Presenting a Modal View Controller hides the Navig

问题:

I have a navigation based app with a navigation bar, but there are a few instances where instead of pushing a view controller onto the stack, I need to present the view controller modally. The problem is that when I dismiss the modal view controller, everything functions as expected except that the navigation bar is hidden and the (parent view) has been resized, which is the expected behavior according to the docs. So I figured I could simply call a built-in method to unhide the navigation bar. I have already tried

[self.navigationController setNavigationBarHidden:NO];

as well as the animated version without success.

The documentation talks about this in the method

presentModalViewController: animated:

in the discussion section where it says,

On iPhone and iPod touch devices, the view of modalViewController is always presented full screen" and "Sets the modalViewController property to the specified view controller. Resizes its view and attaches it to the view hierarchy."However, the docs didn't clue me in as to how to undo this process after dismissing a modal view.

Has anyone else experienced this and found a solution?

Edit: I am having this same problem, so instead of asking my own question I am sponsoring a bounty on this one. This is my specific situation:

In my case, I am presenting an Image Picker in a Modal View Controller, over a Navigation Controller:

-(void) chooseImage {
    if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary]) {
        imagepicker = [[UIImagePickerController alloc] init];
        imagepicker.allowsEditing = NO;
        imagepicker.delegate = self;
        imagepicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
        imagepicker.navigationBar.opaque = true;
        imagepicker.wantsFullScreenLayout = NO;

        if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) {

            if (self.view.window != nil) {
                popoverController = [[UIPopoverController alloc] initWithContentViewController:imagepicker];

                [popoverController presentPopoverFromBarButtonItem:reset permittedArrowDirections:UIPopoverArrowDirectionDown animated:YES];
            } else {}

        } else {
            [self.navigationController presentModalViewController:imagepicker animated:YES];   
        }
    }
}

-(void) imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
    if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) {
        [self.popoverController dismissPopoverAnimated:true];
    } else {
        [self.navigationController dismissModalViewControllerAnimated:YES];
    }
    //Save the image
}

-(void) imagePickerControllerDidCancel:(UIImagePickerController *)picker {
    if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) {
        [self.popoverController dismissPopoverAnimated:true];
    } else {
        [self.navigationController dismissModalViewControllerAnimated:YES];
    }
}

回答1:

Make sure you a presenting AND dismissing the modalViewController from the UINavigationController, like so:

// show
[self.navigationController presentModalViewController:vc animated:YES];
// dismiss
[self.navigationController dismissModalViewControllerAnimated:YES];

If your view controller is actually on the UINavigationController's stack then this is the correct way to handle the presentation and dismissal of the modal view controller. If your UINavigationBar is still hidden, there is something else funky going on and we would need to see your code to determine what is happening.

Edit

I copied your code into an app of mine and the UIImagePickerController successfully presented and dismissed and my UINavigationController's UINavigationBar was still there. I truly believe that the problem lays elsewhere in your architecture. If you upload a zip w/ an example project I will take a look.

回答2:

Simply try following code it will work

SettingsViewController *settings    =   [[SettingsViewController alloc] init];
UINavigationController *navcont = [[UINavigationController alloc] initWithRootViewController:settings];
[self presentModalViewController:navcont animated:YES];
[settings release];
[navcont release];

One need to present the navigation controller in order to have navigation bar on the presented controller

回答3:

I think I've seen this behavior when presenting a view controller on the wrong VC. Are you calling presentModalViewController on the navigation controller or the individual VC?

Try calling it from the navigationController if you aren't already.

[self.navigationController presentModalViewController:myVC animated:YES];

回答4:

If you present a controller as model, View controller will appear to total view.

If you want to access the navigation controller properties over the model view, You need to create another navigation controller reference and it continues as previous.

This may be useful for you.

回答5:

Check this out. This is Apple's Documentation under UIViewController Class Reference:

It clearly mentions that modal view always presents in full screen mode, so it is obvious that navigation bar will be hidden. So put the seperate navigation bar on modal view to navigate back.

presentModalViewController:animated:
Presents a modal view managed by the given view controller to the user.

- (void)presentModalViewController:(UIViewController *)modalViewController animated:(BOOL)animated
Parameters
modalViewController
The view controller that manages the modal view.
animated
If YES, animates the view as it’s presented; otherwise, does not.
Discussion
On iPhone and iPod touch devices, the view of modalViewController is always presented full screen. On iPad, the presentation depends on the value in the modalPresentationStyle property.

Sets the modalViewController property to the specified view controller. Resizes its view and attaches it to the view hierarchy. The view is animated according to the transition style specified in the modalTransitionStyle property of the controller in the modalViewController parameter.

Availability
Available in iOS 2.0 and later.

Hope this helps you understand that hiding the whole view along with navigation controller is default behaviour for modal view so try putting a seperate navigation bar in modal view to navigate.

You can check it further on this link

http://developer.apple.com/library/ios/#documentation/uikit/reference/UIViewController_Class/Reference/Reference.html

回答6:

AddContactVC *addController =[self.storyboard instantiateViewControllerWithIdentifier:@"AddContactVC"];
UINavigationController *navigationController = [[UINavigationController alloc]initWithRootViewController:addController];
[self presentViewController:navigationController animated:YES completion: nil];

working for me shows navigation bar

回答7:

Emphatic and Devin –

As I started reading through the Apple docs to get familiar with the problem, I noticed that the method you're using, presentModalViewController:animated:, appears to be deprecated in favor of presentViewController:animated:completion:. Perhaps you should try to use that method instead.

For your convenience, take a look for yourself:

presentModalViewController:animated: reference

I'll try to put together a quick test program to see whether what I've said above is actually true. But give it a shot – maybe it'll help!

回答8:

Xcode has a template that does pretty close to what you're doing. from the results, i don't think you should be attempting to perform [self.navigationController presentModalViewController:vc] and [self.navigationController dismissModalViewControllerAnimated:] , but rather simply [self presentModalViewController:] and [self dismissModalViewControllerAnimated:] .

to see how the template does this for yourself, you can use the new project wizard in xcode 4.3 . perhaps it will provide some guidance:

from that choice, choose Next, then give your test project a name, choose "Universal", turn off automatic reference counting, hit next, save where you want it.

now, click on the target and switch the deployment target to 4.3 (or 4.0 if you prefer) for your testing purposes, and switch to your device or the iOS 4.3 simulator .

finally, substitute the following code in applicationDidFinishLaunching:withOptions: in the created AppDelegate.m:

    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    // Override point for customization after application launch.
    if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone) {
        self.mainViewController = [[[MainViewController alloc] initWithNibName:@"MainViewController_iPhone"
                                                                        bundle:nil] autorelease];
    } else {
        self.mainViewController = [[[MainViewController alloc] initWithNibName:@"MainViewController_iPad"
                                                                        bundle:nil] autorelease];
    }
    UINavigationController* navigationController
      = [[UINavigationController alloc] initWithRootViewController:self.mainViewController];
    self.window.rootViewController = navigationController;
    [self.window makeKeyAndVisible];
    return YES;

now, when i run this, it doesn't hide the navigationBar. and in the created MainViewController.m from the template, you'll see how it presents the modal view controller and dismisses it from the controller itself and not from the navigation controller. for good measure, to make the template code more like your own, go into MainViewController.m and delete the line that sets the modal view controller transition style ...

(of course, in iOS 5, with storyboards, the same thing can all be accomplished with modal segues ... which is how i've done this for apps that i'm not supporting for pre-5.0 that present a modalViewController in this fashion.)

回答9:

One of the best solution it to use this Category MaryPopin https://github.com/Backelite/MaryPopin