转载

基本组件的使用——UINavigationController

作用：在多个ViewController中切换。UINavigationController内部以栈的形式维护一组ViewController，

因此，当导航进入一个新视图的时候，会以push的形式将该ViewController压入栈，当需要返回上一层视图的时候则以pop的形式将当前的ViewController弹出栈顶。

先来看一下我们要实现的效果：

然后是代码：

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {  //创建第一个视图  self.firstViewController = [[UIViewController alloc] init];  self.firstViewController.view.backgroundColor = [UIColor whiteColor];  self.firstViewController.title = @"first view";  //在主视图中创建按钮  UIButton *firstBtn = [self createButton:@"to second" target:@selector(push)];  //将按钮添加到视图中  [self.firstViewController.view addSubview:firstBtn];  self.navController = [[UINavigationController alloc]         initWithRootViewController:self.firstViewController];  NSLog(@"%@", self.navController.viewControllers);  NSLog(@"%@", self.firstViewController);  //创建第二个视图  self.secondViewController = [[UIViewController alloc] init];  self.secondViewController.view.backgroundColor = [UIColor whiteColor];  self.secondViewController.title = @"second view";  //在第二个视图中创建按钮  UIButton *secondBtn = [self createButton:@"to first" target:@selector(pop)];  //将按钮添加到第二个视图  [self.secondViewController.view addSubview:secondBtn];  self.window.rootViewController = self.navController;  return YES; } #pragma mark - 自定义方法 - (void)push {  [self.navController pushViewController:self.secondViewController animated:YES]; } - (void)pop {  [self.navController popViewControllerAnimated:YES]; } - (UIButton *)createButton:(NSString *)title target:(SEL)selector {  CGRect btnFrame = CGRectMake(100, 100, 100, 25);  UIButton *button = [UIButton buttonWithType:UIButtonTypeSystem];  [button setFrame:btnFrame];  [button setTitle:title forState:UIControlStateNormal];  [button setBackgroundColor:[UIColor lightGrayColor]];  [button setTitleColor:[UIColor blackColor]        forState:UIControlStateNormal];  [button addTarget:self action:selector     forControlEvents:UIControlEventTouchUpInside];  return button; }