WPF运行时切换语言遇阻：无法识别.resx文件中的资源项

Hey there! Let's work through this problem step by step—since you're using that simple localization approach, there are a handful of common misconfigurations that could be stopping your {local:Loc} extension from picking up your resx resources. Here's what to check first:

1. Verify Your Resx File Settings #

This is the most frequent culprit:

• Make sure your resource files (e.g., Resources.resx, Resources.en.resx) have their Build Action set to Embedded Resource (right-click the file → Properties → Build Action).
• Set the Custom Tool to PublicResXFileCodeGenerator (instead of the default ResXFileCodeGenerator). This generates a public class for your resources, which your markup extension needs to access.
• In the resx editor's top-right corner, set the Access Modifier to Public—this ensures the generated resource class isn't internal (which would block the extension from reading it).

2. Double-Check Your LocExtension Implementation #

The code from that article should reference your resource class correctly. For example, if your resx files generate a class named Resources, your extension should look something like this:

public class LocExtension : MarkupExtension
{
    private readonly string _resourceKey;

    public LocExtension(string resourceKey)
    {
        _resourceKey = resourceKey;
    }

    public override object ProvideValue(IServiceProvider serviceProvider)
    {
        // Ensure this uses YOUR resource class (e.g., AppResources if you named it that)
        return Resources.ResourceManager.GetString(_resourceKey, Resources.Culture);
    }
}

If your resource class has a different name (like AppLocalization), update the references here accordingly.

3. Confirm the XAML Namespace Reference #

Your local prefix in {local:Loc menuBtn2} must map to the namespace where your LocExtension lives. For example, if your extension is in MyWpfApp.Localization, add this to your XAML root element:

xmlns:local="clr-namespace:MyWpfApp.Localization"

A typo here won't throw an error, but the extension won't execute properly.

4. Match Resource Key Exactness #

Resx keys are case-sensitive. Double-check that the key in your resx file is exactly menuBtn2 (no capitalization differences like MenuBtn2). Also, make sure the key actually exists in the resx file you're targeting (e.g., your default Resources.resx if you haven't switched cultures yet).

5. Test Resource Access in Code First #

To isolate the issue, try fetching the resource directly in your code-behind:

// Replace Resources with your resource class name
var testValue = Resources.menuBtn2;
// Or using the ResourceManager
var testValueManager = Resources.ResourceManager.GetString("menuBtn2");

If this returns null or the key name, your resx setup is the problem. If it returns the correct value, the issue is in your markup extension or XAML setup.

6. Ensure Runtime Culture Switching Logic Works #

If you're switching cultures at runtime, make sure you're updating the resource class's Culture property correctly, and triggering a UI refresh. For example:

// Switch to English
Resources.Culture = new CultureInfo("en-US");
// Refresh all bindings to update the UI
foreach (Window window in Application.Current.Windows)
{
    var bindingExpression = window.GetBindingExpression(Window.ContentProperty);
    bindingExpression?.UpdateTarget();
}

If you've checked all these and still have trouble, feel free to share your LocExtension code or resx file details—we can dig deeper!

内容的提问来源于stack exchange，提问作者Adri1511