Localizing a WPF application with resource files

I am localizing a WPF application that consists of a main application project as well as several separate DLL projects that provides the application with general user controls, model classes etc.

Many of the tutorials I’ve found suggested using the App.xaml file to localize the application. This does not work for me, since I must be able to localize all parts of the application, as well as the separate DLLs.

Luckily, it’s really easy to get resource file-based localization up and running for an WPF app. Just follow the steps below and keep in mind that the names that I use are only boring suggestions. You can go as wild as you want.

Step 1. Create a WPF application

First, let’s create a new WPF application. I call mine… … …HelloWorld!

As you can see, I have also added a button that we are going to localize.

Step 2. Create the resource file

Now, let’s add a resource file to which we will add textual content. To separate resource files from the rest of the application, I place the file in a Resources folder and name it AppLanguage.resx.

In the image above, you can see a resource file with (so far) a single parameter.

In order to access the resource file from XAML, we have to make the file public:

Once this is done, let’s proceed by accessing the resource file from XAML.

Step 3. Access the resource file content from XAML

Now, let’s use the resource file parameter in our XAML file. Connect the context class to the XAML code by adding the following line into the Window tag:

xmlns:Resources="clr-namespace:HelloWorld.Resources"

After that, you can access the resource parameter as such:

<Button Content="{x:Static Resources:AppLanguage.Menu_LoadData_All}"></Button>

Voilá! The text is finally displayed within the button:

Since we now use a resource file instead of App.xaml, we can use the same file to translate textual content code-behind as well.

Step 4. Access the resource content file from code

To access resource file content from code, simply call the AppLanguage class as such:

using HelloWorld.Resources; //Add this topmost among the using directives
MessageBox.Show(AppLanguage.ButtonText);   //Add this code inside the MainWindow() ctor

When we now start our application, the message box is displayed just like we want: