Ios 使用NSMutableAttributeString向UILabel添加填充

我想给突出显示的UILabel添加一些填充（参见屏幕截图）。

我尝试过这样子类化UILabel，但没有成功：

- (id)initWithFrame:(CGRect)frame{
    self = [super initWithFrame:frame];
    if (self) {
        self.edgeInsets = UIEdgeInsetsMake(5, 5, 0, 0); //customize padding here
    }
    return self;
}

- (void)drawTextInRect:(CGRect)rect {
    [super drawTextInRect:UIEdgeInsetsInsetRect(rect, self.edgeInsets)];
}

创建标签的当前函数：

    paddingLabel  *viewTitleLabel = [[paddingLabel alloc]initWithFrame:CGRectMake(view.frame.origin.x, view.frame.origin.y, view.frame.size.width, view.frame.size.height)];

    NSMutableAttributedString *s =
    [[NSMutableAttributedString alloc] initWithString:ticketcode];

    [s addAttribute:NSBackgroundColorAttributeName
              value:[UIColor blackColor]
              range:NSMakeRange(0, s.length)];


    viewTitleLabel.attributedText = s;

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添加填充到标签？你的意思是图像前面需要一些空间？更像是四个侧面的插图