Question

ios 判断view是否有子视图

Answer 1

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for (int>0;>3; i++) {

UIView *v = [[UIView alloc] initWithFrame:CGRectMake(30*i, 30*i+50, 80, 80)];

v.backgroundColor =[[UIColor alloc] initWithRed:arc4random()%256/255.0 green:arc4random()%256/255.0 blue:arc4random()%256/255.0 alpha:arc4random()%1001/999.0];

[self.window addSubview:v];

[v release];

}

UIView *v =[[UIView alloc] initWithFrame:CGRectMake(20, 20, 20, 80)];

v.backgroundColor =[UIColor yellowColor];

//插入子视图 index就是数组的下标 （实际上是在self.window.subview 视图中添加子视图）

[self.window insertSubview:v atIndex:1];

//插入子视图 放在某视图上面

UIView *v1 =[[UIView alloc] initWithFrame:CGRectMake(40, 20, 20, 70)];

v1.backgroundColor = [UIColor orangeColor];

[self.window insertSubview:v1 aboveSubview:self.window.subviews[2]];

//插入子视图 放在某视图下面

UIView *v2 =[[UIView alloc] initWithFrame:CGRectMake(0, 20, 20, 100)];

v2.backgroundColor = [UIColor greenColor];

[self.window insertSubview:v2 belowSubview:self.window.subviews[0]];

//把某视图置顶（不进行插入）调用完毕后 该视图在最顶层

[self.window bringSubviewToFront:self.window.subviews[3]];

//把某视图置底（不进行插入）调用完毕后 盖世兔在最底层

[self.window sendSubviewToBack:self.window.subviews[5]];

//某视图交换位置后 索引值也会发生变化

//把某个视图调换位置

[self.window exchangeSubviewAtIndex:0 withSubviewAtIndex:4];

//判断视图是否是另一个视图的子视图

NSLog(@"%d",[self.window.subviews[0] isDescendantOfView:self.window]);

Answer 2

{ //1 创建scrollView CGFloat scrollViewWidth = 600;//scrollView宽度 CGFloat scrollViewHeight = 200;//scrollView高度 UIScrollView *scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 40, scrollViewWidth, scrollViewHeight)]; //2 将scrollView添加到当前视图 [view addSubview:scrollView]; //3 在scrollView中添加子视图 UIView *subView1 = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 200, scrollViewHeight)]; subView1.backgroundColor = [UIColor redColor]; [scrollView addSubview:subView1]; UIView *subView2 = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 200, scrollViewHeight)]; subView2.backgroundColor = [UIColor greenColor]; [scrollView addSubview:subView2]; UIView *subView3 = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 200, scrollViewHeight)]; subView2.backgroundColor = [UIColor greenColor]; [scrollView addSubview:subView2]; }