将容器视图嵌入到 UIScrollView

Question

我一直在寻找高低试图找出这个希望有人能提供帮助（我认为这可能相当微不足道，但我只是过度混淆了情况！）

我正在使用 XCode 5 和故事板。我有一个容器视图，它占用了 iPhone 上大约 75% 的屏幕空间。在此之上，我有一些按钮（和其他小部件）。我希望能够在按下其中一个按钮时将视图控制器加载到容器中。

到目前为止，所有这些都可以正常工作，但是正在加载的视图控制器具有不同的大小，并且将来可能会发生变化。我希望能够允许子视图（任意大小）滚动。

我尝试将容器嵌入到滚动视图中，但是作为添加新子视图过程的一部分，您必须设置框架大小，但我希望孩子弄清楚它应该有多大然后相应地设置所有内容。

我不完全确定最好的解决方法是什么（在故事板中设置约束，还是以编程方式？）

任何建议都会很棒！或者教程的链接将非常有用，我能找到的唯一的是将视图控制器添加到容器视图或将视图添加到滚动视图，这些似乎都不像 Xcode 5 (iOS 7) 的预期那样工作

谢谢！

-编辑-

这是我用来展示任意大小的细节视图控制器的代码，其余的都设置在情节提要中（以防万一这对将来的任何人有用！）现在可以了：

- (void)presentDetailController:(UIViewController*)detailVC{

//0. Remove the current Detail View Controller shown
if(self.currentDetailViewController){
    [self removeCurrentDetailViewController];
}

//1. Add the detail controller as child of the container
[self addChildViewController:detailVC];

//2. DO NOT Define the detail controller's view size
//detailVC.view.frame = [self frameForDetailController];

//3. Add the Detail controller's view to the Container's detail view and save a reference to the detail View Controller
[self.detailView addSubview:detailVC.view];
self.currentDetailViewController = detailVC;

// Pin the height to the container to make it scrollable?
[self.detailView addConstraint:[NSLayoutConstraint constraintWithItem:self.detailView attribute:NSLayoutAttributeHeight relatedBy:NSLayoutRelationEqual toItem:nil attribute:NSLayoutAttributeHeight multiplier:1.0f constant:detailVC.view.bounds.size.height]];

//4. Complete the add flow calling the function didMoveToParentViewController
[detailVC didMoveToParentViewController:self];

}

Answer 1

您可以在任一位置设置约束并使其正常工作。秘诀是：您必须将容器视图的约束设置为包含它的滚动视图的顶部、左侧、底部和右侧。然后，自动布局将根据容器视图内部的内容正确计算滚动视图的内容大小。

请参阅 iOS 6 发行说明中标题为 Pure Auto Layout Approach 的部分。甚至还有一些示例代码。

// parentView is the thing you want to add the scroll view to


// setup the scroll view, and add it to the parent view
UIScrollView* scrollView = [[UIScrollView alloc] init];
scrollView.backgroundColor = [UIColor colorWithWhite:0.9f alpha:1.0f];

[parentView addSubview:scrollView];

scrollView.translatesAutoresizingMaskIntoConstraints = NO;

NSDictionary* views = NSDictionaryOfVariableBindings(scrollView);

[parentView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|[scrollView]|" options:0 metrics:nil views:views]];
[parentView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|[scrollView]|" options:0 metrics:nil views:views]];


// set up the content
UILabel* firstLongLabel = [[UILabel alloc] init];
firstLongLabel.numberOfLines = 0;
firstLongLabel.text = @" Four score and seven years ago our fathers brought forth, on this continent, a new nation, conceived in Liberty, and dedicated to the proposition that all men are created equal.\n\nNow we are engaged in a great civil war, testing whether that nation, or any nation so conceived, and so dedicated, can long endure. We are met on a great battle-field of that war. We have come to dedicate a portion of that field, as a final resting-place for those who here gave their lives, that that nation might live. It is altogether fitting and proper that we should do this.";
firstLongLabel.backgroundColor = [UIColor greenColor];

UIButton* middleButton = [UIButton buttonWithType:UIButtonTypeSystem];
[middleButton setTitle:@"Middle Button" forState:UIControlStateNormal];
middleButton.backgroundColor = [UIColor purpleColor];

UILabel* lastLongLabel = [[UILabel alloc] init];
lastLongLabel.numberOfLines = 0;
lastLongLabel.text = @"But, in a larger sense, we can not dedicate, we can not consecrate – we can not hallow – this ground. The brave men, living and dead, who struggled here, have consecrated it far above our poor power to add or detract. The world will little note, nor long remember what we say here, but it can never forget what they did here. It is for us the living, rather, to be dedicated here to the unfinished work which they who fought here have thus far so nobly advanced. It is rather for us to be here dedicated to the great task remaining before us – that from these honored dead we take increased devotion to that cause for which they here gave the last full measure of devotion - that we here highly resolve that these dead shall not have died in vain – that this nation, under God, shall have a new birth of freedom, and that government of the people, by the people, for the people, shall not perish from the earth.";
lastLongLabel.backgroundColor = [UIColor yellowColor];


// now create a content view and add all of our previously created content to it
UIView* contentView = [[UIView alloc] init];
contentView.backgroundColor = [UIColor blueColor];

[contentView addSubview:firstLongLabel];
[contentView addSubview:middleButton];
[contentView addSubview:lastLongLabel];

[scrollView addSubview:contentView];


// and now comes the important part.. the constraints
firstLongLabel.translatesAutoresizingMaskIntoConstraints = middleButton.translatesAutoresizingMaskIntoConstraints = lastLongLabel.translatesAutoresizingMaskIntoConstraints = contentView.translatesAutoresizingMaskIntoConstraints = NO;

views = NSDictionaryOfVariableBindings(firstLongLabel, middleButton, lastLongLabel, contentView);

// first, add constraints dealing with the content inside the content view
// these are simple and should be easily understood
[contentView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|-10-[firstLongLabel]-10-|" options:0 metrics:nil views:views]];
[contentView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|-10-[middleButton]-10-|" options:0 metrics:nil views:views]];
[contentView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|-10-[lastLongLabel]-10-|" options:0 metrics:nil views:views]];

[contentView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|-10-[firstLongLabel]-10-[middleButton]-10-[lastLongLabel]-10-|" options:0 metrics:nil views:views]];

// then add constraints dealing with the content view that we put into the scroll view...
// the trick here is that we lock the content to only partially the width
// of the scroll view's parent. if we don't do that, then the labels will force the scroll
// view to expand horizontally instead of vertically.
//
// as an exercise, you can try locking the left and right to the scroll view instead of the parent view to see what happens
[parentView addConstraint:[NSLayoutConstraint constraintWithItem:contentView attribute:NSLayoutAttributeLeft relatedBy:NSLayoutRelationEqual toItem:parentView attribute:NSLayoutAttributeLeft multiplier:1 constant:10]];
[parentView addConstraint:[NSLayoutConstraint constraintWithItem:contentView attribute:NSLayoutAttributeRight relatedBy:NSLayoutRelationEqual toItem:parentView attribute:NSLayoutAttributeRight multiplier:1 constant:-10]];

// by locking the content view's vertical edges to that of the scroll view, it'll cause the
// scroll view to expand vertically to accomodate the entire content view
[scrollView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|-10-[contentView]-10-|" options:0 metrics:nil views:views]];