UIView with Auto layout, get his size

Question

I have one UIView witch is populated with content programmatically. Layout in this UIView is made using Auto-layout. This view needs to be subview of one UIScrollView, and it needs to scroll vertically. I have code like this: ``` // self.scrollview is defined in IB and it has constraints to edges (margin:0 0 0 0) UIView *contentView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 1024, MAXFLOAT)]; [contentView setTranslatesAutoresizingMaskIntoConstraints:YES]; // Then I call some my parser which add subviews to the contentView and layout them using constraints. [self.scrollview addSubview:contentView]; [contentView setNeedsLayout]; [contentView layoutIfNeeded]; // Now, I need to know height of the contentView to be able to set contentSize to self.scrollview ``` // UPDATE Ok, I have this UILabel, added to self.content which is UIView created with: `[[UIView alloc] initWithFrame:CGRectMake(self.layoutMargin, self.layoutMargin, 1024 - self.layoutMargin*2, 100)]);` This self.content view…

Accepted Answer

`sizeToFit` is the wrong API to use if you're using autolayout.

The correct api to use for autolayout is `UIView` `systemLayoutSizeFittingSize`:, most likely passing `UILayoutFittingCompressedSize`. This will return a CGSize which is the minimum size that can bound the view with its specified constraints.

Check this link

EDIT: In response to the additional code that was posted...

I've never used the Masonry library before but it's neat!

`UILabels` provide an `intrinsicContentSize` that is large enough to display their text. In order to calculate this size for multi-line text the label needs to know a single dimension that will be fixed, and that is the desired-width dimension via the `preferredMaxLayoutWidth` property. If you don't provide a `preferredMaxLayoutWidth` value (defaults to 0), the label calculates an intrinsic content size AS IF it were laying out a single line of text.

In your code you never set the label's `preferredMaxLayoutWidth` so any layout performed by autolayout that relies on the intrinsicContentSize of the label will not be what you're expecting.

I took your code and distilled it into a new example, which you should be able to copy/paste into a clean viewcontroller subclass:

```
#import "Masonry.h"

@interface TSViewController ()
@end

@implementation TSViewController
{
    UIScrollView*   _scrollView;
    UIView*         _containerView;

UILabel*        _titleLabel;
    UILabel*        _contentLabel;
}

- (void) viewDidLoad
{
    [super viewDidLoad];

self.view.backgroundColor = [UIColor darkGrayColor];

// create/configure our scrollview
    _scrollView = [UIScrollView new];
    _scrollView.translatesAutoresizingMaskIntoConstraints = NO;
    _scrollView.backgroundColor = [UIColor scrollViewTexturedBackgroundColor];
    [self.view addSubview: _scrollView];

// create/configure our container
    _containerView = [UIView new];
    _containerView.translatesAutoresizingMaskIntoConstraints = NO;
    _containerView.backgroundColor = [UIColor yellowColor];
    [_scrollView addSubview: _containerView];

// create/configure our content - title and content labels
    _titleLabel = [UILabel new];
    _titleLabel.translatesAutoresizingMaskIntoConstraints = NO;
    _titleLabel.numberOfLines = 1;
    _titleLabel.font = [UIFont fontWithName: @"Courier" size: 80];
    _titleLabel.text = @"Lorem Ipsum";
    _titleLabel.backgroundColor = [UIColor lightGrayColor];
    _titleLabel.textAlignment = NSTextAlignmentCenter;
    [_containerView addSubview: _titleLabel];

_contentLabel = [UILabel new];
    _contentLabel.translatesAutoresizingMaskIntoConstraints = NO;
    _contentLabel.numberOfLines = 0;
    _contentLabel.font = [UIFont fontWithName: @"Courier" size: 40];
    _contentLabel.text = self.loremIpsum;
    [_containerView addSubview: _contentLabel];

// configure constraints for each view:

[_scrollView mas_makeConstraints: ^(MASConstraintMaker *make) {

// glue the scrollview to its superview with a 20 point inset:

make.top.equalTo( self.view.mas_top ).with.offset( 20 );
        make.left.equalTo( self.view.mas_left ).with.offset( 20 );
        make.right.equalTo( self.view.mas_right ).with.offset( -20 );
        make.bottom.equalTo( self.view.mas_bottom ).with.offset( -20 );
    }];

[_containerView mas_makeConstraints: ^(MASConstraintMaker *make) {

// per the iOS 6.0 Release Notes, this is how to use auto-layout for a container view
        // inside a scrollview.  basically, tie the edges of the containerview to the scrollview.
        // http://developer.apple.com/library/ios/#releasenotes/General/RN-iOSSDK-6_0/
        // see section "Here are some notes regarding Auto Layout support for UIScrollView"

make.top.equalTo( _scrollView.mas_top );
        make.left.equalTo( _scrollView.mas_left );
        make.right.equalTo( _scrollView.mas_right );
        make.bottom.equalTo( _scrollView.mas_bottom );

// match the width of the containerview to the scrollview width:
        make.width.equalTo( _scrollView.mas_width );

// match the height of the containerview to the intrinsic height of the contentlabel + 100 points for our fixed height title

// (this is the magical part.)
        make.height.equalTo( _contentLabel.mas_height ).with.offset( 100 );
    }];

[_titleLabel mas_makeConstraints:^(MASConstraintMaker *make) {

// tie the contentlabel edges to the sides of its container:
        make.top.equalTo( _containerView.mas_top ).with.offset(0);
        make.left.equalTo( _containerView.mas_left ).with.offset(0);
        make.right.equalTo( _containerView.mas_right ).with.offset(0);

// fixed height
        make.height.equalTo( @100 );
    }];

[_contentLabel mas_makeConstraints:^(MASConstraintMaker *make) {

// tie top edge to the bottom of our title
        make.top.equalTo( _titleLabel.mas_bottom );

// tie the remaining edges to the sides of the contain…

UIView with Auto layout, get his size

Solution

Problem