简单的自定义事件

这是创建自定义事件并引发它们的简便方法。您将在抛出的类中创建一个委托和一个事件。然后从代码的另一部分订阅该事件。您已经有一个自定义事件参数类，因此可以在此基础上构建其他事件参数类。注意：我尚未编译此代码。

public partial class Form1 : Form{    private TestClass _testClass;    public Form1()    {        InitializeComponent();        _testClass = new TestClass();        _testClass.onUpdateStatus += new TestClass.StatusUpdateHandler(UpdateStatus);    }    private void UpdateStatus(object sender, ProgressEventArgs e)    {        SetStatus(e.Status);    }    private void SetStatus(string status)    {        label1.Text = status;    }    private void button1_Click_1(object sender, EventArgs e)    {         TestClass.Func();    }}public class TestClass{    public delegate void StatusUpdateHandler(object sender, ProgressEventArgs e);    public event StatusUpdateHandler OnUpdateStatus;    public static void Func()    {        //time consuming pre        UpdateStatus(status);        // time consuming pre        UpdateStatus(status);    }    private void UpdateStatus(string status)    {        // Make sure someone is listening to event        if (onUpdateStatus == null) return;        ProgressEventArgs args = new ProgressEventArgs(status);        onUpdateStatus(this, args);    }}public class ProgressEventArgs : EventArgs{    public string Status { get; private set; }    public ProgressEventArgs(string status)    {        Status = status;    }}