XIB视图的边界值较大，不适合屏幕

Question

I have a XIB view.

When i added it to my view, i want the width and height to fit the iOS device.

However, it doesn't fit.

If i use autolayout it would fit the screen. But how do i use it ?

In the code example below, it takes the Bounds of the XIB file. Therefore it doesn't fit the view. How can i solve this?

-(id)initWithFrame:(CGRect)frame{

    self = [super initWithFrame:frame];

    if (self) {

        self.myView=[[[NSBundle mainBundle] loadNibNamed:@"MyView" owner:self options:nil] lastObject];

        self.bounds=self.myView.bounds;

        [self addSubview:self.myView];

    }

    return self;

}

Answer 1

Load your view, then

    [_subview setTranslatesAutoresizingMaskIntoConstraints:NO];
    [_contentView addSubview:_subview];
    [self activateConstraintsForView:_subview respectToParentView:_contentView];

Use this function :

- (void)activateConstraintsForView:(UIView *)view respectToParentView:(UIView *)parentView
{

    NSLayoutConstraint *bottomConstraint = [NSLayoutConstraint constraintWithItem:view
                                                                    attribute:NSLayoutAttributeBottom
                                                                    relatedBy:NSLayoutRelationEqual
                                                                       toItem:parentView
                                                                    attribute:NSLayoutAttributeBottom
                                                                   multiplier:1.0
                                                                     constant:0];

    NSLayoutConstraint *topConstraint = [NSLayoutConstraint constraintWithItem:view
                                                                 attribute:NSLayoutAttributeTop
                                                                 relatedBy:NSLayoutRelationEqual
                                                                    toItem:parentView
                                                                 attribute:NSLayoutAttributeTop
                                                                multiplier:1.0
                                                                  constant:0];

    NSLayoutConstraint *leftConstraint = [NSLayoutConstraint constraintWithItem:view
                                                                  attribute:NSLayoutAttributeLeft
                                                                  relatedBy:NSLayoutRelationEqual
                                                                     toItem:parentView
                                                                  attribute:NSLayoutAttributeLeft
                                                                 multiplier:1.0
                                                                   constant:0];

    NSLayoutConstraint *rightConstraint = [NSLayoutConstraint constraintWithItem:view
                                                                   attribute:NSLayoutAttributeRight
                                                                   relatedBy:NSLayoutRelationEqual
                                                                      toItem:parentView
                                                                   attribute:NSLayoutAttributeRight
                                                                  multiplier:1.0
                                                                    constant:0];

    [NSLayoutConstraint activateConstraints:[NSArray arrayWithObjects:topConstraint, leftConstraint, bottomConstraint, rightConstraint, nil]] ;
 }

Hope, it helps.

Answer 2

In your initWithFrame method add this at the end:

[self setConstraintsOfView:self.myView withRespectToParentView:self];

And add the method below at the end of your class:

-(void)setConstraintsOfView:(UIView *)subView withRespectToParentView:(UIView *)parentView
{
    NSDictionary *viewsDictionary = @{@"subView":subView};

    NSDictionary *metrics =@{@"offset":@0};

    NSArray *heightConstraint = [NSLayoutConstraint constraintsWithVisualFormat:@"V:|-offset-[subView]-offset-|"
                                                                        options:0
                                                                        metrics:metrics
                                                                          views:viewsDictionary];

    NSArray *widthConstraint = [NSLayoutConstraint constraintsWithVisualFormat:@"H:|-offset-[subView]-offset-|"
                                                                       options:0
                                                                       metrics:metrics
                                                                         views:viewsDictionary];

    [parentView addConstraints:heightConstraint];

    [parentView addConstraints:widthConstraint];
}

VFL is much easier than setting each constraints. This method sets the top, bottom, leading and trailing space = 0 of subview with respect to superview.

I think you want to achieve this though: https://github.com/PrajeetShrestha/ConstraintTest