt() to encrypt the string and get a byte array to store in your database. When you want to retrieve it and show it to the user, call the Decrypt() method of the class by passing the encrypted byte array. This will return you the original string literal that the user actually entered.

Implementing this in your application, you and your user will be sure that the data is safe from unauthenticated access and stored in completely encrypted format. You are free to use the above code in your applications. If used, just drop a small line below in the comment section with the name and link of your application.

Thanks for reading this blog. I hope that it will help you in protecting user’s data. Don’t forget to subscribe to my blog and connect with me on Twitter, Facebook to get regular updates. Happy coding. Cheers.

How to set no. of columns in Telerik’s RadDiagramToolbox?

2013-12-23T20:19:00.000+05:30

If you are working on Silverlight and/or WPF project and using Telerik RadControls library, you might be aware of RadDiagram and RadDiagramToolbox. When you add gallery items in RadDiagramToolbox, by default it comes in three columns.

In some business scenario, you might want to increase or decrease the no. of columns in the RadDiagramToolbox. This small blog post will help you in this.

The default three column toolbox eats a big screen space and sometime just an one or two column is more than sufficient to show to the user. The control directly does not exposes any properties or methods to configure the no. of columns to show but you can surely configure it by editing the template of the RadDiagramToolboxGroup. Here is a screenshot of the basic layout:

If you want to modify the column count in your Telerik’s RadDiagramToolbox, just copy the below code in your XAML page and change the column count appropriately (in our case, we set it to 1 “one”). Let’s understand how this has been implemented.

In the RadDiagramToolboxGroup style, create the ItemsPanel template with a RadUniformGrid control which supports setting the no. of columns. Setting Columns=”x” attribute will set “x” nos. of columns in the RadDiagramToolbox control, where “x” is a numeric positive integer.

Here is the XAML of the template for your reference:

<Style TargetType="telerik:RadDiagramToolboxGroup">
    <Setter Property="ItemsPanel">
        <Setter.Value>
            <ItemsPanelTemplate>
                <telerik:RadUniformGrid VerticalAlignment="Top" Columns="1" />
            </ItemsPanelTemplate>
        </Setter.Value>
    </Setter>
</Style>

Here are two screenshots of the same with number of columns set as 2 (two) and 1 (one) respectively:

I hope, this small trick will allow you to configure the columns in your RadDiagramToolbox control. Not only this, you will be now able to reconfigure it dynamically based on user’s input. That’s your business logic.

Thanks for reading this trick. Drop a line below if that helps. Connect with me on Twitter and Facebook to get the updates on articles and technical stuffs. Cheers.

Now grab the Free version of XAML Spy (Express)

2013-11-12T07:00:00.000+05:30

XAML Spy is the visual runtime inspector for Silverlight, WPF, Windows Phone and Windows 8 Store applications which provides direct access to UI visual tree, runtime UI modifications to check/set different properties temporarily, monitor events, extract package contents and much more.

With the release of XAML Spy version 2, the company introduced a light weight Free version for the XAML designers/developers to play with their XAML files. Read more to grab your copy.

Like IE developer toolbar (for HTML/CSS), XAML Spy provides you access to visual tree and/or automation tree of XAML applications where you can modify the properties to check the look in runtime. You can also monitor the events, extract the complete XAML, explore application package content, explore isolated storage, do remote debugging and many other things of your Silverlight, WPF, Windows Phone and Windows 8 Store applications.

Basically, XAML Spy is a commercial application but with the release of version 2 of the product, the company also released a Express version which is Free for the developers and designers with limited functionalities. The product is available as both standalone application and Visual Studio extension.

Comparison Chart

Here is the complete comparison chart of the features of Express Edition (Free) and Commercial version of XAML Spy:

When installing XAML Spy for the first time, you can evaluate the product for a limited period. During the evaluation period you have access to all features of XAML Spy. Once the evaluation period has expired, XAML Spy will automatically switch to the XAML Spy Express edition, unless you purchase a license.

This is really a very good tool for all Silverlight, WPF, Windows Phone and Windows 8 Store application/game developers and designers. If you have not tried it yet, download the free Express Edition now.

WPDev Tips: How to pass an object to WP Navigation Service?

2013-10-29T07:00:00.004+05:30

While working on an application last weekend, I was in need to pass an object as query string parameter to the other page of my Windows Phone application. NavigationService does not allow you to pass any complex object.

Then I found a cool idea by which you will be able to send the whole object to the other page. In this blog post, I am going to share you the trick.

The sealed class NavigationService present under System.Windows.Navigation namespace provides methods and events to support navigation from one page to another inside Silverlight and Windows Phone applications. As the class is Sealed, you can not extend it directly to implement your functionalities.

The Navigate(…) method of NavigationService only takes one parameter of type Uri where you can pass strings as part of query string parameters.This is simple if you are passing few strings as query string parameter value to the other page. But think about a scenario where you have to pass a huge chunks of data or an object. The same happened with me last weekend while building a Windows Phone application and I had to send the whole object to other page.

The workaround to this problem is assigning a static/shared variable or using the Application State to pass value from one page to other. But hold on… do we have any other alternative to that or can Navigation Service itself handle it? To answer your query, I will first say “No, you can not do this with Navigation Service” but secondly “Yes, you can do so”. Huh!!! Isn’t it a contradictory answer of my own reply? Okay, let me clarify what I said here first.

The NavigationService does not allow you to pass a complex object or a complex data type as part of query string parameter. You can not even extend it using inheritance because it is a sealed class. But you can extend the class using an Extension method and do whatever you want to play with it.

Let’s see the extension method to implement our own NavigationService method where we will be able to pass a complex data type to the Navigate(…) method:

Here the first parameter says that, it is an extension method of NavigationService class, the second parameter takes the URI of the page where we want to navigate and the third parameter takes the data object. Here please note that, you don’t have to pass an instance of NavigationService as part of the first parameter because it is an extension method of it. You just have to pass the source and the data.

As stated earlier, call the NavigationService.Navigate(…) method passing the URI of the page and the object that you want to send to the destination page. Here is a sample code snippet for you to visualize it clearly:

Now once you are in the destination page, instead of calling NavigationContext to get the query string parameter value, you can call the GetNavigationData() method which is again an extension method of the class NavigationService. Calling the method will return you the passed object. Here is a code snippet of the same:

As per your requirement, you can keep the data object in NavigationService as long as you want or you can nullify it once you retrieve it. This way you will be able to use the NavigationService and pass objects to second page in a completely cleaner way.

Here is my complete source code of the extension methods of my NavigationService that helped me in many way during my whole application:

public static class Extensions
{
    private static object Data;

    /// <summary>
    /// Navigates to the content specified by uniform resource identifier (URI).
    /// </summary>
    /// <param name="navigationService">The navigation service.</param>
    /// <param name="source">The URI of the content to navigate to.</param>
    /// <param name="data">The data that you need to pass to the other page 
    /// specified in URI.</param>
    public static void Navigate(this NavigationService navigationService, 
                                Uri source, object data)
    {
        Data = data;
        navigationService.Navigate(source);
    }

    /// <summary>
    /// Gets the navigation data passed from the previous page.
    /// </summary>
    /// <param name="service">The service.</param>
    /// <returns>System.Object.</returns>
    public static object GetNavigationData(this NavigationService service)
    {
        return Data;
    }
}

I hope, this will also help you to pass any complex value to a different page in your Silverlight and/or Windows Phone applications. Don’t forget to share your feedback and/or any other alternative that you discovered while building your own applications. In case you have any queries, drop a line to me and I will try to answer you as soon as I can.

Connect with me on Twitter and Facebook to get regular updates on Microsoft technology fronts like Silverlight, Windows Phone, Windows 8 (RT), XAML, C# and Visual Studio. Don’t forget to subscribe to my blog’s RSS feed to get regular updates of articles to your inbox.

How to restrict Telerik RadDiagram within a specific viewport?

2013-10-24T07:15:00.002+05:30

If you are a Silverlight application developer and using Telerik RadDiagram control, you might have seen that you can zoom and pan the diagram control and move it to any boundary. In some scenarios, we need to restrict it to a positive quadrant.

In such case, based on your business logic, you have to restrict the diagram to some quadrant value. In this small post, we will learn how to set it’s viewport to a specific bounds.

Have a look into the above screenshot of the RadDiagram control. This is the default behaviour and thus you will be able to place the shapes in any quadrant location. It’s good to see such functionality in-built into the control but as per business logic, you might want to restrict the shape or the diagram control itself from the location which is in negative quadrant.

Unfortunately, the RadDiagram does not expose mechanism allowing users to restrict the viewport of the control to go negative out of the box. However, there is an easy way to achieve this requirement. You can subscribe to the ViewportChanged event of the RadDiagram and use the native BringIntoView() method. If you detect that the viewport will visualize negative values you can bring the (0, 0) point of the RadDiagram into the current view port. By doing this you will restrict the users to pan or zoom the diagram so that the rulers will visualize negative values.

To demonstrate it, let’s have a grid with the RadDiagram and two RadDiagramRulers. By default when all the bindings are proper, you can easily check how you can move the diagram content to a negative value.

<Grid>
    <Grid.RowDefinitions>
        <RowDefinition Height="20" />
        <RowDefinition Height="*" />
    </Grid.RowDefinitions>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="20"/>
        <ColumnDefinition Width="*"/>
    </Grid.ColumnDefinitions>
    <telerik:RadDiagramRuler Diagram="{Binding ElementName=diagram}" 
                             Placement="Top" Grid.Column="1"/>
    <telerik:RadDiagramRuler Diagram="{Binding ElementName=diagram}" 
                             Placement="Left" Grid.Row="1"/>
    <telerik:RadDiagram x:Name="diagram"
                        Grid.Row="1"
                        Grid.Column="1"
                        ScrollViewer.HorizontalScrollBarVisibility="Visible"
                        ScrollViewer.VerticalScrollBarVisibility="Visible"
                        IsZoomEnabled="False"
                        Width="1024" Height="768"
                        ViewportChanged="OnDiagramViewportChanged">
        <telerik:RadDiagramShape Content="Shape 1" Position="20,20" />
    </telerik:RadDiagram>
</Grid>

Now to fix the issue with a viewport boundary, subscribe to the ViewportChanged event and write your own logic (in our case, we are going to restrict it to positive quadrant) as shown below:

private void OnDiagramViewportChanged(object sender, PropertyEventArgs<Rect> e)
{
    if (e.NewValue.Top < 0 || e.NewValue.Left < 0)
    {
        diagram.BringIntoView(new Rect(0, 0, e.NewValue.Width, e.NewValue.Height), false);
    }
}

And that’s it. You will not be able to drag and move your diagram canvas outside that boundary. I hope, this solution will give you an idea about track and restrict the viewport of Telerik RadDiagram control. Enjoy.