CODEWITHSUNDEEP
iosobjective-ccocoa-touch
humbleCoder
humbleCoder

Reputation: 473

Adding 1pt Bar under navigation bar

I created a view like so and I want to position it right under my navigation bar but the constraint I added does nothing and keeps the bar all the way at the top of the view.

_navSeparator = [[UIView alloc]initWithFrame: CGRectMake(0, 0, 
                 self.view.frame.size.width, 1)];
_navSeparator.backgroundColor = 
                          [UIColor darkColorTheme];
[self.view addSubview:_navSeparator];
[self.view addConstraint:[NSLayoutConstraint 
      constraintWithItem:_navSeparator attribute:NSLayoutAttributeTop 
      relatedBy:NSLayoutRelationEqual toItem:topGuide 
      attribute:NSLayoutAttributeBottom multiplier:1.0 constant:0]];

It has some arbitrary nav title.

Upvotes: 0

Views: 52

Answers (1)

Ax1le
Ax1le

Reputation: 6643

If you want to use AutoLayout please set your view's translatesAutoresizingMaskIntoConstraints NO. Then the Constraint will work and frame will be useless.

So we should add full constraint(leading, top, trailing, height) like:

_navSeparator = [[UIView alloc] init];
_navSeparator.translatesAutoresizingMaskIntoConstraints = NO;
_navSeparator.backgroundColor =
[UIColor blackColor];

[self.view addSubview:_navSeparator];
[self.view addConstraint:[NSLayoutConstraint
                          constraintWithItem:_navSeparator attribute:NSLayoutAttributeTop
                          relatedBy:NSLayoutRelationEqual toItem:self.view.safeAreaLayoutGuide
                          attribute:NSLayoutAttributeTop multiplier:1.0 constant:0]];
[self.view addConstraint:[NSLayoutConstraint
                          constraintWithItem:_navSeparator attribute:NSLayoutAttributeLeading
                          relatedBy:NSLayoutRelationEqual toItem:self.view
                          attribute:NSLayoutAttributeLeading multiplier:1.0 constant:0]];
[self.view addConstraint:[NSLayoutConstraint
                          constraintWithItem:_navSeparator attribute:NSLayoutAttributeTrailing
                          relatedBy:NSLayoutRelationEqual toItem:self.view
                          attribute:NSLayoutAttributeTrailing multiplier:1.0 constant:0]];
[_navSeparator addConstraint:[NSLayoutConstraint
                          constraintWithItem:_navSeparator attribute:NSLayoutAttributeHeight
                          relatedBy:NSLayoutRelationEqual toItem:nil
                          attribute:NSLayoutAttributeNotAnAttribute multiplier:0 constant:1.0]];

Moreover on iOS11+ please modify topGuide to self.view.safeAreaLayoutGuide because in the document we know

Use view.safeAreaLayoutGuide.topAnchor instead of topLayoutGuide.bottomAnchor

Another thing is if you do want a view with 1pt height. You can set its height constraint's constant like 1.0 / [UIScreen mainScreen].scale

Upvotes: 1

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