1、需要下载 System.Windows.Interactivity.dll  提取码: dc5a 这是微软提供的扩展dll

2、项目引用DLL后，在前端加入代码：

 xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"

3、后台代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Interactivity;
using System.Windows.Media;

namespace WpfStyles
{
    public class RotateBehavior : Behavior<FrameworkElement>
    {
        protected override void OnAttached()
        {
            base.OnAttached();
            this.AssociatedObject.MouseEnter += AssociatedObject_MouseEnter;
            this.AssociatedObject.MouseLeave += AssociatedObject_MouseLeave;
        }

        private void AssociatedObject_MouseLeave(object sender, System.Windows.Input.MouseEventArgs e)
        {
            var element = sender as FrameworkElement;
            element.RenderTransform = null;
        }

        private void AssociatedObject_MouseEnter(object sender, System.Windows.Input.MouseEventArgs e)
        {
            var element = sender as FrameworkElement;
            RotateTransform rotateTransform = new RotateTransform(90, element.ActualWidth/2, element.ActualHeight / 2);
            element.RenderTransform = rotateTransform;
        }

        protected override void OnDetaching()
        {
            base.OnDetaching();
        }
    }
}

4、使用，除了前面提到的引用

 xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"

只需要再加一行代码即可：

 <Button  Content="旋转" Grid.Row="1" Grid.Column="5">
            <i:Interaction.Behaviors>
                <local:RotateBehavior></local:RotateBehavior>
            </i:Interaction.Behaviors>
</Button>