UIControl - changing assigned selectors: addTarget & removeTarget

Question

I\'m using 10 buttons in my interface and need, from time to time, to change the button\'s selector.

Am I required to use:

-(void)removeTarget:(id)ta         


        

Answer 1

Yes, you will need to remove the old target/action or both the old and new actions will be performed.

Answer 2

Yes you should always remove the previously add target before assigning the new target to the button. Like this---

UIButton *btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    [btn setFrame:CGRectMake(50, 50, 200, 50)];

    [btn setTag:101];
    [btn addTarget:self action:@selector(method1) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:btn];


    btn = (UIButton *)[self.view viewWithTag:101];
    [btn removeTarget:self action:@selector(method1) forControlEvents:UIControlEventTouchUpInside];
    [btn addTarget:self action:@selector(method2) forControlEvents:UIControlEventTouchUpInside];

now if you do this

btn = (UIButton *)[self.view viewWithTag:101];
        [btn addTarget:self action:@selector(method2) forControlEvents:UIControlEventTouchUpInside];

then both the methods method1 and method2 will be called.

Hope this helps.