ios 动态计算UITextView的高度

下边两种方法都适用于ios 7.0以后

方法一：

- (CGSize)getStrRectInText:(NSString *)string InTextView:(UITextView *)textView;
{

    //实际textView显示时我们设定的宽
    CGFloat contentWidth = CGRectGetWidth(textView.frame);
    //但事实上内容需要除去显示的边框值
    CGFloat broadWith    = (textView.contentInset.left + textView.contentInset.right
                            + textView.textContainerInset.left
                            + textView.textContainerInset.right
                            + textView.textContainer.lineFragmentPadding/*左边距*/
                            + textView.textContainer.lineFragmentPadding/*右边距*/);

    NSLog(@"broadWith:%f",broadWith);
    CGFloat broadHeight  = (textView.contentInset.top
                            + textView.contentInset.bottom
                            + textView.textContainerInset.top
                            +textView.textContainerInset.bottom);//+self.textview.textContainer.lineFragmentPadding/*top*//*+theTextView.textContainer.lineFragmentPadding*//*there is no bottom padding*/);

    //由于求的是普通字符串产生的Rect来适应textView的宽
    contentWidth -= broadWith;

    CGSize InSize = CGSizeMake(contentWidth, MAXFLOAT);

    NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc]init];
    paragraphStyle.lineBreakMode = textView.textContainer.lineBreakMode;
    NSDictionary *dic = @{NSFontAttributeName:textView.font, NSParagraphStyleAttributeName:[paragraphStyle copy]};

    CGSize calculatedSize =  [string boundingRectWithSize:InSize options:NSStringDrawingUsesLineFragmentOrigin | NSStringDrawingUsesFontLeading attributes:dic context:nil].size;

    CGSize adjustedSize = CGSizeMake(ceilf(calculatedSize.width),calculatedSize.height + broadHeight);//ceilf(calculatedSize.height)
    return adjustedSize;
}

方法二：

- (CGFloat)getHeightForString:(UITextView *)textView andWidth:(CGFloat)width{
    CGSize sizeFit = [textView sizeThatFits:CGSizeMake(width, MAXFLOAT)];
    return sizeFit.height;
}