iOS开发获取UILabel高度

//获取Label高度

-(CGFloat)heightFromString:(NSString*)text withFont:(UIFont*)font constraintToWidth:(CGFloat)width
{
    if (text && font) {
        CGRect rect  = [text boundingRectWithSize:CGSizeMake(width, 1000) options:NSStringDrawingUsesLineFragmentOrigin|NSStringDrawingUsesFontLeading attributes:@{NSFontAttributeName:font} context:nil];
        
        return rect.size.height;
    }
    
    return 0;
}