C＃观察者的超简单的例子/观察到与代表 [英] Super-simple example of C# observer/observable with delegates

问题描述

最近，我开始挖掘到C＃，但我不能用我的生命弄清楚如何落实代表在语言观察者/可观察模式时工作。

I recently started digging into C# but I can't by my life figure out how delegates work when implementing the observer/observable pattern in the language.

可能有人给我它是如何做一个超级简单的例子？我的有无的GOOGLE了这一点，但所有我发现的例子是不是太问题的具体或过于臃肿。

Could someone give me a super-simple example of how it is done? I have googled this, but all of the examples I found were either too problem-specific or too "bloated".

推荐答案

观察者模式通常与事件实现

下面是一个例子：

using System;

class Observable
{
    public event EventHandler SomethingHappened;

    public void DoSomething()
    {
        EventHandler handler = SomethingHappened;
        if (handler != null)
        {
            handler(this, EventArgs.Empty);
        }
    }
}

class Observer
{
    public void HandleEvent(object sender, EventArgs args)
    {
        Console.WriteLine("Something happened to " + sender);
    }
}

class Test
{
    static void Main()
    {
        Observable observable = new Observable();
        Observer observer = new Observer();
        observable.SomethingHappened += observer.HandleEvent;

        observable.DoSomething();
    }
}

请参阅链接的文章有更详细。

See the linked article for a lot more detail.

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