//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)];

 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];