IOS Label 自动换行 IOS6和IOS7

IOS 6和ios7 不一样，所以，我们分开来:

IOS6:

//计算实际frame大小，并将label的frame变成实际大小
    CGSize size01 = [ssizeWithFont:[UIFontsystemFontOfSize:15.0f]constrainedToSize:sizelineBreakMode:NSLineBreakByWordWrapping];

    [label setFrame:CGRectMake(,, size01.width, size01.height)];

IOS7:

 UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(, , , )];
    NSString *str=@"发恶无法奶奶问服务就啃发觉我看能否尽快稳罚款金额为你放假";
    label.text=str;
    UIFont *font=[UIFont systemFontOfSize:];
    label.font=font;

    //拆行
    label.lineBreakMode=NSLineBreakByWordWrapping;
    //设置多行
    [label setNumberOfLines:];

    //设置最大尺寸的宽和高
    CGSize size=CGSizeMake(, );
    //获取当前字体
    NSDictionary *dict=@{NSFontAttributeName: [UIFont systemFontOfSize:]};
    CGSize authSize=[str boundingRectWithSize:size
                                       options:NSStringDrawingUsesLineFragmentOrigin
                                    attributes:dict
                                       context:nil].size;
    label.frame=CGRectMake(, , authSize.width, authSize.height);
    [self.view addSubview:label];