对我来说最简单的解决方案是在Storyboard的textView上放一个高度约束，然后将textView和高度约束连接到代码:

@IBOutlet var myAwesomeTextView: UITextView!
@IBOutlet var myAwesomeTextViewHeight: NSLayoutConstraint!

然后在设置文本和段落样式后，在viewDidAppear中添加这个:

self.myAwesomeTextViewHeight.constant = self.myAwesomeTextView.contentSize.height

一些注意事项:

与其他解决方案相比，必须将isScrollEnabled设置为true才能使其工作。 在我的例子中，我在代码中设置自定义属性的字体，因此我必须在viewDidAppear中设置高度(在此之前它不会正常工作)。如果你没有在代码中更改任何文本属性，你应该能够在viewDidLoad或设置文本后的任何地方设置高度。

如果你正在使用滚动视图和内容视图，你想增加高度取决于TextView的内容高度，那么这段代码将帮助你。

希望这能有所帮助，它在iOS9.2中工作得很完美

当然还有set textview。scrollEnabled = NO;

-(void)adjustHeightOfTextView
{
    //this pieces of code will helps to adjust the height of the uitextview View W.R.T content
    //This block of code work will calculate the height of the textview text content height and calculate the height for the whole content of the view to be displayed.Height --> 400 is fixed,it will change if you change anything in the storybord.


CGSize textViewSize = [self.textview sizeThatFits:CGSizeMake(self.view.frame.size.width, self.view.frame.size.height)];//calulcate the content width and height

float textviewContentheight =textViewSize.height;
self.scrollview.contentSize = CGSizeMake(self.textview.frame.size.width,textviewContentheight + 400);//height value is passed
self.scrollview.frame =CGRectMake(self.scrollview.frame.origin.x, self.scrollview.frame.origin.y, self.scrollview.frame.size.width, textviewContentheight+400);

CGRect Frame = self.contentview.frame;
Frame.size.height = textviewContentheight + 400;
[self.contentview setFrame:Frame];

self.textview.frame =CGRectMake(self.textview.frame.origin.x, self.textview.frame.origin.y, self.textview.frame.size.width, textviewContentheight);
[ self.textview setContentSize:CGSizeMake( self.textview.frame.size.width,textviewContentheight)];
self.contenview_heightConstraint.constant = 

self.scrollview.bounds.size.height;
    NSLog(@"%f",self.contenview_heightConstraint.constant);
}

这适用于iOS 6.1和iOS 7:

- (void)textViewDidChange:(UITextView *)textView
{
    CGFloat fixedWidth = textView.frame.size.width;
    CGSize newSize = [textView sizeThatFits:CGSizeMake(fixedWidth, MAXFLOAT)];
    CGRect newFrame = textView.frame;
    newFrame.size = CGSizeMake(fmaxf(newSize.width, fixedWidth), newSize.height);
    textView.frame = newFrame;
}

或在Swift(适用于Swift 4.1在iOS 11)

let fixedWidth = textView.frame.size.width
let newSize = textView.sizeThatFits(CGSize(width: fixedWidth, height: CGFloat.greatestFiniteMagnitude))
textView.frame.size = CGSize(width: max(newSize.width, fixedWidth), height: newSize.height)

如果你想要支持iOS 6.1，那么你还应该:

textview.scrollEnabled = NO;

迅速:

textView.sizeToFit()

使用UITextViewDelegate是最简单的方法:

func textViewDidChange(_ textView: UITextView) {
    textView.sizeToFit()
    textviewHeight.constant = textView.contentSize.height
}

我们可以用约束来做。

为UITextView设置高度约束。

2.为高度限制创建IBOutlet。

 @property (weak, nonatomic) IBOutlet NSLayoutConstraint *txtheightconstraints;

3.不要忘记为你的textview设置委托。

4.

-(void)textViewDidChange:(UITextView *)textView
{
    CGFloat fixedWidth = textView.frame.size.width;
    CGSize newSize = [textView sizeThatFits:CGSizeMake(fixedWidth, MAXFLOAT)];
    CGRect newFrame = textView.frame;
    newFrame.size = CGSizeMake(fmaxf(newSize.width, fixedWidth), newSize.height);
    NSLog(@"this is updating height%@",NSStringFromCGSize(newFrame.size));
    [UIView animateWithDuration:0.2 animations:^{
                  _txtheightconstraints.constant=newFrame.size.height;
    }];

}

然后像这样更新你的约束: