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How to: Create a Custom Translation Provider for the Localization Tool

  • 3 minutes to read

The Localization Tool utilizes the Microsoft Translator as the translation provider. However, one of the notable features of our localization tool is the capability to use custom translation services. That means that you can use alternative translators. In this example, custom translation provider implementation is demonstrated.

To create a custom translation provider, you need to create and register a class, implementing the ITranslatorProvider interface. As an alternative to implementing it from scratch, you can create a descendant of the TranslatorProviderBase class, which already encompasses a good deal of functionality. This class also collects localized values in blocks to shorten the translation based on the online translation services. In this example, we will utilize the second approach.

The TranslatorProviderBase class descendant should implement some methods and properties of the ITranslatorProvider interface, which are not implemented by the base class.

Additionally, overriding the ITranslatorProvider.Translate method is required.

Perform the following steps to implement the translation provider.

  • Add the following class into the platform-agnostic module project (e.g., MySolution.Module), or add a new module to your solution and implement this class in it.

    using DevExpress.ExpressApp.Utils;
    // ...
    public class MyTranslatorProvider : TranslatorProviderBase {
        public MyTranslatorProvider() : base("<br />", 5000) { }
        #region ITranslatorProvider Members
        public override string Caption {
            get { return "My Translate Provider"; }
        public override string Description {
            get { return "My Description"; }
        public override string[] GetLanguages() {
            string[] supportedLanguages = {"en", "fr", "de"};
            return supportedLanguages;
        public override string Translate(string text, string sourceLanguageCode,
            string desinationLanguageCode) {
            string result = "";
            // Place the code that translates 'text' from 'sourceLanguageCode' to 'desinationLanguageCode' here
            return result;

    Pass the maximum block length and separator to the base class constructor.


    You can also override the auxiliary CalculateSentences method if you need to split the localized value into several parts to be localized separately. For instance, this is required when the translator service incorrectly handles special symbols, and also when you need to exclude strings enclosed in quotes and other special symbols. The TranslatorProviderBase class collects localized values, and splits them into small parts based on the CalculateSentences method, and then composes blocks from these smaller parts and processes them with the Translate method.


    To see a complete example, refer to the sources of the built-in BingTranslatorProvider available at C:\Program Files\DevExpress 24.1\Components\Sources\DevExpress.ExpressApp\DevExpress.ExpressApp.Win\Core\ModelEditor\Localization\TranslatorProviders.cs

  • Modify the module’s constructor to register a custom translation provider class.

    public sealed partial class MySolutionModule : ModuleBase {
        public MySolutionModule() {
            TranslatorProvider.RegisterProvider(new MyTranslatorProvider());
  • Rebuild your solution, and this custom translation provider will replace the default provider used by the Localization Tool in Visual Studio and at runtime.
See Also