LangRX

Dynamic localization library for WPF applications based on .resx files with runtime language switching support. No restart, no window recreation.

Highlights

• No code tied to resources: your XAML just uses {DynamicResource KeyName}, like a normal ResourceDictionary.
• Plays well with the designer: the dictionary auto-discovers the app's ResourceManager, so it also works in the XAML editor without running the app.
• No extra dependencies: plain WPF.

Install

dotnet add package LangRX

Prerequisites

• .NET Framework 4.8 or .NET 8.0-windows+, WPF.
• Resource Files: .resx files configured with Visual Studio's default generator (ResXFileCodeGenerator), ensuring that the Properties.Resources class is available in the project.

Quick Start

1. Register the dictionary in App.xaml:

<Application xmlns:lang="clr-namespace:LangRX;assembly=LangRX"
             StartupUri="MainWindow.xaml">
    <Application.Resources>
        <ResourceDictionary>
            <ResourceDictionary.MergedDictionaries>
                <lang:LangRXDictionary />
            </ResourceDictionary.MergedDictionaries>
        </ResourceDictionary>
    </Application.Resources>
</Application>

Note: If the XAML designer doesn't show the texts, pass the resources type explicitly:

xmlns:props="clr-namespace:MyApp.Properties">

<lang:LangRXDictionary ResourceType="{x:Type props:Resources}" />

2. Point it at your resources in App.xaml.cs:

public App()
{
    LangRXDictionary.Initialize(MyApp.Properties.Resources.ResourceManager);
}

3. Bind strings in XAML:

<TextBlock Text="{DynamicResource Greeting}" />
<Button Content="{DynamicResource ButtonChange}" />

4. Switch language:

Every control bound with DynamicResource repaints immediately.

LangRXDictionary.SetLanguage("en-US");   // or "es-ES"

API

Member	Description
Initialize(ResourceManager)	Sets the ResourceManager to populate the dictionary from.
SetLanguage(string)	Switch culture by code (e.g. "en-US") and reload.
SetLanguage(CultureInfo)	Same, from a CultureInfo.

SetLanguage also sets CurrentCulture/CurrentUICulture. Culture fallback follows the resx rules (e.g. en-US → en → neutral).

Demo

A runnable example lives in LangRXDemo: a button that toggles between en-US and es-ES using the neutral Resources.resx and satellite Resources.es.resx.

License

MIT — Copyright (c) 2026 Bracozs