简单分享一下OC中计算文本高度

参数1 width 或 height 指定一个给出

参数2 

+ (CGFloat)calculateHeight:(Joke *)joke {

    NSDictionary *dictionary = @{NSFontAttributeName:[UIFont systemFontOfSize:17]};

    CGRect rect =  [joke.content boundingRectWithSize:CGSizeMake(kScreenWidth - 2 * kMargin, 0) options:NSStringDrawingUsesFontLeading | NSStringDrawingUsesLineFragmentOrigin attributes:dictionary context:nil];

    return rect.size.height;

}