UIView 自适应

//自适应
UIView backView = [[UIView alloc ]init];
backView.frame = CGRectMake([UIScreen mainScreen].bounds.size.width/2-25,400,50,50 );
backView.tag=1001;
backView.backgroundColor=[UIColor orangeColor];
//准许子视图自适应
backView.autoresizesSubviews = YES;
[self.view addSubview:backView];
UIView topView=[[UIView alloc ]init];
topView.frame =CGRectMake(10, 10, 30, 30);
topView.backgroundColor = [UIColor greenColor];
//设置子视图的适应方式
topView.autoresizingMask =
// UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleRightMargin | UIViewAutoresizingFlexibleTopMargin | UIViewAutoresizingFlexibleBottomMargin|
UIViewAutoresizingFlexibleWidth |UIViewAutoresizingFlexibleHeight;
[backView addSubview:topView];

UIButton *btn = [UIButton buttonWithType:UIButtonTypeSystem];
btn.frame =CGRectMake(10, 550, 355, 30);
btn.backgroundColor = [UIColor lightGrayColor];
[btn addTarget:self action:@selector(btnClick) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:btn];

}

• (void)btnClick
  {
  UIView *view = [self.view viewWithTag:1001];
  view.frame =CGRectMake(view.frame.origin.x-5, view.frame.origin.y-5,view.frame.size.height+10, view.frame.size.width+10);
  }