Objective-C add an NSButton to my iphone app at ru

问题:

I am absolutely clueless on this front! Step-by-step explanation earns bonus points.

回答1:

In iOS We have UIButtons (not NSButtons)

Here is how to create an UIButton programmatically:

UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect]; //3
[button setFrame:CGRectMake(320, 0, 100,100 )];
[button setTitle:@"PressMe!" forState:UIControlStateNormal]; 
[button addTarget:self action:@selector(buttonPressed:) forControlEvents:UIControlEventTouchUpInside];//2
[aView addSubview:button]; //1

and :

- (void)buttonPressed:(UIButton *)sender{

    //do something here ;)
    [sender setTitle:@"PressMe!. Again" forState:UIControlStateNormal];


}

1: if you are in a UIViewController, then aView will be self.view if you are somewhere else, just pass the view that will contain your button

2: the easiest case is like that but you can set any object as a target. That object must have to have the method you pass in the @selector(...). Otherwise you app will crash when pressing the button.

回答2:

Not exactly sure of all the steps to do that in code, but what I would do is use the interface builder to create the button where you want it. Then when you load the view, make the button hidden in the viewDidLoad or viewDidAppear method. Make the button visible when you need to. Hope this helps.