UIResponder的繁琐复制方法

Question

I am swizzling Copy: and Paste: method of UIResponder. I have to write the copied content to a private pasteboard.

- (void)copyToPrivatePasteboard:(id)sender
{
    UIPasteboard *privatePasteboard = [self getPrivatePasteboard];
    [privatePasteboard setString:@""];//How to get the copied string to store in pasteboard.
}

How can i write copied string to pasteboard. The parameter i am getting is of type id. If i convert it to NSString, it won't be proper because it is the sender who is calling this method (UIMenuController).

Answer 1

If I understand you correct, you want to replace UIResponder's -copy: with the code in you Q. (And doing the same thing with -paste: .)

This is the answer to your Q. But there are some comments at the end:

• If you swizzle a method, self will point to the receiver of the message. In your case it is the instance of UIResponder . So you have to grab the data using self . How can you do this? Not in general, because:

• -copy: can contain more than "Put my data to the pasteboard." It is a method. The code there can deal with other things you cannot not know. So you cannot substitute it that easy.

• Because of this -copy: is typically overwritten in subclasses. (I think, that it does nothing in its UIResponder implementation.) Swizzling -copy: in UIResponder will not change any behaviour in an instance of a subclass. Are you familiar with the concept of the responder chain ?

Probably there are better ways to accomplish your goal:

• If you really want to do some swizzling, because it is cool, I would prefer +generalPasteboard ( UIPasteboard ).

• Butmaybe you should describe your final goal with more details. Probably there is a completly different way to reach it.