NSString* text = @"一";

    NSDictionary *attribute = @{NSFontAttributeName: [UIFont systemFontOfSize:16]};

    CGSize size = [text boundingRectWithSize:CGSizeMake(1000, 90) options: NSStringDrawingTruncatesLastVisibleLine | NSStringDrawingUsesLineFragmentOrigin | NSStringDrawingUsesFontLeading attributes:attribute context:nil].size;

    CGFloat w = size.width+2;//一个汉字的宽度加2 ，要不然会显示残缺

    text = @"如题，我们平时习惯的用法是将text以左右顺序呈现在UILabel上，那么有什么方法能让text以上下的顺序显示呢？ ";

    //    CGSize asize = [text sizeWithFont:font constrainedToSize:CGSizeMake(w, MAXFLOAT) lineBreakMode:UILineBreakModeWordWrap];

    //老的方法已经弃用了。

    CGSize asize = [text boundingRectWithSize:CGSizeMake(w, MAXFLOAT) options:NSStringDrawingTruncatesLastVisibleLine | NSStringDrawingUsesFontLeading | NSStringDrawingUsesLineFragmentOrigin attributes:attribute context:nil].size;

    CGFloat h = asize.height;

    UILabel *lable = [[UILabel alloc] initWithFrame:CGRectMake(100,10,w,h)];

    lable.text = text;

    lable.numberOfLines = 0;

    [self.view addSubview:lable];

UILabel垂直方向显示（上下的顺序显示）。