Completed Blazor UI Current User document.

docs/en/UI/Blazor/CurrentUser.md

@@ -1,3 +1,22 @@
-# Blazor UI: Authentication
+# Blazor UI: Current User
+
+`ICurrentUser` service is used to obtain information about the currently authenticated user. Inject the `ICurrentUser` into any component/page and use its properties and methods.
+
+**Example: Show username & email on a page**
+
+````csharp
+@page "/"
+@using Volo.Abp.Users
+@inject ICurrentUser CurrentUser
+@if (CurrentUser.IsAuthenticated)
+{
+    <p>Welcome @CurrentUser.UserName</p>
+}
+````
+
+> If you (directly or indirectly) derived your component from the `AbpComponentBase`, you can directly use the base `CurrentUser` property.
+
+`ICurrentUser` provides `Id`, `Name`, `SurName`, `Email`, `Roles` and some other properties.
+
+> See the [Server Side Current User](../../CurrentUser) service for more information.
 
-TODO