Xcode Label not centered

Question

Programmatically created a scroll view then added a label.

scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0,0,self.view.frame.size.width, self.view.frame.size.height)];

[self.view addSubview:scrollView];

then label

UILabel *errLabel = [[UILabel alloc] init];
errLabel.text = @"Top Label";
//errLabel.frame = CGRectMake(self.view.frame.size.width/2,50,120,20);
errLabel.frame = CGRectMake(CGRectGetWidth(scrollView.frame)/2.00,50,120,20);
errLabel.textAlignment = NSTextAlignmentCenter;
errLabel.layer.borderColor = [UIColor grayColor].CGColor;
errLabel.layer.borderWidth = 3.0;
[errLabel setFont:[UIFont fontWithName:@"Helvetica-Bold" size:14]];
[scrollView addSubview:errLabel];

In the simulator for iPhone 8, 11 Pro Max, and biggest iPad the label is right of center. Is this an iOS 11 bug or am I missing something?

PS - plugged in my iPhone and tested on it - still right of center.... — user3741598, Jan 10 '20 at 16:22

DevKyle · Accepted Answer · 2020-01-10T16:56:31.663

1

This is because the way you are creating the frame for your label, you are starting the frame at the mid point of the scroll view.

This will offset the starting X point to center your label:

errLabel.frame = CGRectMake(CGRectGetWidth(scrollView.frame)/2.00 - 60,50,120,20)

edited Jan 10 '20 at 16:56

answered Jan 10 '20 at 16:49

DevKyle

1,091
6
22

Thanks. Added '-60' (half the 120 frame width of the label) and it's centered. – user3741598 Jan 10 '20 at 16:53
You can as well create a constraint to make sure it stays at the center no matter the text length on it. `[[errLabel.centerXAnchor constraintEqualToAnchor:self.scrollView.centerXAnchor] setActive:YES];` as explained in: https://stackoverflow.com/questions/27624133/programmatically-add-centerx-centery-constraints – BrunoLoops Jan 10 '20 at 16:57

Xcode Label not centered

1 Answers1