1、安装NuGet

        

2、在XAML的命名空间引入：

xmlns:i="http://schemas.microsoft.com/xaml/behaviors"

3、使用：

<Canvas Background="Aqua">
    <Rectangle Stroke="Red" 
               Width="{Binding RectModel.RectangleWidth}" 
               Height="{Binding RectModel.RectangleHeight}" 
               Canvas.Left="{Binding RectModel.RectangleLeft}" 
               Canvas.Top="{Binding RectModel.RectangleTop}"/>
    <i:Interaction.Triggers>
        <!--EventName是Command指定的Action-->
        <i:EventTrigger EventName="MouseDown">
            <i:InvokeCommandAction Command="{Binding MouseDownCommand}"/>
        </i:EventTrigger>
    </i:Interaction.Triggers>
</Canvas>

        --我这里的ViewModel部分是这样子的

public SimpleCommand MouseDownCommand { get; private set; }   
// 构造方法中初始化
MouseDownCommand = new SimpleCommand { DoExecute = new Action<object>(MouseDown) };


/// <summary>
/// 鼠标按下的命令执行逻辑
/// </summary>
/// <param name="obj"></param>
/// <exception cref="NotImplementedException"></exception>
private void MouseDown(object obj)
{
    Debug.WriteLine("触发Canvas的MouseDown命令");
}


/// SimpleCommand类是这样的：
public class SimpleCommand : ICommand
{
    public event EventHandler CanExecuteChanged;
    public Action<object> DoExecute { get; set; }

    public bool CanExecute(object parameter)
    {
        return true;
    }

    public void Execute(object parameter)
    {
        if (DoExecute != null)
        {
            DoExecute(parameter);
        }
    }
}

4、这样就可以在ViewModel中直接给这个Command内容了，不用像之前那么麻烦地绑定Command了，这样更加清晰，Command也可以有花样地组合