iOS UITextView根据内容自适应高度

UITextView作为内容文本输入区域，有的时候我们需要根据内容动态改变文本区域的高度，效果如下:

定义UITextView，实现UITextViewDelegate:

-(UITextView *)textView{

if (!_textView) {

_textView=[[UITextView alloc]initWithFrame:CGRectMake(30, 200, CGRectGetWidth([[UIScreen mainScreen] bounds])-60, 30)];

[_textView setTextColor:[UIColor redColor]];

[_textView.layer setBorderColor:[[UIColor blackColor] CGColor]];

[_textView setFont:[UIFont systemFontOfSize:15]];

[_textView.layer setBorderWidth:1.0f];

[_textView setDelegate:self];

}

return _textView;

}

实现textViewDidChange方法:

-(void)textViewDidChange:(UITextView *)textView{

static CGFloat maxHeight =60.0f;

CGRect frame = textView.frame;

CGSize constraintSize = CGSizeMake(frame.size.width, MAXFLOAT);

CGSize size = [textView sizeThatFits:constraintSize];

if (size.height<=frame.size.height) {

size.height=frame.size.height;

}else{

if (size.height >= maxHeight)

{

size.height = maxHeight;

textView.scrollEnabled = YES;  // 允许滚动

}

else

{

textView.scrollEnabled = NO;    // 不允许滚动

}

}

textView.frame = CGRectMake(frame.origin.x, frame.origin.y, frame.size.width, size.height);

}