Add LocalizedString Documentation

docs/TOC.yml

@@ -90,6 +90,8 @@
       href: helpers/weakeventmanagert.md
     - name: "WeakEventManagerExtensions"
       href: helpers/weakeventmanagerextensions.md
+    - name: "LocalizedString"
+      href: helpers/localizedstring.md
 - name: "ObjectModel"
   items:
     - name: "AsyncCommand"

docs/extensions/translateextension.md

@@ -2,13 +2,13 @@
 title: "Xamarin Community Toolkit TranslateExtension"
 author: sthewissen
 ms.author: joverslu
-description: "The TranslateExtension allows users to handle multi-language support at runtime."
+description: "The TranslateExtension allows users to handle multi-language support in XAML at runtime."
 ms.date: 10/09/2020
 ---
 
 # Xamarin Community Toolkit TranslateExtension
 
-The TranslateExtension allows users to handle multi-language support at runtime. It uses the built-in `LocalizationResourceManager` helper to retrieve the correct translation resource for the current active [CultureInfo](xref:System.Globalization.CultureInfo).
+The TranslateExtension allows users to handle multi-language support in XAML at runtime. It uses the built-in `LocalizationResourceManager` helper to retrieve the correct translation resource for the current active [CultureInfo](xref:System.Globalization.CultureInfo).
 
 ## Syntax
 

docs/helpers/localizedstring.md

@@ -0,0 +1,65 @@
+---
+title: "Xamarin Community Toolkit LocalizedString"
+author: maxkoshevoi
+ms.author: v-makkos
+description: "Allows users to handle multi-language support in C# code at runtime."
+ms.date: 2/20/2021
+---
+
+# Xamarin Community Toolkit LocalizedString
+
+The LocalizedString allows users to handle multi-language support in C# code at runtime. It uses the built-in [LocalizationResourceManager](../helpers/localizationresourcemanager.md) helper to react on current active [CultureInfo](xref:System.Globalization.CultureInfo) change.
+
+## Examples
+
+The following property raises `PropertyChanged` event and regenerates string using function provided in constructor, when `LocalizationResourceManager.Current.PropertyChanged` is triggered. 
+As a result page will be updated with the value localized using new culture.
+
+ViewModel:
+```csharp
+public LocalizedString AppVersion { get; } = new(() => string.Format(AppResources.Version, AppInfo.VersionString));
+```
+
+Page:
+```xaml
+<Label Text="{Binding AppVersion.Localized}"/>
+```
+
+Output:
+```
+Version: 1.0.0
+```
+
+> [!NOTE]
+> For this example to work, you also need to update `AppResources.Culture` when `LocalizationResourceManager.Current.CurrentCulture` is changed. 
+> Add this line above `LocalizationResourceManager.Current.Init()` call to do that.
+> ```csharp
+> LocalizationResourceManager.Current.PropertyChanged += (_, _) => AppResources.Culture >= LocalizationResourceManager.Current.CurrentCulture;
+> ```
+
+## Properties
+
+| Property | Type | Description |
+| -- | -- | -- |
+| Localized | string | Returns string localized using current culture. |
+
+## Events
+
+| Events | Description |
+| -- | -- |
+| PropertyChanged | Notifies of culture change. |
+
+## Sample project
+
+[Settings sample page Source](https://github.com/xamarin/XamarinCommunityToolkit/blob/main/samples/XCT.Sample/ViewModels/SettingViewModel.cs)
+
+You can see this element in action in the [Xamarin community toolkit sample app](https://github.com/xamarin/XamarinCommunityToolkit/tree/main/samples/XCT.Sample).
+
+## API
+
+- [LocalizedString](https://github.com/xamarin/XamarinCommunityToolkit/blob/develop/src/CommunityToolkit/Xamarin.CommunityToolkit/Helpers/LocalizedString.shared.cs)
+
+## Related links
+
+- [LocalizationResourceManager](../helpers/localizationresourcemanager.md)
+- [TranslateExtension](../extensions/translateextension.md)