- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    
    self.window=[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    self.window.backgroundColor=[UIColor whiteColor];
    ViewController* controller=[[ViewController alloc] init];
    UIView* rootView=[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    [rootView setTag:1];
    
    controller.view=rootView;
    self.window.rootViewController=controller;
    
    
    UIButton* button=[UIButton buttonWithType:UIButtonTypeRoundedRect];
    button.frame=CGRectMake(120, 100, 80, 40);
    [button setTitle:@"确定" forState:UIControlStateNormal];
    [button addTarget:self action:@selector(clickHadle:forEvent:) forControlEvents:UIControlEventTouchUpInside];
    [rootView addSubview:button];
    
    UILabel* label=[[UILabel alloc] initWithFrame:CGRectMake(60, 40, 180, 30)];
    [label setText:@"初始文本"];
    [label setTag:11];
    [label setBackgroundColor:[UIColor grayColor]];
    [rootView addSubview:label];
    
    [self.window makeKeyAndVisible];
    
    return YES;
}
就这么多控件,经测试View能显示,View下面的控件显示不出来,空白一片。我用的Xcode6,以下是我项目配置文件