Localization

When you limit your product's availability to only one language, you limit your potential customer base to a fraction of the world population. If you want your application to reach a global audience, cost-effective localization of your product is one of the best and most economical ways to reach more customers.

Localization is the translation of application resources into localized versions for the specific cultures that the application supports.

The built-in localization mechanism in Silverlight allows you to localize any string resource used by a standard RadControl. Once translated you might use your resources in your Silverlight project without changing anything.Common_Localization_070

The purpose of this tutorial is to show you how to localize any resource string used by a RadControl.

All examples in this tutorial are demonstrated in the context of the Telerik RadGridView control. However, the techniques and principles used for the localization of the string resources are valid for all the other Telerik Silverlight controls.

This topic contains the following sections:

What is LocalizationManager?

The Telerik.Windows.Controls.LocalizationManager allows you to easily localize any of the Telerik controls.

To apply custom localization to your controls just instantiate your custom LocalizationManager and set it to the static property LocalizationManager.Manager, before the creation of the UI.

C#

LocalizationManager.Manager = new CustomLocalizationManager();

VB.NET

LocalizationManager.Manager = New CustomLocalizationManager()

Note that you have to set the localization manager before the creation of the UI, otherwise some parts might remain not-localized.

Resource Keys

Some of the controls are complex user interface controls (e.g. RadGridView, RadScheduleView) and their strings for localization are numerous. In order to be able to distinguish these resources, an unique identifier called resource key, is assigned to each localizable string.

On the picture below you can see some resource keys and the strings they are associated with.  
Common_Localization_060

For a full list of Resource Keys, check out the Localization topic for the specific control.

Localization Using Built-in Resources

The built-in localization mechanism in Silverlight provides the possibility to set the used Telerik Silverlight controls in one of the following supported languages:

  • English

  • German

  • Spanish

  • French

  • Italian

  • Dutch

  • Turkish

They are located in separate files (each for every language). You can find them in the corresponding folders together with the other binaries in your local installation.

Not all the controls support each of those languages.

Note that, the resource folders are supposed to be placed along with the binaries you have referenced.
Common Localization 050

Firstly, you must defined your preferred language in the tag, like so:

XAML

<SupportedCultures>en;nl</SupportedCultures>

The next step for defining the language settings of the application is changing the Current Culture of the application.

C#

private void Application_Startup(object sender, StartupEventArgs e)
{
    Thread.CurrentThread.CurrentCulture = new CultureInfo("es");
    Thread.CurrentThread.CurrentUICulture = new CultureInfo("es");

    this.RootVisual = new MainPage();
}

VB.NET

Private Sub Application_Startup(sender As Object, e As StartupEventArgs)
    Thread.CurrentThread.CurrentCulture = New CultureInfo("es")
    Thread.CurrentThread.CurrentUICulture = New CultureInfo("es")

    Me.RootVisual = New MainPage()
End Sub

You could check this help article, where you can find detailed explanation about how to achieve this.

If you want to translate your RadControl in another language, you should use the Custom Localization Manager.

Localization Using ResourceManager

You can base your localization on the standard resource files provided by the .NET framework. For that purpose you will have to create a separate .ResX file for each one of the languages that your application will support.

Imagine that you want to translate your control (for example: RadGridView control) into English, German and Dutch. For that purpose you will have to add three new resource files to your project:

  • GridViewResources.resx - this resource file will store the English(default) resources for the grid control. Set the AccessModifier property to Public.

  • GridViewResources.de.resx - this resource file will store the German resources for the grid control. Set the AccessModifier property to No code generation.

  • GridViewResources.nl.resx - this resource file will store the Dutch resources for the grid control. Set the AccessModifier property to No code generation.

Common Localization 030

Now, having the needed files, it's time to illustrate the idea and localize only the text for the group panel. For that purpose you need to create a single resource string in each one of the three resource files and translate it to the appropriate language.

Note that the name of the resource string should be the same as the resource key for the string that you are localizing. The resource key for the group panel is GridViewGroupPanelText.

For a full list of Resource Keys, check out the Localization topic for the specific control.

The snapshot below shows the content of the GridViewResources.de.resx file. The resource name of the other two files should be the same. The Value column will contain the translation for the appropriate language.
Common Localization 040

The last step is to instantiate the LocalizationManager class and set its ResourceManager to the resources that have been just created (you can do this in the default constructor of the Application class)

C#

LocalizationManager.Manager = new LocalizationManager()
{
   ResourceManager = GridViewResources.ResourceManager
};

VB.NET

LocalizationManager.Manager = New LocalizationManager()
LocalizationManager.Manager.ResourceManager = GridViewResources.ResourceManager

If you rely on culture settings to load the right resources automatically, you have to write some code inside your application's project file. For example, if you have to support English and Dutch languages, you can store the localized strings in Resources.resx and Resources.nl.resx files. For the Resources.resx file you can set ResXFileCodeGenerator to Internal or Public and for others - to No code generation. Then, open the project file in a text-mode and insert the code below into the section. In this way you notify the framework about the supported cultures.

XAML

<SupportedCultures>en;nl</SupportedCultures>

Localization Using Custom Localization Manager

The other way to localize your RadControl is to create a class that derives from the LocalizationManager object and to override its method GetStringOverride(). The logic is pretty simple, you just have to create a switch statement and return the correct translation for each resource key, as it is shown below:

C#

public class CustomLocalizationManager : LocalizationManager
{
  public override string GetStringOverride( string key )
  {
      switch( key )
      {
          case "GridViewGroupPanelText":
              return "Zum gruppieren ziehen Sie den Spaltenkopf in diesen Bereich.";
          //---------------------- RadGridView Filter Dropdown items texts:
          case "GridViewClearFilter":
              return "Filter löschen";
          case "GridViewFilterShowRowsWithValueThat":
              return "Anzeigen der Werte mit Bedingung:";
          case "GridViewFilterSelectAll":
              return "Alles anzeigen";
          case "GridViewFilterContains":
              return "Enthält";
          case "GridViewFilterEndsWith":
              return "Endet mit";
          case "GridViewFilterIsContainedIn":
              return "Enthalten in";
          case "GridViewFilterIsEqualTo":
              return "Gleich";
          case "GridViewFilterIsGreaterThan":
              return "Grösser als ";
          case "GridViewFilterIsGreaterThanOrEqualTo":
              return "Grösser oder gleich";
          case "GridViewFilterIsLessThan":
              return "Kleiner als";
          case "GridViewFilterIsLessThanOrEqualTo":
              return "Kleiner oder gleich";
          case "GridViewFilterIsNotEqualTo":
              return "Ungleich";
          case "GridViewFilterStartsWith":
              return "Beginnt mit";
          case "GridViewFilterAnd":
              return "Und";
          case "GridViewFilter":
              return "Filter";
      }
      return base.GetStringOverride( key );
  }

VB.NET

Public Class CustomLocalizationManager
 Inherits LocalizationManager
 Public Overrides Function GetStringOverride(key As String) As String
  Select Case key
   Case "GridViewGroupPanelText"
    Return "Zum gruppieren ziehen Sie den Spaltenkopf in diesen Bereich."
   '---------------------- RadGridView Filter Dropdown items texts:'
   Case "GridViewClearFilter"
    Return "Filter löschen"
   Case "GridViewFilterShowRowsWithValueThat"
    Return "Anzeigen der Werte mit Bedingung:"
   Case "GridViewFilterSelectAll"
    Return "Alles anzeigen"
   Case "GridViewFilterContains"
    Return "Enthält"
   Case "GridViewFilterEndsWith"
    Return "Endet mit"
   Case "GridViewFilterIsContainedIn"
    Return "Enthalten in"
   Case "GridViewFilterIsEqualTo"
    Return "Gleich"
   Case "GridViewFilterIsGreaterThan"
    Return "Grösser als "
   Case "GridViewFilterIsGreaterThanOrEqualTo"
    Return "Grösser oder gleich"
   Case "GridViewFilterIsLessThan"
    Return "Kleiner als"
   Case "GridViewFilterIsLessThanOrEqualTo"
    Return "Kleiner oder gleich"
   Case "GridViewFilterIsNotEqualTo"
    Return "Ungleich"
   Case "GridViewFilterStartsWith"
    Return "Beginnt mit"
   Case "GridViewFilterAnd"
    Return "Und"
   Case "GridViewFilter"
    Return "Filter"
  End Select
  Return MyBase.GetStringOverride(key)
 End Function
End Class

Of course, if you don't want to hard-code your translation inside your source code, you can always use resource files:

C#

public override string GetStringOverride( string key )
{
   switch( key )
   {
       //----------------------
       case "GridViewClearFilter":
           return GridViewResources.GridViewClearFilter;
       //----------------------
   }
   return base.GetStringOverride( key );
}

VB.NET

Public Overloads Overrides Function GetStringOverride(ByVal key As String) As String
    Select Case key
        '----------------------'
        Case "GridViewClearFilter"
            Return GridViewResources.GridViewClearFilter
        '----------------------'
    End Select
    Return MyBase.GetStringOverride(key)
End Function

See Also