如果我有两个实现协议的视图控制器，如何指定我的第三个控制器的委托者？

Question

I have a protocol to exchange data after it is edited. This protocol is implemented in two different view controllers.

The protocol has a single function called taskEdited that sets a value.

In a third view controller that is is pushed from the first, I have a delegate property in my header file:

@property (weak, nonatomic) id <taskEditProtocol> delegate;

And in the .m file I call the method as follows...

[self.delegate taskEdited:self.taskForEdit];

The result is that the method gets called in the first view controller which in this case is what I want. But how do I specify which controller is the delegate of the third view controller?

Answer 1

You must set the delegate property. Most likely in a prepareForSegue:sender: method.

The view controller that you want to be the delegate needs to have a reference to the third view controller (which it can obtain in prepareForSegue:sender: . And then you simply set the property as you would set any other property on any other object.

Answer 2

You need to manually set it in the moment you create the instance of the third controller. Assuming you instantiate the third controller from the controller you want to be the delegate, it would look like this.-

thirdController.delegate = self;