title: How to limit the width and height in UITextView?
body: <p>I want to make a UITextView which have a maximum width and a minimum height.Just like chat bubble in "message" App in our iPhone.
  I tryed to use <strong>sizeThatFits</strong>.But it didn't give me a wonderful size.</p>
  
  <pre><code>NSString *string = @"hello everyone";
  _textView = [[UITextView alloc] init];
  _textView.font = [UIFont systemFontOfSize:16];
  _textView.text = string;
  [self.view addSubview:_textView];
  
  CGSize size = [string sizeWithAttributes:@{NSFontAttributeName:[UIFont systemFontOfSize:16]}];
  CGFloat finalWidth = MIN(250, size.width);
  CGSize constraintSize = CGSizeMake(finalWidth, MAXFLOAT);
  CGSize finalSize = [_textView sizeThatFits:constraintSize];
  _textView.frame = CGRectMake(0, 0, finalSize.width, finalSize.height);
  </code></pre>
  
  <p>I know there are something wrong with my code.So I wonder a good way to limit the width and height in UITextView correctly.
      Thanks    </p>
  
  <hr>
  
  <p>some friends tell me to use Autolayout.Then I try to do it.Here is my code</p>
  
  <pre><code>   [_textView mas_makeConstraints:^(MASConstraintMaker *maker){
      maker.right.equalTo(self.mas_left);
      maker.top.equalTo(self.mas_top);
      maker.width.lessThanOrEqualTo(@(250));
      maker.height.greaterThanOrEqualTo(@(40));
  }];
  </code></pre>
  
  <p>But it doesn't work unless I use <strong>[_textView sizeToFit]</strong>
  Is there anything wrong with my constraints? I want textView adjust itself according to its content!</p>