I think I've done my homework here.
I want my app delegate to be the delegate for my UITabBarController.
Using IB, I've connected UITabBarController's delegate to my Application Delegate.
App Delegate Header file is:
#interface MyAppDelegate : NSObject <UIApplicationDelegate, UITabBarControllerDelegate> {
The delegate method I'm trying to implement is:
-(BOOL)tabBarController:(UITabBarController *)tabBarController shouldSelectViewController:(UIViewController *)viewController {
NSLog(#"shouldSelectViewController called.");
// do some stuff with viewController
return YES;
}
My app delegate has an outlet to the UITabBarController that's connected in IB. When I do this:
NSLog(#"tab bar controller delegate is %#", self.tabBarController.delegate);
I get a good result such as tab bar controller delegate is <MyAppDelegate: 0x6e86a30>.
What am I missing?
Just write this code. Usually in viewDidLoad().
self.tabBarController.delegate = self;
If the current controller is a UITabBarController then:
self.delegate = self
Ok, found the solution. I had some old code in my RootViewController that set up this controller as the delegate. No delegate methods were implemented on the RootViewController, so it appeared as if nothing was happening. Because the RootViewController is set as delegate AFTER MyAppDelegate, the delegate was actually set to the RootViewController.
So the lesson is double-check your code to make sure some other object isn't also being set as the delegate.
Related
I created my iOS app with Tab Bar template, so here is UITabBarController with bar buttons. An issue is how to set it as delegate. I found at SO that it has to be set programmatically in AppDelegate, but I believe it's impossible, because I've got no access to Tab Bar Controller as outlet.
I added proper value to #interface (both ViewController and AppDelegate), but doesn't know what to do next.
#interface ViewController : UIViewController <UITabBarControllerDelegate>
I hope I don't have to get rid of whole app template and it's possible to set Tab Bar Controller created in IB to be delegate.
Exactly I want to make it delegate to create on tab select event like this:
- (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController;
Any idea?
You can quickly and easily create a new TabBarController Delegate class and connect it as the delegate in the storyboard.
Create a new class :
class TabBarControllerDelegate: NSObject, UITabBarControllerDelegate {
In IB, add an object from the object library to the list of View Controller on the left (note: search "object", it's a yellow cube).
Change the class of this object (your yellow cube in IB) to TabBarControllerDelegate
In IB navigate to your Tab Bar Controller Scene. From the Connection Inspector, drag the delegate circle to the new object you added in Step 3.
Implement your delegate methods in your TabBarControllerDelegate class. Done!
func tabBarController(tabBarController: UITabBarController, shouldSelectViewController viewController: UIViewController)->Bool {
println("Selected a new tab")
}
I don't remember exactly the Xcode's Tab Bar template set up, but in your AppDelegate you can access to your window's rootViewController, cast it to a UITabBarController, and then set its delegate to your AppDelegate or to any other view controller.
Something like this:
UITabBarController *tabBarController =
(UITabBarController *)[[self window] rootViewController];
[tabBarController setDelegate:self]; // In this example your app delegate would implement the UITabBarControllerDelegate protocol.
EDIT
If you want to set your ViewController instance as the delegate:
UITabBarController *tabBarController =
(UITabBarController *)[[self window] rootViewController];
// I assume you have your ViewController instance set as the first view controller of your tab bar controller
// No need for a cast here since objectAtIndex: returns id, but of course you must implement the UITabBarController protocol in your ViewController.
[tabBarController setDelegate:[[tabBarController viewControllers] objectAtIndex:0]]];
EDIT 2
From your ViewController itself you can set the tab bar controller's delegate as rdelmar comments.
Just keep in mind that this cannot be done in the init method because the view controller is not in the tab bar controller yet. The proper place would be viewDidLoad but therefore it will not be executed until the ViewController view loads...
self.tabBarController.delegate = self;
0 lines of code
Drag an Object and subclass it
Xcode > Show File Inspector > Custom Class.
Class: TabBarControllerDelegate.
Set delegate to that Object
Put your existing code in that Object
This is the code you already have in your current UITabBarControllerDelegate.
class TabBarControllerDelegate: NSObject, UITabBarControllerDelegate {
// Delegate code goes here
}
What about create a viewController lets say MyTabController subclass UITabBarController
#interface MyTabController : UITabBarController<UITabBarControllerDelegate>
and set the tab Controller's class in you storyboard to MyTabController instead of UITabBarController, then put self.delegate = self; in your viewDidLoad
implement:
- (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController;
and here you are.
Edit:
If you find self.delegate = self; is odd, which it is, you can create an outlet in your MyTabController
IBOutlet UITabBarController *tabBarController; and connect it to the tab controller in your storyboard.
Then you can put tabBarController.delegate = self;
I'm having a problem using the Facebook SLComposeViewController in a UIView. The problem I'm having is because I have a UIView and not a UIViewController that I'm inheriting from.
I've imported:
#import <Social/Social.h>
#import <Accounts/Accounts.h>
and am trying to present the Facebook sharing using:
SLComposeViewController *controllerSLC = [SLComposeViewController composeViewControllerForServiceType:SLServiceTypeFacebook];
[controllerSLC setInitialText:#"First post from my iPhone app"];
[controllerSLC addURL:[NSURL URLWithString:#"http://www.test.com"]];
[controllerSLC addImage:[UIImage imageNamed:#"test.jpg"]];
[self presentViewController:controllerSLC animated:YES completion:Nil];
It's the last line it won't present the view because I'm inheriting from UIView and not UIVIewController I'm not sure how to fix this. I just want to share an image.
thanks for any help.
UIViews cannot present view controllers. You'll need to set up a way to call back to the UIViewController that is presenting to your UIView.
A common way would be to make create a delegate on your view. When something happens on that view, the delegate method is called which messages the view controller that implements your delegate methods. From there, you can present the view controller from your parent view controller.
In your view's .h file:
#protocol YourUIViewDelegate <NSObject>
- (void)theDelegateMethod;
#end
#interface YourUIView : UIView
#property (assign, nonatomic) id<YourUIViewDelegate> delegate;
In your view's .m file (I'm assuming there's a button press or some other action method that gets called where you want to present this view controller):
- (void)buttonTapped:(id)sender
{
[self.delegate theDelegateMethod];
}
In the view controller .h that is presenting the delegate method:
#interface ThePresentingViewController <YourUIViewDelegate>
In that view controller's .m file:
- (void)theDelegateMethod
{
// All of the SLComposeViewController code
}
Don't forget to set the view's delegate to the view controller within the presenting view controller.
I have a UIViewController called ShowListViewController that uses a Modal View Controller to push another view onto the stack:
AddShowViewController *addShowViewController = [[AddShowViewController alloc] init];
[addShowViewController setModalTransitionStyle:UIModalTransitionStyleCoverVertical];
[self presentModalViewController:addShowViewController animated:YES];
I would then like to call my method populateTableData of the ShowListViewController class when the addShowViewController disappears.
I would think that the answer found here would work, but it doesn't. My method populateTableData is not detected as an optional method to use.
Essentially my questions is: How do I detect when a Modal View Controller disappears so as to call a method within the class that pushed it on the stack?
This may not be a best solution, but can do what you want at this time.
In your showlistcontroller add an instance variable like
BOOL pushedView;
#implementation ShowListViewController
and before you do the modal presentation set its values as YES like
pushedView = YES;
[self.navigationController presentModalViewController:popView animated:YES];
in the viewWillAppear of ShowListViewController you can detect whether it is appearing because pop getting dismissed or not like
if (pushedView) {
NSLog(#"Do things you would like to on pop dismissal");
pushedView = NO;
}
I think you would like something like this.
You make a delegate inside ur modalVC like this:
#protocol ModalViewDelegate <NSObject>
- (void)didDismissModalView;
#end
and implement it in your MainVC like this:
#interface MainViewController : UIViewController <ModalViewDelegate>
{
Then u will make a delegate property in your modalVC like this:
#interface ModalShizzle : UIViewController
{
id<ModalViewDelegate> dismissDelegate;
}
You set the dismissDelegate of your ModalVC to your MainVC and then you make the delegate method. Before you dismiss it however you will call the ModalVC to do one last thing. (which is populate your table). You will call for the data inside your MainVC and then do whatever you feel like it, just before you dismissed your modalVC.
-(void)didDismissModalView
{
//call ModalVC data here...
//then do something with that data. set it to a property inside this MainVC or call a method with it.
//method/data from modalVC is called here and now u can safely dismiss modalVC
[self dismissModalViewControllerAnimated:YES];
}
Hope it helps ;)
OK so it appears that in Apple's template for Utility App's they ignore what the docs for [UIViewController][1] say and actually go out of their way to call dismissModalViewControllerAnimated: from the UIViewController that pushed the modal view onto screen.
The basic idea in your case will be
Define a protocol for AddShowViewControllerDelegate
Make ShowListViewController implement this protocol
Call a method on the delegate to ask it to dimiss the modal view controller
For a full example just create a new project with Utility template and look at the source for FlipsideViewController and MainViewController
Here is an example adapted for your needs:
AddShowViewController.h
#class AddShowViewController;
#protocol AddShowViewControllerDelegate
- (void)addShowViewControllerDidFinish:(AddShowViewController *)controller;
#end
#interface AddShowViewController : UIViewController
#property (nonatomic, assign) id <AddShowViewControllerDelegate> delegate;
- (IBAction)done:(id)sender;
#end
AddShowViewController.m
- (IBAction)done:(id)sender
{
[self.delegate addShowViewControllerDidFinish:self];
}
ShowListViewController.h
#interface ShowListViewController : UIViewController <AddShowViewControllerDelegate>
{
...
}
ShowListViewController.m
- (void)addShowViewControllerDidFinish:(AddShowViewController *)controller
{
[self dismissModalViewControllerAnimated:YES];
[self populateTableData];
}
I have a UITabController in my main window, and would like to add some logic when each tab is selected. I've added the delegate to the header file:
#interface MyAppAppDelegate : NSObject <UIApplicationDelegate, UITabBarDelegate> {
I have a method for the tab change event:
- (void)tabBar:(UITabBar *)tabBar didSelectItem:(UITabBarItem *)item{
//some code
}
But the code inside the didSelectItem method isn't called. I've connected the delegate for the UITabBarController to my AppDelegate in IB. Is there anything else I need to do?
If you assign the delegate via IB, you should connect the delegate for your TabBar (as opposed to your TabBarController) to your app delegate.
Indeed, you are not looking for the UITabBarControllerDelegate, but for the UITabBarDelegate.
If you do it programmatically, then, from your tab bar controller viewDidLoad execute:
self.tabBar.delegate = [UIApplication sharedApplication].delegate;
If you use UITabbarController you can use UITabBarControllerDelegate instead of UITabBarDelegate.
Then, you can set self.delegate = self. Then you use:
(void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController;
instead of:
(void)tabBar:(UITabBar *)tabBar didSelectItem:(UITabBarItem *)item;
Did you assign some class to be the tab bar's delegate? Something like
myTabBar.delegate = self;
i might be out on a ledge here but i think the signature of the method should be:
- (IBAction)tabBar:(UITabBar *)tabBar didSelectItem:(UITabBarItem *)item
and then you connect it to the tabbar in IB. after you change to IBAction it should appear in IB
I ended up putting it in the viewWillAppear method of the view in the specific tab I need. Seems to work fine.
Can any one help me,
when i am using my UITabBarController delegate it is not working..
I called a delegate method like this..
- (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController
{
[self.navigationController popToRootViewControllerAnimated:NO];
}
If what you're doing is subclassing a UITabBarController, then... oddly enough... you can get it working by setting itself as a delegate:
- (void)viewDidLoad
{
[super viewDidLoad];
self.delegate = self;
}
Then the didSelectViewController action will fire normally:
- (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController {
NSLog(#"View Changed");
}
Don't forget to add your UITabBarControllerDelegate class to your .h file:
#interface MyTabBarController : UITabBarController <UITabBarControllerDelegate>
#end
If you are using tab bar customizing by extending UITabBarController and trying to change tab bar selected index programmatically then it will not call delegates.
Please see the note inside "UITabBarDelegate":
// Note: called when a new view is selected by the user (but not programmatically)
This might help you
-(void)applicationDidFinishLaunching:(UIApplication *)application {
tabBarController.delegate=self;
// Add the tab bar controller's current view as a subview of the window
[window addSubview:tabBarController.view];
}
specify
UITabbarcontrollerDelegate in .h file
then
-(void)applicationDidFinishLaunching:(UIApplication *)application {
tabBarController.delegate=self;
// Add the tab bar controller's current view as a subview of the window
[window addSubview:tabBarController.view];
}
Read the documents to get a deeper understanding of the relationships between navigation controllers, tabBar controllers, and the view and navigation hierarchy.
Then review the code you've provided. Which view/controller is the container? You are popping the navigationController of self, which is not the same as the tabBarController. I don't think you actually need this method if you are looking to switch between tabs.
Try commenting out this method. It is an optional method in the UITabBarController delegate protocol. If you comment it out, you should get the default behavior of the tab controller, which should be to select the appropriate viewController and switch to the new view.
You typically only need to use this method if you want some action taken as you switch between view controllers.