How to start an internationalized WPF-Project in SharpDevelop 4.2?

Question

I want to create a Software, where the User can choose between several Languages.

As a start i want to learn how to handle Internationalization, since i have never done that before.

As IDE i use SharpDevelop or #develop, however you would spell it. I want to use C# and WPF, since i'm also learning XAML/WPF at the moment.

So i create a new WPF-Project in ShardDevelop. On the Main Window i create a ComboBox and a TextBlock.

The ComboBox get's two Entries: "German" and "English". The textBlock should show "Hallo Welt!" or "Hello World!", depending on the Language which is selected.

Now comes the part where i get stuck. I guess each language get's a separate file in XML/XAML-Style (Makes sense). Where are these files and how are they and their Content loaded so that the Text of the selected Language is loaded?

I found several examples but all are something about creating Resource-DLL and using some weird program to decompile them back into a csv-file... i don't get it, isn't there an easier way?

---

I took the next Step. The Text of the TextBlock is now loaded via "{StaticResource Strings.MainForm.hwText}". It looks like this now:

<TextBlock Text="{StaticResource Strings.MainForm.hwText}" />

Also I created one ResourceDictionary for German and one for English which both define the key i used in the TextBlock.

In the Application.Resources Part i load one of the ResourceDictionary's per default.

The Problem now is: How can i "unload" this Dictionary during Runtime and Replace it with the other?

Of course i use the SelectionChange-Event of the ComboBox, but what do i do there?

---

Problem solved!! Thanks to kmatyaszek

Although i changed the Code of the Event-Handler a bit to my needs:

Uri baseUri = new Uri(AppDomain.CurrentDomain.BaseDirectory);
Uri uri = new Uri(baseUri,"Languages\\lang."+((sender as ComboBox).SelectedItem as ComboBoxItem).Tag.ToString()+".xaml");
if(File.Exists(uri.LocalPath) || File.Exists((uri = new Uri(baseUri,"Languages\\lang.de-DE.xaml")).LocalPath)){
    ResourceDictionary dict = new ResourceDictionary();
    dict.Source = uri;
    this.Resources.MergedDictionaries.Add(dict);
}

Answer 1

If you created two ResourceDictionary files you can binding by DynamicResource.

Example:

First resource file (Lang.en-US.xaml):

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:system="clr-namespace:System;assembly=mscorlib">

    <system:String x:Key="Username">Username:</system:String>
    <system:String x:Key="Password">Password:</system:String>
    <system:String x:Key="close">Close</system:String>
    <system:String x:Key="login">Login</system:String>        
</ResourceDictionary>

Second resource file (Lang.pl-PL.xaml):

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:system="clr-namespace:System;assembly=mscorlib">

    <system:String x:Key="Username">Login:</system:String>
    <system:String x:Key="Password">Hasło:</system:String>
    <system:String x:Key="close">Zamknij</system:String>
    <system:String x:Key="login">Zaloguj</system:String>
</ResourceDictionary>

Set default language in Application resources:

 <Application.Resources>
        <ResourceDictionary>
            <ResourceDictionary.MergedDictionaries>
                <ResourceDictionary Source="Lang.en-US.xaml" />
            </ResourceDictionary.MergedDictionaries>
        </ResourceDictionary>
 </Application.Resources>

Let's say that we have ComboBox like below:

<ComboBox Name="cbLang" Margin="2" SelectionChanged="cbLang_SelectionChanged" >
                <ComboBoxItem Content="English" Tag="en-US" />
                <ComboBoxItem Content="Polish" Tag="pl-PL" />
  </ComboBox>

Code-behind SelectionChanged:

 private void cbLang_SelectionChanged(object sender, System.Windows.Controls.SelectionChangedEventArgs e)
        {
            ResourceDictionary dict = new ResourceDictionary();

            switch (((sender as ComboBox).SelectedItem as ComboBoxItem).Tag.ToString())
            {
                case "en-US":
                    dict.Source = new Uri("Lang.en-US.xaml", UriKind.Relative);
                    break;
                case "pl-PL":
                    dict.Source = new Uri("Lang.pl-PL.xaml", UriKind.Relative);
                    break;
                default:
                    break;
            }
            this.Resources.MergedDictionaries.Add(dict);
        }

And you can binding like this:

 <TextBlock Text="{DynamicResource Username}" VerticalAlignment="Center" />