ios - How to pass a variable to a UIButton action

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.