C＃事件系统和对象发送者 [英] C# events system and object sender

问题描述

您好，



我在C＃中遇到了一些事件系统问题。我正在使用类似的代码：

Hello,

I''ve some problems with event system in C#. I''m using code, similar to that:

{
    public delegate void ChangedEventHandler(object sender, EventArgs e);
    class Program
    {
        private static void Main()
        {
            GenEnvent genEvent = new GenEnvent();
            MonitorEvent monEvent = new MonitorEvent(genEvent);
            MonitorEvent monEvent2 = new MonitorEvent(genEvent);
            genEvent.listIt(1);
            Console.ReadLine();
        }
    }
    class GenEnvent
    {
        public event ChangedEventHandler Changed;
        public int i { get; set; }
        protected virtual void OnChange(EventArgs e)
        {
            if (Changed != null)
                Changed(this, e);
        }
        public void listIt(int a) { Console.WriteLine(a); OnChange(EventArgs.Empty); }
    }
    class MonitorEvent
    {
        private GenEnvent genE;
        public MonitorEvent(GenEnvent gene)
        {
            genE = gene;
            gene.Changed += new ChangedEventHandler(workout);
        }
        private void workout(object sender, EventArgs e)
        {
            if (sender == genE)
            {               
                Console.WriteLine("From registered workout {0}", sender.ToString());
            }
        }
    }
}

问题1：我可以投对象发件人到GenEvent？欢迎任何资源链接。

问题2：我如何检查发件人类型？例如：if（sender.GetType == GenEvent）？



谢谢。

Question 1: Can i cast object sender to GenEvent? Any links to resources are welcome.
Question 2: How can i check the sender type? For example something like that: if(sender.GetType == GenEvent)?

Thanks.

推荐答案

//Casting sender to GenEvent
var s = sender as GenEnvent;
if (s != null)
{
    //Do your thing
}

//Check type of sender to be GenEvent
if(sender is GenEnvent)
    Console.WriteLine("From registered workout {0}", sender.ToString());

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