in my viewcontroller,I have a button,when press the button,entry the navigationController,my code like:
-(IBAction)ShangHaiButtonPressed:(id)sender{
marketviewcontroller = [[MarketViewController alloc]initWithNibName:@"MarketViewController" bundle:nil];
NSLog(@"%@",self.navigationController);
[self.navigationController pushViewController:marketviewcontroller animated:YES];
[marketviewcontroller release];
}
but I can see the self.navigationController is null,how to solve this problem?thank you.
update:
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
_switchviewcontroller = [[SwitchViewController alloc]initWithNibName:@"SwitchViewController" bundle:nil];
[self.window addSubview:_switchviewcontroller.view];
[self.window makeKeyAndVisible];
return YES;
}
In AppDelegate.m file make your first view RootView for Navigation :
In your myView.m file add below code to navigate to myNewView from myView :
The navigationController property of a view controller will return a valid navigation controller object only if the view controller is in a navigation controller's navigation stack. A view controller can be added to a navigation stack in the following ways.
By making the view controller the rootViewController of a navigation controller using initWithRootViewController: method of UINavigationController
By pushing the view controller using pushViewController: method of UINavigationController.
Make sure your view controller is added to the navigation stack in any of the above ways.
EDIT: (After the didFinishLaunchingWithOptions: code added to the question):
Change the didFinishLaunchingWithOptions: method to this,
Swift 4 (version):
This code will yield the solution you're looking for: