用键值观察(KVO)很简单，只需创建UITextView的子类，然后做:

private func setup() { // Called from init or somewhere

    fitToContentObservations = [
        textView.observe(\.contentSize) { _, _ in
            self.invalidateIntrinsicContentSize()
        },
        // For some reason the content offset sometimes is non zero even though the frame is the same size as the content size.
        textView.observe(\.contentOffset) { _, _ in
            if self.contentOffset != .zero { // Need to check this to stop infinite loop
                self.contentOffset = .zero
            }
        }
    ]
}
public override var intrinsicContentSize: CGSize {
    return contentSize
}

如果你不想子类化，你可以尝试做textView。bounds = textView。contentSize观察者中的contentSize。

用键值观察(KVO)很简单，只需创建UITextView的子类，然后做:

private func setup() { // Called from init or somewhere

    fitToContentObservations = [
        textView.observe(\.contentSize) { _, _ in
            self.invalidateIntrinsicContentSize()
        },
        // For some reason the content offset sometimes is non zero even though the frame is the same size as the content size.
        textView.observe(\.contentOffset) { _, _ in
            if self.contentOffset != .zero { // Need to check this to stop infinite loop
                self.contentOffset = .zero
            }
        }
    ]
}
public override var intrinsicContentSize: CGSize {
    return contentSize
}

如果你不想子类化，你可以尝试做textView。bounds = textView。contentSize观察者中的contentSize。

希望这能有所帮助:

- (void)textViewDidChange:(UITextView *)textView {
  CGSize textSize = textview.contentSize;
  if (textSize != textView.frame.size)
      textView.frame.size = textSize;
}

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:

使用UITextViewDelegate是最简单的方法:

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

如果有其他人来这里，这个解决方案为我工作，1“Ronnie Liew”+4“user63934”(我的文本从web服务到达): 注意1000(在我的情况下，没有什么比这更大了)

UIFont *fontNormal = [UIFont fontWithName:FONTNAME size:FONTSIZE];

NSString *dealDescription = [client objectForKey:@"description"];

//4
CGSize textSize = [dealDescription sizeWithFont:fontNormal constrainedToSize:CGSizeMake(containerUIView.frame.size.width, 1000)];

CGRect dealDescRect = CGRectMake(10, 300, containerUIView.frame.size.width, textSize.height);

UITextView *dealDesc = [[[UITextView alloc] initWithFrame:dealDescRect] autorelease];

dealDesc.text = dealDescription;
//add the subview to the container
[containerUIView addSubview:dealDesc];

//1) after adding the view
CGRect frame = dealDesc.frame;
frame.size.height = dealDesc.contentSize.height;
dealDesc.frame = frame;

那就是……干杯