dismissModalViewControllerAnimated also dismisses the view controller that calls it - iphone

I've got a view controller which is presented as a modal view controller on startup by the delegate. This view controller has an option to select an image using a UIImagePickerController which is presented using presentModalViewControllerAnimated. After this I implement the
imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
method and call dismissModalViewControllerAnimatedon it, but this dismisses both of the modal view controllers. I can't seem to keep the first view controller open when the second is closed.

Who are you calling dismissModalViewControllerAnimated on? You want to call it on the view controller that presented the modal view you want to dismiss.

Related

Dismissing modalviewcontroller issue

What is the a way for the modal controller to talk to the presenting controller.
In my case i m presenting modalviewcontroller without using delegate. But want to dismiss modalviewcontroller using delegate protocol.
SO can i dismiss modalviewcontroller using delegate protocol where i m presenting modalviewcontroller without using delegate.
The modal controller can dismiss itself. Within the modal view controller, use [self dismissModalViewController animated:YES] (or NO if you don't want to animate it). If you include that line of code in the modal controller, then you should be okay!
dismissModalViewControllerAnimated:
The parent view controller is responsible for dismissing the modal view controller it presented using the presentModalViewController:animated: method. If you call this method on the modal view controller itself, however, the modal view controller automatically forwards the message to its parent view controller.
via iOS Documentation
You can also access the parent view controller through [self.parentViewController ...]

Change modal UIImagePickerController parent view

I'm trying to build an app that features a button on the first view, when you tap the button it presents the UIImagePickerController modal view. What I would ideally like is once you have taken you photo, when the modal view is dismissed, the original view which presented the image picker changes.
For example, the process would be VIEW 1 -- (tap button) --> MODAL IMAGE PICKER -- (close modal view) --> VIEW 2.
So far I've got the app loading the UIImagePickerController and once you are complete, within the didFinishPickingMediaWithInfo delegate method, it sets a BOOL value to YES and then within the ViewDidAppear of my original view (VIEW 1) it then presents a new modal with the next view.
The problem with this is that there is a delay between the closing the modal view and the next view (VIEW 2) appearing.
Does anyone know if the above is possible? If not, I might have to resort to displaying a spinner and saying "Processing image" between the image picker closing and the second view appearing.
You can use a navigation controller to solve this problem.
Create a navigation controller and push your first controller into it. Later from your first controller, present the picker modally. Pretty much the same until now except that we have added a navigation controller. This is what I did to get your desired result.
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
NewController *controller = [[NewController alloc] initWithNibName:nil bundle:nil];
[self.navigationController pushViewController:controller animated:YES];
[self dismissModalViewControllerAnimated:YES];
[controller release];
}
Hope this helps.

Canceling a modal view & app crashes

I have a confusion on canceling the modal views:
Case 1: I have a navigation view controller and I am presenting a modal view controller from this navigation view controller. Now, when I am to cancel this modal view from where should I call the dismissModalView method -- navigation view controller or the modal view controller?
Case 2: I have a modal view controller and I am presenting another modal view controller from first modal view controller. Now, when I am to cancel second modal view from where should I call the dismissModalView method -- frist modal view controller or the second modal view controller?
Will canceling it from a wrong place cause a app crash also?
An advisable way to handle modal view controllers is to us notifications to inform the class that presented it to release it. Generally, you use code similar to this to show a modal view.
SomeClass *yourViewController = [[SomeClass alloc] initWithNibName:#"SomeClass" bundle:nil];
[self presentModalViewController: yourViewController animated: YES];
[yourViewController release];
With the above code, your modal view should end up with a retain count of 1. When you dismiss it, the parent view will release it and it will be purged from memory. Your "close" button in your modal view should execute code that looks like this:
- (void)dismissSelf{
[[NSNotificationCenter defaultCenter] postNotifivationName:#"I'm done" object:self];
}
Back in your parent viewcontroller, ou should listen for this notification and then dismiss the modal view when the notification is posted.
That said, to answer your questions:
A modal view controller never dismisses itself. Post a notification and then let the navigation controller handle it.
You can't dismiss the first modal view until the second one has been dismissed. If you do, you will get a EXC_BAD_ACCESS error. Think of the second modal view as "inside" the first one. If the first is dismissed, the second one will be dragged away with it, but it hasn't been dismissed.
you should dismiss the modal view
controller.
you should dismiss it from the
second modal view controller.
the app crashes because when you trying to dismiss the modal view controller , the scope of corresponding view controller is lost, may be u released the view controller before dismissing
You always dismiss the modal view from the controller, where you presented it (with dismissModalViewControllerAnimated). So:
in the navigation controller
in the first modal view controller

UIViewController -dealloc Being Called After Dismissing Modal View Controller

I have a view in my app that displays a UITableView. This view is created in a nib file and has a custom view controller. The UIViewController subclass for this view acts as the Datasource and Delegate for the UITableView.
My UITableView displays several rows based on my data. Then, the last row displays different text: "Add another...". If the last row is selected, I present a modal view controller (to allow the user to add more data). When I dismiss the modal view controller, I again see the original view (as expected) and all appears to be well. However, when I try to interact with this view, the app crashes.
From placing several NSLog() statements through the UIViewController (for the UITableView), I have determined that the -dealloc method is being called just after the modal view is dismissed. This explains the crash when I try to do something with that view. However, I have no idea why -dealloc is being called on this view controller.
To dismiss the modal view controller, I have:
[self dismissModalViewController:YES];
As the code in an IBAction method in the modal view controller's UIViewController. This action is tied to a cancel button in the corresponding nib file.
In addition, my understanding from the View Controller Programming Guide is that it's OK to dismiss the modal controller from within itself, but it's more robust to use delegates. I was initially using a delegate, but took the delegate out to simplify debugging. I just put the delegate back in to double-check, and the same behavior occurs when using delegates. The modal controller's action method calls is implemented as:
[[self delegate] myModalViewController:self didAddObject:obj];
The delegate implementation in the parent view controller is:
[self dismissModalViewController:YES]
If anyone has seen this before or has any suggestions of what could be happening or how to debug this, I would greatly appreciate it.
If -dealloc is being called, something is releasing the view controller. Try implementing -release in your view controller:
-(void)release {
NSLog(#"view controller released");
[super release];
}
so that you can use the debugger to inspect the call stack when this unexpected release message happens.
Its dangerous to call dismissModalViewController from the modal view controller itself (message will be forwarded to parent view controller), if you have not retained it elsewhere. Normally, the parent view controller is responsible for dismissing the modal view controller it presented.

modal view not showing inside didfinishpickingimage

I have a viewcontroller, and I would like to display a modal view controller with :
presentModalViewController when a user finished picking an image.
The modal view controller is working fine when I call it from a button in my main view.
But when I call it from didfinishpickingimage callback nothing happens.
Thanks.
Try
[picker dismissModalViewControllerAnimated:NO];
before
[self presentModalViewController:MY_VIEW_CONTROLLER animated:YES];
Note the animated variable
I had a similar issue. I decided to push the view controller I wanted to display after selecting an image onto my navigation controller instead of trying to present a modal view controller. It has the same effect as presenting a modal.
So I just did:
[self.navigationController pushViewController:MY_VIEW_CONTROLLER animated:YES];