ipad - dismissing a UIPopoverController

I have a button inside the content of a UIPopoverController. This button runs a method called myAction.

MyAction has the form

- (void) myAction:(id)sender 

so, myAction receives the id of the caller button.

Now, inside this method I would like to dismiss the UIPopoverController,开发者_如何学Go but the only thing I have is the ID of the caller button. Remember that the button is inside the UIPopoverController.

Is there a way to discover the ID of the UIPopoverController, given the button ID I already have?

thanks.

Unfortunately no. At least, not within the standard practices. You might be able to travel up the responder stack to find it, but it's a hack, it's buggy, and it's really, really messy.

If you want to dismiss a popover by pushing a button, some place relevant should keep a reference to the popover. Usually that would be the owner of the popover (not the controller showed within the popover). When the button is pressed, it can send a message to the owner controller, which can then dismiss the popover.

You might be tempted to have the controller displayed inside of the popover be the owner of its own popover, but coding this way is brittle, can get messy (again), and may result in retain loops so that neither ever gets released.

You can access the presenting popoverController by accessing "popoverController" with KVC.

[[self valueForKey:@"popoverController"] dismissPopoverAnimated:YES]

I have this working, and I do not think it is a hack. I have a standard split view iPad app. I then added a method on my detail controller (the owner of the pop over) to handle the dismissal.

On the standard split view architechture, both the root and detail view controllers are available via the app delegate. So I bound a button click inside the pop over to call a method which gets the app delegate. From there I call the method on the detail controller to dismiss the pop over.

This is the code for the method on the View Controller that is displayed inside the popover:

- (void) exitView: (id)sender {
    MyAppDelegate *appDelegate = (MyAppDelegate *)[[UIApplication sharedApplication] delegate];

    [appDelegate.detailViewController exitDrill];
}

Then the simple method to dismiss on the Detail View Controller:

- (void) exitDrill {
    if(dtController != nil){
      [dtController dismissPopoverAnimated: YES];
      [dtController release];
    }
}

I like the ability to do this because it give me a way to show a user how they can exit a pop over. This may not be necessary in future versions of the app; for right now, while this paradigm is still new to the platform, I prefer to let the users gexit a display in a couple fo different ways to make sure I minimize frustration.

As Ed Marty already wrote

If you want to dismiss a popover by pushing a button, some place relevant should keep a reference to the popover

This is very true; however, when showing a UIPopoverController, the class opening the popovercontroller keeps this resource already. So, what you could do is to use this class as the delegate class for your Popover Controller.

To do so, you could do the following, which I use in my code. In the class opening the popover, this is my code:

- (void)showInformationForView:(Booking*)booking frame:(CGRect)rect
{
    BookingDetailsViewController *bookingView = [[BookingDetailsViewController alloc] initWithStyle:UITableViewStyleGrouped booking:booking];
    [bookingView setDelegate:self];

    UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:bookingView];

    self.popController = [[UIPopoverController alloc] initWithContentViewController:navController];
    [self.popController setDelegate:self];
    [self.popController setPopoverContentSize:CGSizeMake(320, 320)];

    rect.size.width = 0;

    [self.popController presentPopoverFromRect:rect inView:self.view permittedArrowDirections:UIPopoverArrowDirectionLeft animated:YES];
}

- (void)dismissPopoverAnimated:(BOOL)animated
{
    [self.popController dismissPopoverAnimated:animated];
}

So what I am doing here is creating a UINavigationController and setting a BookingDetailsViewController as its rootViewController. Then I am also adding the current class as delegate to this BookingDetailsViewController.

The second thing I added is a dismissal method called dismissPopoverAnimated:animated.

In my BookingDetailsViewController.h I added the following code:

[...]
@property (nonatomic, strong) id delegate;
[...]

And in my BookingDetailsViewController.m I added this code:

[...]

@synthesize delegate = _delegate;

- (void)viewDidLoad

{
    UIBarButtonItem *closeButton = [[UIBarButtonItem alloc] initWithTitle:@"Close" style:UIBarButtonItemStylePlain target:self action:@selector(closeView)];
    [self.navigationItem setRightBarButtonItem:closeButton];

    [super viewDidLoad];
}

- (void)closeView
{
    if ([self.delegate respondsToSelector:@selector(dismissPopoverAnimated:)]) {
        [self.delegate dismissPopoverAnimated:YES];
    }
    else {
        NSLog(@"Cannot close the view, nu such dismiss method");
    }
}

[...]

What happens is that when the "Close" button in the UINavigationController is pressed, the method closeView is called. This method check if the delegate responds to dismissPopoverAnimated:animated and if so, it calls it. If it does not respond to this method it will show a log message and do nothing more (so it wont crash).

I have written my code using ARC, hence there is no memory management.

I hope this helped you.