中心视图在另一个视图内

Question

I have a view called profile which is taking (0,0,320,60) size in storyboard which is taking full width but 60 height, and i am trying to place another view called ranking inside it at the center and what ever the device is iPhone4s,5s,6s,6 it should just take my view and put it at the center.

Here is what i tried:

ranking.frame = CGRectMake(0, 0, 120, 60);
ranking.center = self.Profile.center;

The current code is not centering my view In all devices. what can i do to do it dynamically ?

Answer 1

You can use AutoLayout with the following method:

+ (void)centerView:(UIView *)view inContainerView:(UIView *)containerView withSuperView:(UIView *)superView
{
    [superView addConstraint:[NSLayoutConstraint constraintWithItem:view attribute:NSLayoutAttributeCenterY relatedBy:NSLayoutRelationEqual toItem:containerView attribute:NSLayoutAttributeCenterY multiplier:1.0 constant:0.0]];
    [superView addConstraint:[NSLayoutConstraint constraintWithItem:view attribute:NSLayoutAttributeCenterX relatedBy:NSLayoutRelationEqual toItem:containerView attribute:NSLayoutAttributeCenterX multiplier:1.0 constant:0.0]];
}

You can add the method above in your ViewController or in a helper class. Remember to set the translatesAutoresizingMaskIntoConstraints property to false before using AutoLayout on your view.

So if ranking is your subview and self.Profile is your superView you can do the following.

UIView *ranking = [[UIView alloc] init];
ranking.translatesAutoresizingMaskIntoConstraints = false;
[self.Profile addSubview:ranking];
[[self class] centerView:ranking inContainerView:self.Profile withSuperView:self.Profile];
[self.Profile addConstraint:[NSLayoutConstraint constraintWithItem:ranking attribute:NSLayoutAttributeWidth relatedBy:NSLayoutRelationEqual toItem:nil attribute:NSLayoutAttributeNotAnAttribute multiplier:1.0 constant:120]];
[self.Profile addConstraint:[NSLayoutConstraint constraintWithItem:ranking attribute:NSLayoutAttributeHeight relatedBy:NSLayoutRelationEqual toItem:nil attribute:NSLayoutAttributeNotAnAttribute multiplier:1.0 constant:60]];