给视图单独加一个方向的边框

代码： CALayer *bottomBorder = [CALayer layer]; bottomBorder.frame = CGRectMake(0.0f, 43.0f, toScrollView.frame.size.width, 1.0f); bottomBorder.backgroundColor = [UIColor colorWithWhite:0.8f alpha:1.0f].CGColor; [toScrollView.layer addSublayer:bottomBorder];