completed the branch

src/Shared/HandyControl_Shared/Interactivity/Commands/CloseWindowCommand.cs

@@ -0,0 +1,24 @@
+using System;
+using System.Windows;
+using System.Windows.Input;
+
+namespace HandyControl.Interactivity
+{
+    public class CloseWindowCommand : ICommand
+    {
+        public bool CanExecute(object parameter) => true;
+
+        public void Execute(object parameter)
+        {
+            if (parameter is DependencyObject dependencyObject)
+            {
+                if (Window.GetWindow(dependencyObject) is Window window)
+                {
+                    window.Close();
+                }
+            }
+        }
+
+        public event EventHandler CanExecuteChanged;
+    }
+}

src/Shared/HandyControl_Shared/Interactivity/Commands/ControlCommands.cs

@@ -156,5 +156,10 @@ namespace HandyControl.Interactivity
         ///     前置主窗口
         /// </summary>
         public static PushMainWindow2TopCommand PushMainWindow2Top { get; } = new PushMainWindow2TopCommand();
+
+        /// <summary>
+        ///     关闭窗口
+        /// </summary>
+        public static CloseWindowCommand CloseWindow { get; } = new CloseWindowCommand();
     }
 }