优化更新代码，添加界面功能并整合

WPFluent/Controls/MessageBox/MessageBoxButtonClickEventArgs.cs

@@ -0,0 +1,46 @@
+using System.Diagnostics;
+using System.Windows;
+
+namespace WPFluent.Controls;
+
+public class MessageBoxButtonClickEventArgs : RoutedEventArgs
+{
+    private MessageBoxButtonClickDeferral _deferral = null!;
+    private int _deferralCount;
+
+    internal MessageBoxButtonClickEventArgs()
+    {
+    }
+
+    public bool Cancel { get; set; }
+
+    public MessageBoxButtonClickDeferral GetDeferral()
+    {
+        _deferralCount++;
+
+        return new MessageBoxButtonClickDeferral(() =>
+        {
+            DecrementDeferralCount();
+        });
+    }
+
+    internal void SetDeferral(MessageBoxButtonClickDeferral deferral)
+    {
+        _deferral = deferral;
+    }
+
+    internal void DecrementDeferralCount()
+    {
+        Debug.Assert(_deferralCount > 0);
+        _deferralCount--;
+        if (_deferralCount == 0)
+        {
+            _deferral.Complete();
+        }
+    }
+
+    internal void IncrementDeferralCount()
+    {
+        _deferralCount++;
+    }
+}