iOS获取字符串高度

/**
@method 获取指定宽度width的字符串在UITextView上的高度
@param textView 待计算的UITextView
@param Width 限制字符串显示区域的宽度
@result float 返回的高度
*/
- (float) heightForString:(UITextView *)textView andWidth:(float)width{
CGSize sizeToFit = [textView sizeThatFits:CGSizeMake(width, MAXFLOAT)];
return sizeToFit.height;
}

UITextView * txtView = [[UITextView alloc] init];
txtView.text = noticeStr;
float strHeight = [self heightForString:txtView andWidth:ScalingWidth(280.0)];