Which button was tapped... iPhone and Obj-C question

Question

I'm a newbie just begun with iPhone and Obj-C for a month now.

I have two buttons, both of them call the same function as follows

[play addTarget:self action:@selector(showQstn:) forControlEvents:UIControlEventTouchUpInside];

Inside the function showQstn, I want to know what button was tapped. Any idea? Alternate ideas are welcome too.

TIA

Answer 1

You get the clicked button as the argument to your IBAction method showQstn:. You might consider setting the tag on the buttons, then using [sender tag] to identify which one triggered the IBAction method.

Answer 2

Assuming that showQstn: is declared as

-(void) showQstn:(id)sender;

The argument sender is the trigger object of the event.

EDIT: You can also distinguish between the buttons using the tag property. Each view has a unique tag identifier (which can be set programatically or through Interface Builder).

EDIT: UIButton does not have a title property, hence you getting the error. It has a titleForState:. So you should change your code to the following:

NSString *title = [sender titleForState:UIControlStateNormal];
if ([title isEqualToString:@"PLAY!"]) {
  name.text = title;
}

Answer 3

thanks for your replies. I'm still unable to make it work. My code is given below.

    if( [[sender title] isEqual:@"PLAY!"] ){
 qstn = [sender title];
 name.text = qstn;
}

here, qstn is NSString and name is UILabel. My application crashes at [sender title] line. In the console I found this:

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[UIRoundedRectButton title]: unrecognized selector sent to instance 0x5294d0

Anything wrong with 'CGRectMake' that the button was made of?

thanks in advance, your previous answers were helpful.