I want to do this simple thing: create a uinavigationcontroller but that doesnt show up on launch. Let's say I want to have a welcome screen with a "Go" button that leads to the uinavigationcontroller. In all the examples that I have seen it looks like the navigationcontroller appears right away. How should I go about doing that?
Thanks!
If by "show up" you mean using a navigation controller with no visible footprint, that's easy. Simply do this in the root view controller:
// Root
- (void)viewWillAppear:(BOOL)animated
{
[self.navigationController setNavigationBarHidden:YES animated:animated];
}
For the child view controllers, you need to do something similar in order to display the navigation bar when they appear.
// Child
- (void)viewWillAppear:(BOOL)animated
{
[self.navigationController setNavigationBarHidden:NO animated:animated];
}
This is a pretty common technique for apps with main menus where you don't want to display a navigation bar in the main menu view.
The mecanic of displaying the navigation controller's view takes place in the -(BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions; method, in the app delegate. There the NC is added as the rootViewController of the window.
If you want to display another one, just set your custom view controller right in place of the NC and then switch the two view controllers (replace the first custom view controller with the NC) in the action method called when the button is pressed.
Assuming myCustomController defines a UIButton property called touchButton :
// in the app delegate
-(BOOL)application:(UIApplication *)application
didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
//self.window.rootViewController = self.navigationController;
[self.myCustomController.touchButton addTarget:self
action:#selector(switchVC)
forControlEvents:UIControlEventTouchUpInside];
self.window.rootViewController = self.myCustomController;
[self.window makeKeyAndVisible];
return YES;
}
Now write in your app delegate an action method :
-(void)switchVC {
self.window.rootViewController = self.navigationController;
}
in viewcontroller that shows go hide navigation bar and in other show navigation bar
[self.navigationController setNavigationBarHidden:YES];
hope this will help
Related
I am very new to iPhone world. I am working on a view based project.MY first view have login page. when login is successful it moves to next view.
What i want to implement is that when i will be at second view. There will be a tabbarcontroller which have five tab items and first tab's view will be visisble. When i click other tabs, we will get next views accordingly.
Now, How to place a tab bar in second view only ?
Any kind of help will be highly appreciated.
Use [self presentModalViewController to show the login controller over your tabbar controller. After successfull login, just dismiss it.
You would need to create a ViewController which is a subclass of UITabBarViewController. Design the tabbar in nib or view lifecycle method of this controller.
After login present the new controller as [self presentModalViewController]
You need to implement your code as below.
First create a controller class for login.
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
[self generateLoginScreen];
[self removeLoginScreen]; // On login check implement this method or u can directly write the snippet here as well.
[self prepareControllersOnTabs]; //your tab controller code function
[self.window makeKeyAndVisible];
return YES;
}
-(void) removeLoginScreen
{
[loginScreenViewController.view removeFromSuperview];
self.window.rootViewController = self.tabBarController;
[loginScreenViewController release];
}
-(void) generateLoginScreen
{
loginScreenViewController = [[LoginScreenController alloc] initWithNibName:#"LoginScreenController" bundle:[NSBundle mainBundle]];
[self.window addSubview:self.loginScreenViewController.view];
}
Hope this is exactly what u want.
Before:
My App is based on indepent view controllers. I can switch from one to another by replacing the root view controller on the application delegate:
ade.window.rootViewController = newController;
... and all worked right, till now.
Tomorrow:
we have to add a NavigationController-based part of our App, which will help the users navigate through our:
Brands => Model Names => Colors
So, the user will choose a color, then click a button: now I will switch to another UIViewController (call it "pippo"), which actually resides outside that navigation hierarchy (I can't push it in the nav-controller for several methods, I'm forced doing so!).
What I want is to get back to my "Color" screen, from "pippo". So, I'm looking for a way to programmatically "navigate" the navigation controller I restore, I mean:
I restore my navigation controller
now I'm on Brands, but I don't want my users to be here, I want to show them the last color they was on (I saved it in the preferences)
how can I simulate the selection of a known brand and model?
Thanks a lot.
In applicationDidFinishLoading in App delegate:
UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:rootViewController];
[window makeKeyAndVisible];
[window addSubview:navController.view];
That will instantiate the navigation controller and add it to the window as a view.
Now, in your rootViewController class (lets say its called FirstViewController) you can do this:
- (void)clickedAButton:(id)selector {
SecondViewController *nextViewController = [[SecondViewController alloc] initWithNibName:nil bundle:nil];
// and push it onto the 'navigation stack'
[self.navigationController pushNavigationController:nextViewController animated:YES];
// and release
[nextViewController release];
}
And in your SecondViewController you can navigate back through the stack using:
- (void)clickedAnotherButton:(id)selector {
// goes back to the last view controller in the stack
[self.navigationController popViewControllerAnimated:YES];
}
So for you it would go:
Set up navigation controller in the app delegate with Brand as the root view controller
User chooses their brand and you pushViewController:animated: the Model view controller. Then the user chooses their model and you pushViewController:animated: the Color view controller. Similarly the user chooses a color and you push the Pippo view controller. Now, if the user presses back (or you call popViewControllerAnimated:) it will go back to the Color view controller in the same state as when the user left it to go to the Pippo controller.
Write the following code in AppDelegate.m Class
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
MainViewController *mainViewController = [[MainViewController alloc] initWithNibName:#"MainViewController" bundle:nil];
self.nav = [[UINavigationController alloc] initWithRootViewController:mainViewController];
self.nav.navigationBarHidden = YES;
[mainViewController release];
[_window addSubview:nav.view];
[_window makeKeyAndVisible];
}
I have an iPhone application with 2 tabs. This is my application delegate:
(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;
}
My first tab is a subclass of UITableViewController. I would like to push a new view controller when someone clicks on a row of my table. I know that this is done in didSelectRowAtIndexPath like this:
TableViewDetailViewController *fvController = [[TableViewDetailViewController alloc] initWithNibName:#"TableViewDetailViewController" bundle:[NSBundle mainBundle]];
[self.navigationController pushViewController:fvController animated:YES];
[fvController release];
fvController = nil;
My self.navigationController is NIL so nothing gets pushed to the view stack. Where should I create my navigationController, so there would be as little code to change as possible?
We have direct solution using Interface builder.
In interface builder go to xib in which you have added tabBarController and delete the tabBarItem with which you have connected your tableViewController .
Now, drag and drop an UINavigationController from library in your tabBar and set this navigationController's rootViewController as your tableViewController.
Thanks
Instead of setting your TableViewDetailViewController as one of your tabbbars ViewControllers, you should create an UINavigationController for each tab on your tabbar. Then place your TableViewDetailViewController inside the corresponding UINavigationController. self.navigationController will point to a valid UINavigationController in that case.
I have a tabBarController that I add by placing the following code into:
AppDelegate.h:
...
UITabBarController IBOutlet *tabBarController;
}
#property (nonatomic, retain) IBOutlet UITabBarController *tabBarController;
AppDelegate.m:
...
[self.window addSubview:tabBarController.view];
[self.window makeKeyAndVisible];
[tabBarController setDelegate:self];
I then use the following code to present a modal barcode scanning View Controller:
- (void)tabBarController:(UITabBarController *)tbc didSelectViewController:(UIViewController *)vc {
// Middle tab bar item in question.
if (vc == [tabBarController.viewControllers objectAtIndex:2]) {
ScanVC *scanView = [[ScanVC alloc] initWithNibName:#"ScanViewController" bundle:nil];
// set properties of scanView's ivars, etc
UINavigationController *navigationController = [[UINavigationController alloc] initWithRootViewController:scanView];
[tabBarController presentModalViewController:navigationController animated:YES];
[navigationController release];
[scanView release];
}
}
When it does actually get presented I think this method isn't visually appealing, because when I dismiss the modal view I am brought back to an empty view.
A lot of barcode scanning applications or applications that simply display an image picker for example; do this quite successfully. I'm just wondering what kind of implementation they would use in order to achieve such an effect.
This is a screenshot of an application called Path, which has the exact same functionality I'm after:
I also noticed that in these applications, if you are on any other tab bar item other than the middle one let's say, and you click on the tab bar item that presents the modal view, once it gets dismissed it doesn't actually bring them back to an empty view it dismisses like normal, however the actual tab bar item that presents the modal view is never selected. I would be happy with this type of functionality if that's the only way to implement this type of effect.
Any help would be greatly appreciated as I've been stuck in this for quite some time. Also I'm not even sure whether it's the right way to put all of this code in my AppDelegate in order for the View Controller to be presented as a modal. It all seems, just, wrong.
Not entirely what I'm after, but I think I can move forward from this:
http://idevrecipes.com/2010/12/16/raised-center-tab-bar-button/
When you dismiss the modal view controller, tell the tab bar to select whatever tab was originally selected.
- (void)dismissModalViewControllerAnimated:(BOOL)animated
{
// do whatever you need to do when dismissing
// savedTabIndex is an int ivar
// tabBarController is a reference, set when showing the modal view
[[self tabBarController] setSelectedIndex:savedTabIndex];
}
You would have to save the original tab bar selection in a variable at the start of tabBarController:didSelectViewController:.
- (void)tabBarController:(UITabBarController *)tbc
didSelectViewController:(UIViewController *)vc
{
// Save the tab bar index (if it's not the photo tab)
if ([tabBarController selectedIndex] != 3]) {
savedTabIndex = [tabBarController selectedIndex];
}
}
There could be mistakes in this code, I just typed it without testing.
I found a really easy solution by playing around UITabBarControllerDelegate--I only tried this in iOS 7 though.
First, subclass UITabBarController, make it its own UITabBarControllerDelegate, and create a property that'll hold a reference to the tab you want to launch a modal with. In my app, it's called the "Sell" tab.
#property (strong, nonatomic) UIViewController *sellTab;
Then, in your init method, just create that view controller and add it to the tabs.
_sellTab = [[UIViewController alloc] init];
_sellTab.title = #"Sell";
self.viewControllers = #[homeTab, historyTab, _sellTab, bookmarksTab, profileTab];
Now here's where the magic is: override the following tab bar controller delegate methods. Code is pretty self-explanatory.
#pragma mark - Tab bar controller delegate
- (BOOL)tabBarController:(UITabBarController *)tabBarController shouldSelectViewController:(UIViewController *)viewController
{
return viewController != self.sellTab;
}
- (void)tabBar:(UITabBar *)tabBar didSelectItem:(UITabBarItem *)item
{
if (item == self.sellTab.tabBarItem) {
[self presentViewController:[[UINavigationController alloc] initWithRootViewController:[[PostAdViewController alloc] init]] animated:YES completion:nil];
}
}
This will launch a modal which, upon dismissal, shows the same tab you were in before launch.
You shouldn't present a modal view, when the user clicks on a tab bar item.
You could instead present a modal view from within a view that's presented by one of the tabs.
Or, if you just have a single main view and the scan view you want to present modally, you should just use a button to present the scan view from within your main view. You could for instance use a toolbar with a single button in it, instead.
I am creating an application which I want to have a view controller with buttons as the first view controller with no navigation bar, and then when the user selects a button a table view controller appears managed by a navigation controller.
At the moment I am setting up the navigation controller in the app delegate and setting the top view controller as the table view controller I want to start the navigation bar on. So far I can see the navigation bar but that is it when I transition from the first view controller to the table view controller.
Any help would be much appreciated as I have confused myself with this issue.
I'm not totally clear on what you are asking, so I might have it wrong, but here goes.
The top navigation bar is can be displayed or hidden by calling:
self.navigationController.navigationBarHidden = NO;
In the viewWillAppear method of your viewController. So set it to YES or NO depending on whether or not you want it to be displayed.
#Disco, you would do something like so:
// In the App delegate
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
CustomViewController *viewController = [[CustomViewController alloc] init];
[window addSubview:viewController.view];
[window makeKeyAndVisible];
return YES;
}
// In your button method
- (IBAction)loadUpTableViewController:(id)sender {
CustomTableViewController *tvc = [[CustomTableViewController alloc] init];
UINavigationController *navigationController = [[UINavigationController alloc] initWithRootViewController:tvc];
[self presentModalViewController:navigationController animated:YES];
[navigationController release];
[tvc release];
}