IOS頁面跳轉的方法

在頁面跳轉時，若想用pushViewController，則必須在AppDelegate設置UINavigationController，否則pushViewController無效。
並且用pushViewController從A跳往B后，在B頁面自帶“Back”按鈕返回上一頁。類似於

這樣設置，在AppDelegate中

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    self.window = [[UIWindow alloc]initWithFrame:[[UIScreen mainScreen] bounds]];
    UIViewController *controllerA = [[ViewController alloc]init];
    UINavigationController *nav = [[UINavigationController alloc] initWithRootViewController:controllerA];
    
    self.window.rootViewController = nav;
    [self.window makeKeyAndVisible];
    
    return YES;
}

在controllerA中的跳轉頁面方法中這樣寫

-(void)turnToOtherController{
    ControllerB *controllerB = [[ControllerB alloc]init];
    [self.navigationController pushViewController:controllerB animated:YES];
}

這樣，導航條就會一直存在。若不想要導航條，那么在AppDelegate這樣寫

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    self.window = [[UIWindow alloc]initWithFrame:[[UIScreen mainScreen] bounds]];
    UIViewController *controllerA = [[ViewController alloc]init];
    self.window.rootViewController = controllerA;
    [self.window makeKeyAndVisible];
    
    return YES;
}

而下面這種方法是通用的，無需設置rootViewController。

[self presentViewController:mainView animated:YES completion:nil];//controller自帶的屬性

下面的則需要

[self.navigationController pushViewController:mainView animated:YES];
//必須在AppDelegate設置UINavigationController，否則pushViewController無效。
//並且使用pushViewController后，在B頁面，會自帶一個“Back”按鈕返回上一頁。