How to apply autolayout for UIView in nib?

Question

I am confused with the autolayout on xib/nib. I am comfortable with storyboard autolayout.

What I am trying to do is:

1. I have a storyboard with one view controller with one UIView called borderView. It is constrained correctly.It is resized correctly for iphone 5 and 6. Here is the screenshot of the storyboard:

This is the borderView in iphone 5: (I am trying to add the nib view as a subview to this border view)

2. I created a nib with UIView in it with the dimensions 300 x 300. I want this view to be added to the borderVIew in my ViewController. HEre is the screenshot for my nib.

Note: I didnt gave any height or width constraints anywhere. I just gave leading ,traliing,top and bottom.

and I am trying to add the nib to my borderview as follows:

This is the method in my viewController:

   -(void)viewDidAppear:(BOOL)animated{

    [super viewDidAppear:animated];

    [[NSBundle mainBundle] loadNibNamed:@"AlertView" owner:self options:nil];

    [self.borderView addSubview:self.myAlertViewFromNib];

}

and the result in the iphone 5 is:

As you can see, the nib view is not aligned in the center of the screen (as the border view is aligned center to the screen).

I have no idea of how to give constraints to nib itself. Can anyone please tell me if it is possible to do it in xcode or do I need to give the constraints programmatically?

Mohshin Shah Mohshin Shah · Accepted Answer · 2016-01-13T15:49:48

You want to add the AlertView as a center aligned in the view controller Rather than setting size from the xib just create the perfect constrained XIB view and define macros for sizes as below.

Step 1 have some macros for size

#define kAlertViewWidth 300
#define kAlertViewHeight 300

Step 2 in @interface .Please create on property like this in the viewcontroller

@property (nonatomic, retain) IBOutlet UIView *myViewFromNib;

Getter Method For the property

-(UIView *)myViewFromNib
{
if (!_myViewFromNib) {
    _myViewFromNib = [[[NSBundle mainBundle] loadNibNamed:@"AlertView" owner:self options:nil] objectAtIndex:0];
    _myViewFromNib.translatesAutoresizingMaskIntoConstraints = NO;


}
return _myViewFromNib;
}

//Step 3 in viewDidLoad method

 -(void)viewDidLoad{
  [self setUpConstraints];
}

Method which will add the required constraints

    -(void)setUpConstraints
    {
        \[self.view addSubview:self.myViewFromNib\];
        \[NSLayoutConstraint activateConstraints:@\[\[NSLayoutConstraint constraintWithItem:self.myViewFromNib attribute:NSLayoutAttributeCenterX relatedBy:NSLayoutRelationEqual toItem:self.view attribute:NSLayoutAttributeCenterX multiplier:1.0 constant:0\],

                                                  \[NSLayoutConstraint constraintWithItem:self.myViewFromNib attribute:NSLayoutAttributeCenterY relatedBy:NSLayoutRelationEqual toItem:self.view attribute:NSLayoutAttributeCenterY multiplier:1.0 constant:0\],

                                                  \[NSLayoutConstraint constraintWithItem:self.myViewFromNib attribute:NSLayoutAttributeWidth relatedBy:NSLayoutRelationEqual toItem:nil attribute:NSLayoutAttributeNotAnAttribute multiplier:1.0
                                                                                constant:kAlertViewWidth\],

                                                  \[NSLayoutConstraint constraintWithItem:self.myViewFromNib attribute:NSLayoutAttributeHeight relatedBy:NSLayoutRelationEqual toItem:nil attribute:NSLayoutAttributeNotAnAttribute multiplier:1.0
                                                                                constant:kAlertViewHeight\]\]\];
    }

How to apply autolayout for UIView in nib?

3 Answers