子视图是以栈的方式存放的,也就是说有层次的存放
addSubview:
addsubview时都是在最上面面添加
eg: <pre> UIView*v1 = [UIViewnew];
v1.frame= CGRectMake(100,100,100,60);
v1.backgroundColor= [UIColorredColor];UIView*v2 = [UIViewnew];
v2.backgroundColor= [UIColorpurpleColor];
v2.frame= CGRectMake(80,120,100,60);
[self.viewaddSubview:v1];
[self.viewaddSubview:v2]; </pre> 看到如下效果
pic1
insertSubview
insertSubView可以控制将view添加到指定的层
eg: <pre> UIView*v1 = [UIViewnew];
v1.frame= CGRectMake(100,100,100,60);
v1.backgroundColor= [UIColorredColor];UIView*v2 = [UIViewnew];
v2.backgroundColor= [UIColorpurpleColor];
v2.frame= CGRectMake(80,120,100,60);
[self.viewaddSubview:v1];
[self.viewaddSubview:v2];UIView*v3 = [UIViewnew];
v3.backgroundColor= [UIColoryellowColor];
v3.frame= CGRectMake(60,140,160,60);
[self.viewinsertSubview:v3 atIndex:3]; </pre>
pic2
可以看到v3在v1跟v2之间,按照我们的打算,atIndex:3 应该是在第四层,而现在感觉不像,我们可以打印一下看下究竟: <pre> NSLog(@"%@",self.view.subviews); </pre> 打印如下: <pre>
( "<_UILayoutGuide: 0x7f8893602e80; frame = (0 0; 0 0); hidden = YES; layer = <CALayer: 0x60800003e220>>", "<_UILayoutGuide: 0x7f8893609080; frame = (0 0; 0 0); hidden = YES; layer = <CALayer: 0x60800003e080>>", "<UIView: 0x7f8893406ab0; frame = (100 100; 100 60); layer = <CALayer: 0x60000003de40>>", "<UIView: 0x7f8893407270; frame = (60 140; 160 60); layer = <CALayer: 0x60000003dc00>>", "<UIView: 0x7f8893407c60; frame = (80 120; 100 60); layer = <CALayer: 0x60000003de60>>" ) </pre> 可以看到v1之前,也就是self.view有两层,v1 index就是2, v2的为4,v3 插在 index:3 ,所以在v1跟v2之间。
可以看到:
<pre>[self.view addSubView:xx.view] </code>其实就等于<code>[self.view insertSubView:xx.view atIndex:[self.view.subViews count]];</pre>
即在最顶层添加view。