C# 事件，如何引发它们？

Question

我正在尝试学习在 C# 中引发和处理事件。

这是我的简单示例:

///////////////  creating a new BALL object ///    
ballClass ball = new ballClass();

void button1_Click(object sender, EventArgs e)
{
    // this should make the BALL object raise an event
    ball.onHit();
    label1.Text = "EVENT SEND";
}
   
// when event is fired, label text should change
void BallInPlayEvent(object sender, EventArgs e)
{
    label2.Text = "EVENT FOUND!";
}

和球类:

class ballClass
{
    public event EventHandler BallInPlay;
    
    public void onHit()
    {
        this.BallInPlay ///// ??? how should i raise this event?
    }
}

在通话中我不太明白，我该如何引发事件？

Answer 1

public void onHit()
{
   if(BallInPlay != null)
     BallInPlay(this, new EventArgs());
}