创建一个事件来监视变量的变化 [英] Create an event to watch for a change of variable

问题描述

让我们只想说，我有：

public Boolean booleanValue;

public bool someMethod(string value)
{
   // Do some work in here.
   return booleanValue = true;
}

如何创建一个事件处理程序会调用时的booleanValue发生了变化？这可能吗？

How can I create an event handler that fires up when the booleanValue has changed? Is it possible?

推荐答案

避免使用公共领域的一般规则。尽量保持他们私人的东西，你可以。然后，你可以使用一个包装物业射击您的活动。见例如：

Avoid using public fields as a rule in general. Try to keep them private as much as you can. Then, you can use a wrapper property firing your event. See the example:

class Foo
{
    Boolean _booleanValue;

    public bool BooleanValue
    {
        get { return _booleanValue; }
        set
        {
            _booleanValue = value;
            if (ValueChanged != null) ValueChanged(value);
        }
    }

    public event ValueChangedEventHandler ValueChanged;
}

delegate void ValueChangedEventHandler(bool value);

这是一个简单的，本土的方式来实现你所需要的。还有其他的方法，即使是由.NET Framework提供的，但上面的方法仅仅是一个例子。

That is one simple, "native" way to achieve what you need. There are other ways, even offered by the .NET Framework, but the above approach is just an example.

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