blocks|key|89298|text|包含UITextView的视图将由AutoLayout使用setBounds指定其大小。所以，这就是我所做的。superview最初设置了所有其他约束，最后我为UITextView的高度设置了一个特殊的约束，并将其保存在一个实例变量中。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|89299|_descriptionHeightConstraint+=+[NSLayoutConstraint+constraintWithItem:_descriptionTextView
+++++++++++++++++++++++++++++++++attribute:NSLayoutAttributeHeight+
+++++++++++++++++++++++++++++++++relatedBy:NSLayoutRelationEqual+
++++++++++++++++++++++++++++++++++++toItem:nil+
+++++++++++++++++++++++++++++++++attribute:NSLayoutAttributeNotAnAttribute+
++++++++++++++++++++++++++++++++multiplier:0.f+
+++++++++++++++++++++++++++++++++constant:100];

[self+addConstraint:_descriptionHeightConstraint];|code-block|syntax|javascript|89300|在setBounds方法中，我随后更改了常量的值。|89301|-(void)+setBounds:(CGRect)bounds
{
++++[super+setBounds:bounds];

++++_descriptionTextView.frame+=+bounds;
++++CGSize+descriptionSize+=+_descriptionTextView.contentSize;

++++[_descriptionHeightConstraint+setConstant:descriptionSize.height];

++++[self+layoutIfNeeded];
}|89302|entityMap^0|T|9|0|0|1|9|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|T|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|U|8|@$9|V|A|W|B|C]]|D|@]|E|$]]|$1|M|3|N|5|H|7|X|8|@]|D|@]|E|$I|J]]|$1|O|3|-4|5|6|7|Y|8|@]|D|@]|E|$]]]|P|$]]

The view containing UITextView will be assigned its size with <code>setBounds</code> by AutoLayout. So, this is what I did. The superview is initially set up all the other constraints as they should be, and in the end I put one special constraint for UITextView's height, and I saved it in an instance variable.

<pre><code>_descriptionHeightConstraint = [NSLayoutConstraint constraintWithItem:_descriptionTextView
 attribute:NSLayoutAttributeHeight 
 relatedBy:NSLayoutRelationEqual 
 toItem:nil 
 attribute:NSLayoutAttributeNotAnAttribute 
 multiplier:0.f 
 constant:100];

[self addConstraint:_descriptionHeightConstraint];
</code></pre>

In the <code>setBounds</code> method, I then changed the value of the constant.

<pre><code>-(void) setBounds:(CGRect)bounds
{
 [super setBounds:bounds];

 _descriptionTextView.frame = bounds;
 CGSize descriptionSize = _descriptionTextView.contentSize;

 [_descriptionHeightConstraint setConstant:descriptionSize.height];

 [self layoutIfNeeded];
}
</code></pre>

blocks|key|89325|text|你也可以在没有UITextView子类化的情况下做到这一点。看一看my+answer+to+How+do+I+size+a+UITextView+to+its+content+on+iOS+7?|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|89326|使用此表达式的值：|89327|[textView+sizeThatFits:CGSizeMake(textView.frame.size.width,+CGFLOAT_MAX)].height|code-block|syntax|javascript|89328|来更新textView's+height+UILayoutConstraint的constant。|89329|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/a/19436419/242933^0|7|A|X|1S|0|0|0|0|3|8|L|I|14|8|0^^$0|@$1|2|3|4|5|6|7|W|8|@$9|X|A|Y|B|C]]|D|@$9|Z|A|10|1|11]]|E|$]]|$1|F|3|G|5|6|7|12|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|13|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|14|8|@$9|15|A|16|B|C]|$9|17|A|18|B|C]|$9|19|A|1A|B|C]]|D|@]|E|$]]|$1|O|3|-4|5|6|7|1B|8|@]|D|@]|E|$]]]|P|$Q|$5|R|S|T|E|$U|V]]]]

You can also do it without subclassing <code>UITextView</code>. Have a look at <a href="https://stackoverflow.com/a/19436419/242933">my answer to How do I size a UITextView to its content on iOS 7?</a>

Use the value of this expression:

<pre><code>[textView sizeThatFits:CGSizeMake(textView.frame.size.width, CGFLOAT_MAX)].height
</code></pre>

to update the <code>constant</code> of the <code>textView</code>'s height <code>UILayoutConstraint</code>.

blocks|key|89380|text|摘要:禁用文本视图的滚动，并且不限制其高度。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|89381|要以编程方式完成此操作，请将以下代码放入viewDidLoad中|offset|length|style|CODE|89382|let+textView+=+UITextView(frame:+.zero,+textContainer:+nil)
textView.backgroundColor+=+.yellow+//+visual+debugging
textView.isScrollEnabled+=+false+++//+causes+expanding+height
view.addSubview(textView)

//+Auto+Layout
textView.translatesAutoresizingMaskIntoConstraints+=+false
let+safeArea+=+view.safeAreaLayoutGuide
NSLayoutConstraint.activate([
++++textView.topAnchor.constraint(equalTo:+safeArea.topAnchor),
++++textView.leadingAnchor.constraint(equalTo:+safeArea.leadingAnchor),
++++textView.trailingAnchor.constraint(equalTo:+safeArea.trailingAnchor)
])|code-block|syntax|javascript|89383|要在Interface+Builder中执行此操作，请选择文本视图，取消选中Attributes+Inspector中启用的滚动，然后手动添加约束。|89384|注意:如果在文本视图的上方/下方有其他视图，请考虑使用UIStackView将其全部排列。|89385|entityMap^0|0|K|B|0|0|0|R|B|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|T|8|@$D|U|E|V|F|G]]|9|@]|A|$]]|$1|H|3|I|5|J|7|W|8|@]|9|@]|A|$K|L]]|$1|M|3|N|5|6|7|X|8|@]|9|@]|A|$]]|$1|O|3|P|5|6|7|Y|8|@$D|Z|E|10|F|G]]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|11|8|@]|9|@]|A|$]]]|R|$]]

Summary: Disable scrolling of your text view, and don't constraint its height.

To do this programmatically, put the following code in <code>viewDidLoad</code>:

<pre><code>let textView = UITextView(frame: .zero, textContainer: nil)
textView.backgroundColor = .yellow // visual debugging
textView.isScrollEnabled = false // causes expanding height
view.addSubview(textView)

// Auto Layout
textView.translatesAutoresizingMaskIntoConstraints = false
let safeArea = view.safeAreaLayoutGuide
NSLayoutConstraint.activate([
 textView.topAnchor.constraint(equalTo: safeArea.topAnchor),
 textView.leadingAnchor.constraint(equalTo: safeArea.leadingAnchor),
 textView.trailingAnchor.constraint(equalTo: safeArea.trailingAnchor)
])
</code></pre>

To do this in Interface Builder, select the text view, uncheck Scrolling Enabled in the Attributes Inspector, and add the constraints manually.

Note: If you have other view/s above/below your text view, consider using a <code>UIStackView</code> to arrange them all.

blocks|key|306384|text|顺便说一句，我使用子类和覆盖内部内容大小构建了一个扩展的UITextView。我在UITextView中发现了一个bug，您可能希望在自己的实现中进行调查。以下是问题所在：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|306385|如果您一次键入单个字母，则扩展的文本视图将变小以适应不断增长的文本。但是如果你粘贴一大堆文本到其中，它不会变小，但文本会向上滚动，顶部的文本看不到。|306386|解决方案:在您的子类中覆盖setBounds：。由于某种未知的原因，粘贴导致bunds.Origin.y值为非zee(在我看到的每个例子中都是33)。因此，我重写了setBounds:始终将bunds.Origin.y设置为零。已修复此问题。|306387|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|H|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|I|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|J|8|@]|9|@]|A|$]]|$1|F|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|G|$]]

BTW, I built an expanding UITextView using a subclass and overriding intrinsic content size. I discovered a bug in UITextView that you might want to investigate in your own implementation. Here is the problem:

The expanding text view would grow down to accommodate the growing text if you type single letters at a time. But if you paste a bunch of text into it, it would not grow down but the text would scroll up and the text at the top was out of view.

The solution:
Override setBounds: in your subclass. For some unknown reason, the pasting caused the bounds.origin.y value to be non-zee (33 in every case that I saw). So I overrode setBounds: to always set the bounds.origin.y to zero. Fixed the problem.

blocks|key|306392|text|Obj+C:

#import+<UIKit/UIKit.h>

@interface+ViewController+:+UIViewController

@property+(nonatomic)+UITextView+*textView;
@end



#import+"ViewController.h"

@interface+ViewController+()

@end

@implementation+ViewController

@synthesize+textView;

-+(void)viewDidLoad{
++++[super+viewDidLoad];
++++[self.view+setBackgroundColor:[UIColor+grayColor]];
++++self.textView+=+[[UITextView+alloc]+initWithFrame:CGRectMake(30,10,250,20)];
++++self.textView.delegate+=+self;
++++[self.view+addSubview:self.textView];
}

-+(void)didReceiveMemoryWarning{
++++[super+didReceiveMemoryWarning];
}

-+(void)textViewDidChange:(UITextView+*)txtView{
++++float+height+=+txtView.contentSize.height;
++++[UITextView+beginAnimations:nil+context:nil];
++++[UITextView+setAnimationDuration:0.5];

++++CGRect+frame+=+txtView.frame;
++++frame.size.height+=+height+%2B+10.0;+//Give+it+some+padding
++++txtView.frame+=+frame;
++++[UITextView+commitAnimations];
}

@end|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|306393|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>Obj C:

#import &lt;UIKit/UIKit.h&gt;

@interface ViewController : UIViewController

@property (nonatomic) UITextView *textView;
@end



#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

@synthesize textView;

- (void)viewDidLoad{
 [super viewDidLoad];
 [self.view setBackgroundColor:[UIColor grayColor]];
 self.textView = [[UITextView alloc] initWithFrame:CGRectMake(30,10,250,20)];
 self.textView.delegate = self;
 [self.view addSubview:self.textView];
}

- (void)didReceiveMemoryWarning{
 [super didReceiveMemoryWarning];
}

- (void)textViewDidChange:(UITextView *)txtView{
 float height = txtView.contentSize.height;
 [UITextView beginAnimations:nil context:nil];
 [UITextView setAnimationDuration:0.5];

 CGRect frame = txtView.frame;
 frame.size.height = height + 10.0; //Give it some padding
 txtView.frame = frame;
 [UITextView commitAnimations];
}

@end
</code></pre>

blocks|key|306418|text|我发现在你可能仍然需要将isScrollEnabled设置为true以允许合理的UI交互的情况下，这并不是完全不常见的。一个简单的例子是，如果您想要允许自动扩展文本视图，但仍然将它的最大高度限制为UITableView中的合理高度。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|306419|这是我提出的UITextView的一个子类，它允许使用自动布局自动扩展，但您仍然可以将其限制为最大高度，并且它将根据高度管理视图是否可滚动。默认情况下，如果以这种方式设置约束，视图将无限扩展。|306420|import+UIKit

class+FlexibleTextView:+UITextView+{
++++//+limit+the+height+of+expansion+per+intrinsicContentSize
++++var+maxHeight:+CGFloat+=+0.0
++++private+let+placeholderTextView:+UITextView+=+{
++++++++let+tv+=+UITextView()

++++++++tv.translatesAutoresizingMaskIntoConstraints+=+false
++++++++tv.backgroundColor+=+.clear
++++++++tv.isScrollEnabled+=+false
++++++++tv.textColor+=+.disabledTextColor
++++++++tv.isUserInteractionEnabled+=+false
++++++++return+tv
++++}()
++++var+placeholder:+String?+{
++++++++get+{
++++++++++++return+placeholderTextView.text
++++++++}
++++++++set+{
++++++++++++placeholderTextView.text+=+newValue
++++++++}
++++}

++++override+init(frame:+CGRect,+textContainer:+NSTextContainer?)+{
++++++++super.init(frame:+frame,+textContainer:+textContainer)
++++++++isScrollEnabled+=+false
++++++++autoresizingMask+=+[.flexibleWidth,+.flexibleHeight]
++++++++NotificationCenter.default.addObserver(self,+selector:+#selector(UITextInputDelegate.textDidChange(_:)),+name:+Notification.Name.UITextViewTextDidChange,+object:+self)
++++++++placeholderTextView.font+=+font
++++++++addSubview(placeholderTextView)

++++++++NSLayoutConstraint.activate([
++++++++++++placeholderTextView.leadingAnchor.constraint(equalTo:+leadingAnchor),
++++++++++++placeholderTextView.trailingAnchor.constraint(equalTo:+trailingAnchor),
++++++++++++placeholderTextView.topAnchor.constraint(equalTo:+topAnchor),
++++++++++++placeholderTextView.bottomAnchor.constraint(equalTo:+bottomAnchor),
++++++++])
++++}

++++required+init?(coder+aDecoder:+NSCoder)+{
++++++++fatalError("init(coder:)+has+not+been+implemented")
++++}

++++override+var+text:+String!+{
++++++++didSet+{
++++++++++++invalidateIntrinsicContentSize()
++++++++++++placeholderTextView.isHidden+=+!text.isEmpty
++++++++}
++++}

++++override+var+font:+UIFont?+{
++++++++didSet+{
++++++++++++placeholderTextView.font+=+font
++++++++++++invalidateIntrinsicContentSize()
++++++++}
++++}

++++override+var+contentInset:+UIEdgeInsets+{
++++++++didSet+{
++++++++++++placeholderTextView.contentInset+=+contentInset
++++++++}
++++}

++++override+var+intrinsicContentSize:+CGSize+{
++++++++var+size+=+super.intrinsicContentSize

++++++++if+size.height+==+UIViewNoIntrinsicMetric+{
++++++++++++//+force+layout
++++++++++++layoutManager.glyphRange(for:+textContainer)
++++++++++++size.height+=+layoutManager.usedRect(for:+textContainer).height+%2B+textContainerInset.top+%2B+textContainerInset.bottom
++++++++}

++++++++if+maxHeight+>+0.0+&&+size.height+>+maxHeight+{
++++++++++++size.height+=+maxHeight

++++++++++++if+!isScrollEnabled+{
++++++++++++++++isScrollEnabled+=+true
++++++++++++}
++++++++}+else+if+isScrollEnabled+{
++++++++++++isScrollEnabled+=+false
++++++++}

++++++++return+size
++++}

++++@objc+private+func+textDidChange(_+note:+Notification)+{
++++++++//+needed+incase+isScrollEnabled+is+set+to+true+which+stops+automatically+calling+invalidateIntrinsicContentSize()
++++++++invalidateIntrinsicContentSize()
++++++++placeholderTextView.isHidden+=+!text.isEmpty
++++}
}|code-block|syntax|javascript|306421|作为额外的好处，它支持包含类似于UILabel的占位符文本。|306422|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|N|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|O|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|P|8|@]|9|@]|A|$]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

I've found it's not entirely uncommon in situations where you may still need isScrollEnabled set to true to allow a reasonable UI interaction. A simple case for this is when you want to allow an auto expanding text view but still limit it's maximum height to something reasonable in a UITableView.

Here's a subclass of UITextView I've come up with that allows auto expansion with auto layout but that you could still constrain to a maximum height and which will manage whether the view is scrollable depending on the height. By default the view will expand indefinitely if you have your constraints setup that way.

<pre><code>import UIKit

class FlexibleTextView: UITextView {
 // limit the height of expansion per intrinsicContentSize
 var maxHeight: CGFloat = 0.0
 private let placeholderTextView: UITextView = {
 let tv = UITextView()

 tv.translatesAutoresizingMaskIntoConstraints = false
 tv.backgroundColor = .clear
 tv.isScrollEnabled = false
 tv.textColor = .disabledTextColor
 tv.isUserInteractionEnabled = false
 return tv
 }()
 var placeholder: String? {
 get {
 return placeholderTextView.text
 }
 set {
 placeholderTextView.text = newValue
 }
 }

 override init(frame: CGRect, textContainer: NSTextContainer?) {
 super.init(frame: frame, textContainer: textContainer)
 isScrollEnabled = false
 autoresizingMask = [.flexibleWidth, .flexibleHeight]
 NotificationCenter.default.addObserver(self, selector: #selector(UITextInputDelegate.textDidChange(_:)), name: Notification.Name.UITextViewTextDidChange, object: self)
 placeholderTextView.font = font
 addSubview(placeholderTextView)

 NSLayoutConstraint.activate([
 placeholderTextView.leadingAnchor.constraint(equalTo: leadingAnchor),
 placeholderTextView.trailingAnchor.constraint(equalTo: trailingAnchor),
 placeholderTextView.topAnchor.constraint(equalTo: topAnchor),
 placeholderTextView.bottomAnchor.constraint(equalTo: bottomAnchor),
 ])
 }

 required init?(coder aDecoder: NSCoder) {
 fatalError("init(coder:) has not been implemented")
 }

 override var text: String! {
 didSet {
 invalidateIntrinsicContentSize()
 placeholderTextView.isHidden = !text.isEmpty
 }
 }

 override var font: UIFont? {
 didSet {
 placeholderTextView.font = font
 invalidateIntrinsicContentSize()
 }
 }

 override var contentInset: UIEdgeInsets {
 didSet {
 placeholderTextView.contentInset = contentInset
 }
 }

 override var intrinsicContentSize: CGSize {
 var size = super.intrinsicContentSize

 if size.height == UIViewNoIntrinsicMetric {
 // force layout
 layoutManager.glyphRange(for: textContainer)
 size.height = layoutManager.usedRect(for: textContainer).height + textContainerInset.top + textContainerInset.bottom
 }

 if maxHeight &gt; 0.0 &amp;&amp; size.height &gt; maxHeight {
 size.height = maxHeight

 if !isScrollEnabled {
 isScrollEnabled = true
 }
 } else if isScrollEnabled {
 isScrollEnabled = false
 }

 return size
 }

 @objc private func textDidChange(_ note: Notification) {
 // needed incase isScrollEnabled is set to true which stops automatically calling invalidateIntrinsicContentSize()
 invalidateIntrinsicContentSize()
 placeholderTextView.isHidden = !text.isEmpty
 }
}
</code></pre>

As a bonus there's support for including placeholder text similar to UILabel.

blocks|key|306466|text|你可以通过故事板来实现，只需禁用“启用滚动功能”：)|type|unstyled|depth|inlineStyleRanges|entityRanges|data|306467|​|306468|📷|atomic|offset|length|306469|306470|entityMap|0|IMAGE|mutability|IMMUTABLE|imageUrl|https://ask.qcloudimg.com/http-save/yehe-900000/b98056cefc04d613271c7b2084c95f2f.png|imageAlt^0|0|0|0|1|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|T|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|U|8|@]|9|@$G|V|H|W|1|X]]|A|$]]|$1|I|3|C|5|6|7|Y|8|@]|9|@]|A|$]]|$1|J|3|-4|5|6|7|Z|8|@]|9|@]|A|$]]]|K|$L|$5|M|N|O|A|$P|Q|R|-4]]]]

You can do it through storyboard, just disable "Scrolling Enabled":)

<a href="https://i.stack.imgur.com/6oh5b.png" rel="noreferrer"><img src="https://i.stack.imgur.com/6oh5b.png" alt="StoryBoard"></a>

blocks|key|306490|text|需要注意的一件重要事情：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|306491|由于UITextView是UIScrollView的子类，因此它受制于UIViewController的automaticallyAdjustsScrollViewInsets属性。|306492|如果您正在设置布局，并且TextView是UIViewControllers层次结构中的第一个子视图，则如果automaticallyAdjustsScrollViewInsets为真，它的contentInsets将被修改，有时会导致自动布局中出现意外行为。|306493|因此，如果您在自动布局和文本视图方面遇到问题，请尝试在视图控制器上设置automaticallyAdjustsScrollViewInsets+=+false，或者在层次结构中向前移动textView。|offset|length|style|CODE|306494|entityMap^0|0|0|0|Z|18|0^^$0|@$1|2|3|4|5|6|7|N|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|O|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|P|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|Q|8|@$H|R|I|S|J|K]]|9|@]|A|$]]|$1|L|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|M|$]]

An important thing to note: 

Since UITextView is a subclass of UIScrollView, it is subject to the automaticallyAdjustsScrollViewInsets property of UIViewController. 

If you are setting up the layout and the TextView is the the first subview in a UIViewControllers hierarchy, it will have its contentInsets modified if automaticallyAdjustsScrollViewInsets is true sometimes causing unexpected behaviour in auto layout.

So if you're having problems with auto layout and text views, try setting <code>automaticallyAdjustsScrollViewInsets = false</code> on the view controller or moving the textView forward in the hierarchy.

blocks|key|89520|text|维他命水的答案对我很有效。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|89521|如果文本视图的文本在编辑期间上下跳动，请在设置[textView+setScrollEnabled:NO];后设置Size+Inspector+>+Scroll+View+>+Content+Insets+>+Never。|offset|length|style|CODE|89522|希望能有所帮助。|89523|entityMap^0|0|N|V|1L|1H|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|M|8|@$D|N|E|O|F|G]|$D|P|E|Q|F|G]]|9|@]|A|$]]|$1|H|3|I|5|6|7|R|8|@]|9|@]|A|$]]|$1|J|3|-4|5|6|7|S|8|@]|9|@]|A|$]]]|K|$]]

vitaminwater's answer is working for me. 

If your textview's text is bouncing up and down during edit, after setting <code>[textView setScrollEnabled:NO];</code>, set <code>Size Inspector &gt; Scroll View &gt; Content Insets &gt; Never</code>.

Hope it helps.

blocks|key|306527|text|把隐藏的UILabel放在你的文本视图下面。标签行=+0。设置UITextView的约束等于UILabel+(centerX，centerY，width，height)。即使你离开了textView的滚动行为，它也能工作。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|306528|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

Place hidden UILabel underneath your textview. Label lines = 0. Set constraints of UITextView to be equal to the UILabel (centerX, centerY, width, height). Works even if you leave scroll behaviour of textView.

blocks|key|306539|text|这里有一个快速的解决方案：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|306540|如果已将textview的clipsToBounds属性设置为false，则可能会发生此问题。如果你简单地删除它，问题就会消失。|306541|myTextView.clipsToBounds+=+false+//delete+this+line|code-block|syntax|javascript|306542|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|L|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|M|8|@]|9|@]|A|$G|H]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

Here's a quick solution:

This problem may occur if you have set clipsToBounds property to false of your textview. If you simply delete it, the problem goes away.

<pre><code>myTextView.clipsToBounds = false //delete this line
</code></pre>

blocks|key|306568|text|我看到多个答案建议简单地关闭scrollEnabled。这是最好的解决方案。我写这个答案是为了解释为什么它是有效的。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|306569|如果为scrollEnabled+==+NO，则UITextView实现intrinsicContentSize属性。getter方法的反汇编如下所示：|306570|-+(CGSize)intrinsicContentSize+{
++if+(self.scrollEnabled)+{
++++return+CGSizeMake(UIViewNoIntrinsicMetric,+UIViewNoIntrinsicMetric);
++}+else+{
++++//+Calculate+and+return+intrinsic+content+size+based+on+current+width.
++}
}|code-block|syntax|javascript|306571|这意味着你只需要确保文本视图的宽度受到足够的限制，然后你就可以使用固有的内容高度(通过自动布局内容拥抱/压缩抵抗优先级或在手动布局期间直接使用该值)。|306572|不幸的是，此行为并未记录在案。苹果本可以轻松地为我们所有人省去一些令人头疼的…不需要额外的高度约束、子类化等。|306573|entityMap^0|E|D|0|3|J|O|A|10|K|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|V|8|@$9|W|A|X|B|C]|$9|Y|A|Z|B|C]|$9|10|A|11|B|C]]|D|@]|E|$]]|$1|H|3|I|5|J|7|12|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|13|8|@]|D|@]|E|$]]|$1|O|3|P|5|6|7|14|8|@]|D|@]|E|$]]|$1|Q|3|-4|5|6|7|15|8|@]|D|@]|E|$]]]|R|$]]

I see multiple answers suggest simply turning off <code>scrollEnabled</code>. This is the best solution. I’m writing this answer to explain why it works.
<code>UITextView</code> implements the <code>intrinsicContentSize</code> property if <code>scrollEnabled == NO</code>. The disassembly of the getter method looks like this:
<pre><code>- (CGSize)intrinsicContentSize {
 if (self.scrollEnabled) {
 return CGSizeMake(UIViewNoIntrinsicMetric, UIViewNoIntrinsicMetric);
 } else {
 // Calculate and return intrinsic content size based on current width.
 }
}
</code></pre>
That means you just need to make sure the width of the text view is constrained enough and then you can use the intrinsic content height (either via Auto Layout content hugging/compression resistance priorities or directly using the value during manual layout).
Unfortunately, this behavior is not documented. Apple could have easily saved us all some headaches… no need for an extra height constraint, subclassing, etc.

I have a view that is laid out completely using auto layout programmatically. I have a UITextView in the middle of the view with items above and below it. Everything works fine, but I want to be able to expand UITextView as text is added. This should push everything below it down as it expands.

I know how to do this the "springs and struts" way, but is there an auto layout way of doing this? The only way I can think of is by removing and re-adding the constraint every time it needs to grow.

UITextView that expands to text using auto layout

我有一个视图，这是完全使用自动布局编程。我在视图的中间有一个UITextView，上面和下面都有项目。一切都很好，但我希望能够在添加文本时扩展UITextView。随着它的扩展，这应该会把它下面的所有东西都压下来。我知道怎么做“弹簧和支柱”的方式，但有没有这样做的自动布局方式？我能想到的唯一方法是在每次需要增长时删除并...

问使用自动布局扩展为文本的UITextView
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