删除storyboard，使用纯代码

1.删除storyboard

2.删除general的main：

3.删除info的main：

4.在Appdelegate.m中加入：

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    
    _window = [[UIWindow alloc]initWithFrame:[UIScreen mainScreen].bounds];
    MasterViewController *master = [[MasterViewController alloc]init];
    _window.rootViewController = master;
    [_window makeKeyAndVisible];
    
    return YES;
}