C# 添加对象(类似于委托(delegate))

Question

我想问一下，你能做类似这样的事情吗？

Event += eventInstance;

事件是一个类

我想做一些类似于委托(delegate)的事情:

Write write1 = new Write(() => Console.WriteLine("Write1"));
Write write2 = new Write(() => Console.WriteLine("Write2"));
Write write3 = new Write(() => Console.WriteLine("Write3"));

Write write = write1 + write2 + write3;
write();

谢谢。

Answer 1

重载 + operator并合并委托(delegate)。像这样:

public class Write
{
    private readonly Action _act;

    public Write(Action act)
    {
        _act = act;
    }

    public void Invoke()
    {
        _act();
    }

    public static Write operator +(Write left, Write right)
    {
        //Do appropriate null-checking.
        var del = (Action)Delegate.Combine(left._act, right._act);
        return new Write(del);
    }
}

像这样使用它:

Write write1 = new Write(() => Console.WriteLine("Write1"));
Write write2 = new Write(() => Console.WriteLine("Write2"));
Write write3 = new Write(() => Console.WriteLine("Write3"));

Write writeall = write1 + write2 + write3;
writeall.Invoke();

将打印

Write1Write2Write3