How to pass on string parameter to another method through button selector?

Question

I have this below delegate method that receives stickerURLString as input:

- (void)selectedSticker:(NSString *)stickerURLString {
    //...
        [self.stickerPreviewButton addTarget:self action:@selector(sendStickerPreviewButtonPressed:) forControlEvents:UIControlEventTouchUpInside];
    //...
}

And the selector calls this method sendStickerPreviewButtonPressed:

- (void)sendStickerPreviewButtonPressed: (NSString *)stickerURLString {
    [self.delegate InputFunctionView:self sendSticker:stickerURLString];
}

As you can see in order to make this work as expected I have to pass on stickerURLString from selectedSticker method to sendStickerPreviewButtonPressed.

I have tried this:

[self.stickerPreviewButton performSelector:@selector(sendStickerPreviewButtonPressed:) withObject:stickerURLString];

instead of this:

[self.stickerPreviewButton addTarget:self action:@selector(sendStickerPreviewButtonPressed:) forControlEvents:UIControlEventTouchUpInside];

But I got "terminating with uncaught exception of type NSException" error.

So anyone knows how to pass on string parameter to another method through button selector?

Possible duplicate of [Attach parameter to button.addTarget action in Swift](http://stackoverflow.com/questions/24814646/attach-parameter-to-button-addtarget-action-in-swift) — Bista, Sep 22 '16 at 04:37
declare a global variable and assign the value inside your method. — caldera.sac, Sep 22 '16 at 04:47
@AnuradhS yes it seems the way for me to go about using global variable even though I try to avoid that as my code is quite complex. Thanks! — SanitLee, Sep 22 '16 at 08:07

score 1 · Answer 1 · edited May 23 '17 at 12:19

If you are using performSelector to call the function then you can use this variation

(id)performSelector:(SEL)aSelector withObject:(id)object;

Documentation

https://developer.apple.com/reference/objectivec/1418956-nsobject/1418764-performselector

You can also check on this answer where another solution is explained, in my opinion probably more complex but useful

https://stackoverflow.com/a/14161831/1502070

score 0 · Answer 2 · answered Sep 22 '16 at 08:20

For UIControl object function 1st parameter is id type, passes by control itself , you get uibutton object as a parameter in sendStickerPreviewButtonPressed: function which is not convertible to string , So you got an error, You may pass string By extending UIbutton class by your custom class . then Create button of your own class, anr get you custom property form sender button .

     -(void)sendStickerPreviewButtonPressed:(mycustomButton*)sender{
      //sender.myCustomString
}

How to pass on string parameter to another method through button selector?

2 Answers2