控制器默认空的View

Posted on 2016-07-08 16:15  柠檬片  阅读(84)  评论(0)    收藏  举报 
 1 - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
 2     // Override point for customization after application launch.
 3     
 4     // 1.创建窗口
 5     self.window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];
 6     self.window.backgroundColor = [UIColor yellowColor];
 7     
 8     // 添加按钮
 9     UIButton *btn = [UIButton buttonWithType:UIButtonTypeContactAdd];
10     btn.center = CGPointMake(50, 50);
11     
12     [self.window addSubview:btn];
13     
14     // 2.创建窗口的根控制器
15     // 空:几乎透明,不能穿透
16     ViewController *vc = [[ViewController alloc] init];
17 //    vc.view.backgroundColor = [UIColor clearColor];
18     // 完全透明
19 //    vc.view.alpha = 0;
20     // alpha<=0.01,完全透明,可以穿透
21     vc.view.alpha = 0.01;
22     self.window.rootViewController = vc;
23 //    vc.view.backgroundColor = [UIColor redColor];
24     
25     // 3.显示窗口
26     [self.window makeKeyAndVisible];
27     
28     return YES;
29 }
控制器默认空的View