UIButton doesn't set center

Question

I have a button I added manually on the storyboard. I would like when the screen loads, to this button sets its center with the coordination I give to it by

-(void)viewWillLayoutSubviews{
    NSLog(@"Will Layout");
    CGPoint buttonPoint;
    buttonPoint.y = self.view.frame.size.height - 50;
    buttonPoint.x = self.view.frame.size.width /2;

    [menuButton setCenter:buttonPoint];
}

But nothing changes, the button stays still on the place I first dragged it. What am I doing wrong?

Answer 1

It's very simple for both the modern AutoLayout based and old legacy Springs&Struts based layout management approach.

AUTOLAYOUT

You simply set up two constraints that will keep the button in the horizontal middle and in the vertical middle minus 50 points up.

SPRINGS & STRUTS

You will make sure the button is set to be in the center by setting the autoresizing mask properly in the Size inspector. Then in code, in view controller's viewDidLoad method, you will fix the 50 points offset.

(Some might suggest viewWillLayoutSubviews, but let's not complicate it for now.)

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.button.frame = CGRectMake(self.button.frame.origin.x,
                                   self.button.frame.origin.y - 50,
                                   self.button.frame.size.width,
                                   self.button.frame.size.height);

/// other code....
}