iOS label自适应高度(宽度)

/// label自适应高度(一定要保持字体大小一致, numberOfLines为0, 否则不自适应)
-(CGFloat)setIntroductionText:(NSString*)text label:(UILabel *)label
{
/*boundingRectWithSize: CGSize 对应 constrainedToSize: CGSize
attributes:@{NSFontAttributeName: [ UIFont ] } 对应 sizeWithFont[ UIFont ]
options: NSStringDrawingUsesLineFragmentOrigin 默认照填
context: nil 默认照填 */

CGRect frame = label.frame;
label.numberOfLines = 0;
label.font = [UIFont systemFontOfSize:17.0];

CGSize sizeText =[text boundingRectWithSize:CGSizeMake(KanalysisTitleWhight, 1000) options:NSStringDrawingUsesLineFragmentOrigin attributes:@{NSFontAttributeName:[UIFont systemFontOfSize:17.0]} context:nil].size;

frame.size.height = sizeText.height;

label.frame = frame;

// 返回高度
return sizeText.height;
}