C# 触发另一个类的事件时通知

我有

class A
{
    B b;

    //call this Method when b.Button_click or b.someMethod is launched
    private void MyMethod()
    {            
    }

    ??
}

Class B
{
    //here i.e. a button is pressed and in Class A 
    //i want to call also MyMethod() in Class A after the button is pressed 
    private void Button_Click(object o, EventArgs s)
    {
         SomeMethod();
    }

    public void SomeMethod()
    {           
    }

    ??
}

类A有一个类B的实例

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如何做到这一点？

看一下从B类中删除事件

看看

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您需要在“B”类上声明一个公共事件，并让“a”类订阅该事件：

大概是这样的：

class B
{
    //A public event for listeners to subscribe to
    public event EventHandler SomethingHappened;

    private void Button_Click(object o, EventArgs s)
    {
        //Fire the event - notifying all subscribers
        if(SomethingHappened != null)
            SomethingHappened(this, null);
    }
....

class A
{
    //Where B is used - subscribe to it's public event
    public A()
    {
        B objectToSubscribeTo = new B();
        objectToSubscribeTo.SomethingHappened += HandleSomethingHappening;
    }

    public void HandleSomethingHappening(object sender, EventArgs e)
    {
        //Do something here
    }

....

您需要三件事（在代码中用注释标记）：

B类申报

发生事件时在类B中引发事件（在您的示例中，是-按钮\单击事件处理程序已执行）。请记住，您需要验证是否存在任何订户。否则，您将在引发事件时获得NullReferenceException

订阅类B的事件。您需要有类B的实例，即使您想要订阅（另一个选项-静态事件，但这些事件将由类B的所有实例引发）

代码：

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Thx伙计们，所有答案+1到allDunno为什么要搜索一个C#event示例如此清晰和简单，只是为了交流两个类？经过几个小时的搜索终于。。。我想哭，非常感谢。@Konayuki:非常同意。我一直在寻找一个简单的例子，就是这样。（at）DaveBish：干得好——简单有效。

class A
{
    B b;

    public A(B b)
    {
        this.b = b;
        // subscribe to event
        b.SomethingHappened += MyMethod;
    }

    private void MyMethod() { }
}

class B
{
    // declare event
    public event Action SomethingHappened;

    private void Button_Click(object o, EventArgs s)
    {
         // raise event
         if (SomethingHappened != null)
             SomethingHappened();

         SomeMethod();
    }

    public void SomeMethod() { }
}