Antelcat.I18N

Antelcat.I18N provides reactive language support for .NET applications, enabling automatic UI updates when the application culture changes. It is designed for modern .NET UI frameworks and supports automatic resource key generation.

Supported Platforms:

• WPF: Requires WPF 4.0 or higher.
• Avalonia: Requires Avalonia 11.0 or higher.

Key Features:

• Static Usage: Bind to .resx files using auto-generated resource keys.
• Dynamic Usage: Bind to strings received from external sources (like JSON/APIs) via standard Binding.
• Reactive Updates: UI elements update automatically when I18NExtension.Culture is changed or when the underlying data source changes.

You can create complex, formatted strings by combining a template from a .resx file with multiple arguments provided via LanguageBinding or standard Binding.

• I18N.Key: The string template (from .resx) containing placeholders like {0}, {1}.
• LanguageBinding: Provides a key to look up a translation for a specific argument.
• Binding: Provides a raw string value from the DataContext for an argument.

<TextBlock>
    <TextBlock.Text>
        <I18N Key="{x:Static myProject:LangKeys.Current_is}">
            <LanguageBinding Key="{x:Static myProject:LangKeys.Language}"/>
            <Binding Path="Language"/>
        </I18N>
    </TextBlock.Text>
</TextBlock>

When your source text is not defined in .resx files (e.g., it comes from a network API or a database), you can bind directly to the text using the {I18N ...} markup extension.

If the text in your ViewModel matches a key in your .resx translation files, the {I18N} extension will automatically look up the translation. The UI will update whenever either the ViewModel property changes or the application culture changes.

<!-- If 'Message' is a property in your DataContext/ViewModel -->
<TextBlock Text="{I18N {Binding Message}}"/>

To avoid manual string management for .resx files, you can use the ResourceKeysOfAttribute to automatically generate a partial class containing your resource keys. This allows you to use x:Static in XAML to reference keys safely.

1. Apply the [ResourceKeysOf] attribute to a partial class.
2. Pass the type of your generated .resx designer class to the attribute.

Note for Avalonia users: If using Avalonia version 2.0.0 or higher, you must initialize the keys in App.axaml using LangKeys.Your_Provider.Initialize();. WPF users can skip this step.

using Antelcat.I18N.Attributes;

namespace MyProject

// The generated class must be partial
[ResourceKeysOf(typeof(My.Resource.Designer.Type))]
public partial class LangKeys;

You can use I18N to translate strings that are not defined in .resx files but are provided dynamically (e.g., from a JSON API). If the dynamic string matches a key in your .resx translation files, I18N will perform the lookup.

Example Scenario:

1. API returns: {"message": "This is a message"}
2. .resx contains translation for key This is a message: <value>这是一条消息</value>
3. ViewModel has a property Message containing the string.

XAML Binding:

<TextBlock Text="{I18N {Binding Message}}"/>

The text will update automatically whenever the Message property changes or the application culture changes.

Once resource keys are generated, you can bind them to UI elements in XAML using the I18N markup extension combined with x:Static.

If your .resx contains:

<data name="Language" xml:space="preserve">
    <value>Language</value>
</data>

You can bind it in XAML like this:

<TextBlock Text="{I18N {x:Static myProject:LangKeys.Language}}"/>

To trigger a reactive update across the entire application when the language changes, update the I18NExtension.Culture property with a new CultureInfo object.

using System.Windows;
using System.Globalization;

I18NExtension.Culture = new CultureInfo("language code");