<1> 如果设置导航控制器的根控制器，就会把跟控制器的view添加到导航控制器的View <2> 导航控制器必须要有根控制器
@implementation AppDelegate
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
// Override point for customization after application launch.
self.window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];
// 创建导航控制器的根控制器
UIViewController *vc = [[UIStoryboard storyboardWithName:@"Main" bundle:nil] instantiateInitialViewController];
// 创建导航控制器，设置根控制器
UINavigationController *nav = [[UINavigationController alloc] initWithRootViewController:vc];
/* // 第一个添加的控制器也可以成为导航控制器的根控制器
UINavigationController *nav = [[UINavigationController alloc] init];
[nav pushViewController:vc animated:YES];
*/
self.window.rootViewController = nav;
[self.window makeKeyAndVisible];
return YES;
}
@end2.导航控制器的跳转
<1> 如果一个控制器是导航控制器的子控制器，就可以拿到导航控制器 <2> 导航控制器的viewControllers数组对象保存了所有子控制器 <3> next跳转不能用viewControllers获得控制器对象，因为还没创建 back跳转可以用viewControllers数组获取控制器对象 <4> 跳转到上一个控制器后，此控制器在跳转动画后销毁
@implementation ViewController
- (IBAction)jump2Two:(id)sender {
// init 也会调用initWithNibName: 传入参数为空
// 会去查找View.xib ViewControl.xib ...默认创建
TwoViewController *twoVC = [[TwoViewController alloc] init];
[self.navigationController pushViewController:twoVC animated:YES];
}
- (IBAction)jumpback:(id)sender {
// 跳转到上一个界面调用popViewControllerAnimated
[self.navigationController popViewControllerAnimated:YES];
}
- (IBAction)backRoot:(id)sender { // 回到根控制器
// self.navigationController.viewControllers;
// NSLog(@"%@",self.navigationController.viewControllers);
[self.navigationController popToViewController:self.navigationController.viewControllers[0] animated:YES];
// [self.navigationController popToRootViewControllerAnimated:YES];
}
@end