Objective C syntax for message passing - iphone

Question

I'm trying following task:
I know we can calla method on button click by using:
[button addTarget:self action:#selector(performModalActionForButton)
forControlEvents:UIControlEventTouchUpInside];
Method is like :
(void) performModalActionForButton:(NSString *)str
{
}
I want to send a string on button click to one method. How can I achieve this?
Thanks

Answer 1

there are two small mistakes in your code..
if you use #selector and want to choose a function with a parameter you have do add a : ... so it is #selector(performModalActionForButton:)
the object passed to the function always the sender of the message .. so the function would be:
- (void) performModalActionForButton:(UIButton *)button
{
}
In the function you can check the text on the button then... or the tag or whatever you want.

Answer 2

You have the button click trigger an action method that then sends the message whose argument is the string you want to send:
[button addTarget:self action:#selector(performModalActionForButton:)
forControlEvents:UIControlEventTouchUpInside];
- (IBAction)performModalActionForButton:(id)sender
{
NSString *string = /* get the string you want to send */;
[obj doSomethingWithString:string];
}