Winform自定义控件如何通知另一个Winform自定义控件？

Question

Let's say in a custom control I defined some custom event myEvent. Now when raising event, this event will be captured by the parent form.

How can I capture this event in another custom control which would be on the same parent form ? I'd like the other control to subscribe to the first control event somehow.

Answer 1

I've run into a similar situation a lot when dealing with MVC. The way that I like to handle it is to use a mediator design pattern in the controller.

Basically, you have a class that has a register function and a notify function. The register function takes an object that implements a listener interface and a messageId. It stores these in a dictionary. The notify function takes a messageId for the event that needs to be sent to the listeners and notifies the appropriate ones that the event has occurred.

So maybe something along the lines of

public interface IListener
{
void MessageRaised(int messageId, params object[] arguments);
}

public class Mediator
{
public void Register(IListener listener, int messageId)
{
//... add to dictionary of arrays for each messageId
}

public void NotifyListeners(int messageId, params object[] arguments)
{
//... loop through listeners for the messageId and call the MessageRaised function for each one
}
}

Now normally I have a base controller and it implements a static Mediator object. Then all my other controllers inherit from it. If you are using the code behind and cannot inherit, then you might try using a singleton pattern. .Net static classes are pretty great too since they have a constructor so you could use that as well.

So in your case, I would have the code behind for each control implement IListener and then in the constructor for each one, have something like Mediator.GetInstance().Register(this, Messages.MyEvent). That is kind of a quick and dirty way which can be refactored a bit in the future to make it a bit more reusable.

Some resources from a quick google search

http://www.avajava.com/tutorials/lessons/mediator-pattern.html

http://sourcemaking.com/design_patterns/mediator

Good luck

Answer 2

您可以使用事件处理和代表为和你的接收器控制间接订阅您发送器控制的事件，同时通过控件的父控件，充当多路复用器。

Answer 3

The answer is simple. Declare a method in the second form (the one without the event) with the correct signature and mark it as public.

In the parent form assign the method of the second form to the event of the first.

Answer 4

是的，只需发布​​并引发一个事件并从您的侦听器控件中订阅它即可。