在C#中创建自定义标签并在事件中传递数据

using System;

[AttributeUsage(AttributeTargets.Method, AllowMultiple = false)]
public class CustomAttribute : Attribute
{
    public string Data { get; set; }

    public CustomAttribute(string data)
    {
        Data = data;
    }
}

public class MyClass
{
    [Custom("Hello, World!")]
    public void MyEventHandler(object sender, EventArgs e)
    {
        // 处理事件
    }
}

public class EventPublisher
{
    public event EventHandler MyEvent;

    public void PublishEvent()
    {
        MyEvent?.Invoke(this, EventArgs.Empty);

        // 获取应用了自定义标签的方法
        var method = typeof(MyClass).GetMethod("MyEventHandler");

        // 获取自定义标签数据
        var attribute = (CustomAttribute)Attribute.GetCustomAttribute(method, typeof(CustomAttribute));
        var data = attribute.Data;

        Console.WriteLine(data); // 输出：Hello, World!
    }
}