Question

I want to pass a variable to a UIButton action, for example

NSString *string=@'one'; [downbutton addTarget:self action:@selector(action1:string)      forControlEvents:UIControlEventTouchUpInside]; 

and my action function is like:

-(void) action1:(NSString *)string{ } 

However, it returns a syntax error. How to pass a variable to a UIButton action?

Answer 1

Change it to read:

[downbutton addTarget:self action:@selector(action1:) forControlEvents:UIControlEventTouchUpInside]; 

I don’t know about the Iphone SDK, but the target of a button action probably receives an id (usually named sender).

- (void) buttonPress:(id)sender; 

Within the method call, sender should be the button in your case, allowing you to read properties such as it’s name, tag, etc.