添加项目文件。

Sai.Toolkit.Mvvm/Behaviors/ValidationRuleBehavior.cs

@@ -0,0 +1,45 @@
+using Microsoft.Xaml.Behaviors;
+
+using System.Windows;
+using System.Windows.Controls;
+
+namespace Sai.Toolkit.Mvvm.Behaviors;
+
+/// <summary>
+///     在xaml的资源中声明，viewModel继承IValidationExceptionHandler，通过IsValid判断能否执行
+/// </summary>
+public class ValidationRuleBehavior : Behavior<FrameworkElement>
+{
+	private int errorCount;
+
+	protected override void OnAttached()
+	{
+		base.OnAttached();
+		AssociatedObject.AddHandler(Validation.ErrorEvent, new EventHandler<ValidationErrorEventArgs>(OnValidationError));
+	}
+
+	protected override void OnDetaching()
+	{
+		AssociatedObject.RemoveHandler(Validation.ErrorEvent, new EventHandler<ValidationErrorEventArgs>(OnValidationError));
+	}
+
+	private void OnValidationError(object sender, ValidationErrorEventArgs e)
+	{
+		if (AssociatedObject.DataContext is IValidationExceptionHandler handler)
+		{
+			if (e.OriginalSource is UIElement elem)
+			{
+				if (e.Action == ValidationErrorEventAction.Added)
+				{
+					errorCount++;
+				}
+				else if (e.Action == ValidationErrorEventAction.Removed)
+				{
+					errorCount--;
+				}
+			}
+
+			handler.IsValid = errorCount == 0;
+		}
+	}
+}