先上图:
我是自己定义的tabbar
UIImageView * backImageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, -13, mScreenWidth, 62)];
backImageView.image = [UIImage imageNamed:@"tabbar"];
[self addSubview:backImageView];
不是自己定义的可以用 [UITabBar appearance]来添加
效果图: