更改哪个视图首先打开（Xcode）

Question

  

可能重复：
  How to change the default View Controller that is loaded when app launches?

因此，如果我创建了一个应用程序并且默认情况下首先打开某个视图，并且决定我要更改哪个视图首先打开，我该怎么做？

Answer 1

这是在AppDelegate.m文件中的方法（或应用程序委托文件的标题）中控制的，名为didFinishLaunchingWithOptions。例如，在我创建的标签栏应用程序中，它看起来像这样：

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    // Override point for customization after application launch.
    // Add the tab bar controller's current view as a subview of the window

    self.window.rootViewController = self.tabBarController;
    [self.window makeKeyAndVisible];
    return YES;
}

您所要做的就是更改self.window.rootViewController的值。例如，假设您希望MapViewController成为第一个打开的页面。你可以这样做：

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    // Override point for customization after application launch.
    // Add the tab bar controller's current view as a subview of the window
    MapViewController *mvc = [[MapViewController alloc]initWithNibName:@"MapViewController" bundle:nil]; //Allocate the View Controller

    self.window.rootViewController = mvc;   //Set the view controller
    [self.window makeKeyAndVisible];  
    [mvc release];    //Release the memory
    return YES;
}