How to localize Silverlight Applications the smart way

Introduction:
A very common task when developing business applications is to localize them for english, german and other languages. The most common approach is to use ResX files in order to create resource classes which can be used to bind the silverlight controls to. This approach is perfectly described by Sly (that is his nickname). Due to a bug in the resource generator from Microsoft, you always have to change the created resource class from internal to public (look at point 17 on his blog entry), which is very annoying … That’s why I was searching for a better solution to localize silverlight applications – and I think I found a really smart way to do that task.

Silverlight Localization (the smart way):
Step1:
First of all you need a silverlight application;) If you already have one – fine. If not, create a new example application. After that you have to add a new resource file. First of all, add a fallback resource file which can be used as an alternativ, if the string can’t be found in one of the language dependend resource files. After that add a resource file for every language you want to add (and call it like the neutral resource file with the postfix of your designated language).

Step2:
Because we go the smart way, it’s important to disable the code generation. In order to do that, open the neutral resource file with a double click in Visual Studio and switch the Access Modifier to “No code generation”.

Step3:
Now add some string resources to the resources files …

Step4:
Microsoft does not really very much to support the localization task, because by default, the resource files won’t be included in the created XAP file. To include the language depended resources into the XAP file, you have to open the project file (.csproj) in your favored text editor (e.g. Notepad++) and add the languages comma separated to the <SupportedCultures> Tag.

<SupportedCultures>de,en</SupportedCultures>

Step5: (We get it soon)
Now we can implement a new class that reads the resources and returns the localized strings.

public class ApplicationResources : IValueConverter
{
    /// <summary>
    /// The Resource Manager loads the resources out of the executing assembly (and the XAP File where there are embedded)
    /// </summary>
    private static readonly ResourceManager resourceManager =
    new ResourceManager("SilverlightLocalization.Resources.Strings",
    Assembly.GetExecutingAssembly());
    
    /// <summary>
    /// Use this property to specify the culture
    /// </summary>
    private static CultureInfo uiCulture = Thread.CurrentThread.CurrentUICulture;
    public static CultureInfo UiCulture
    {
        get { return uiCulture; }
        set { uiCulture = value; }
    }
    
    /// <summary>
    /// This method returns the localized string of the given resource.
    /// </summary>
    public string Get(string resource)
    {
        return resourceManager.GetString(resource, UiCulture);
    }
    
    #region IValueConverter Members
    
    /// <summary>
    /// This method is used to bind the silverlight component to the resource.
    /// </summary>
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        var reader = (ApplicationResources)value;
        return reader.Get((string)parameter);
    }
    
    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        // ConvertBack is not used, because the Localization is only a One Way binding
        throw new NotImplementedException();
    }
    
    #endregion
}


Step6:
Now we have to publish the ApplicationResources class as a Application Resource in order to use it for our binding. To to this, open the App.xaml and extend the Application.Resources.

<Application.Resources>
<SilverlightLocalization:ApplicationResources x:Key="Localization"/>
</Application.Resources>

Step7 (last step):
Yeahh – we can bind the silverlight components now. Therefore replace the content of the Text attribute of the component to localize with the following generic replacement: {Binding ConverterParameter=Page_label01, Converter={StaticResource Localization}, Source={StaticResource Localization}}

e.g. “Page_label01″ is the name of the label specified for that component within the resource file.

The complete example could look like this:

<TextBlock
FontSize="32"
TextAlignment="Center"
Margin = "0,200,0,0"
Text="{Binding ConverterParameter=Page_label01, Converter={StaticResource Localization}, Source={StaticResource Localization}}"
MouseLeftButtonUp="OnClick"
/>


Advantages of this solution:
First of all, I think this solution is very smart, because you don’t need to update the class modifier from internal to public, everytime you change the resource strings.
A second advantage is, that the XAP file is not as big, as if you would use code generation. Why? Because you simply don’t have to create tons of resource access properties. Every resource is loaded within the ApplicationResource class.

Example:
With the following link you can try a working example: Click me Example Application
And here’s the example source code to download: Smart Silverlight Localization (You have to set SilverlightLocalizationTestPage.aspx as the Start Page)

Hope you enjoy this solution.
Cheers
- Gerhard

---

Possibly related posts: (automatically generated)

• How to extract data from Microsoft Excel XML Files
• Code Project; Tools & Code: Edit String Resources Inside Multiple Resource …
• Using Merged Resource Dictionaries in Silverlight 3 to split resources into…
• Globalizing a webpage in.Net