I have a view based application. I am trying to load a second custom view controller when the app starts. I have the following code :
- (void)viewDidLoad
{
controller = [NewController alloc];
[self presentModalViewController:controller animated:YES];
[controller release];
[super viewDidLoad];
}
The problem is that the new view controller is not loading and viewDidLoad is not called. I have no xib file for the second view controller.
Can anyone help ?
It won't work in your viewDidLoad or viewWillAppear methods. Use viewDidAppear instead.
You're missing a call to init your view controller...
- (void)viewDidLoad
{
controller = [[NewController alloc] init];
[self presentModalViewController:controller animated:YES];
[controller release];
[super viewDidLoad];
}
Related
I have a root ViewController class, and call the OnlineViewController's View like this:
- (void)eventTap:(UIGestureRecognizer *)gestureRecognizer {
self.evc = [[EventViewController alloc]init];
[self presentViewController:self.evc animated:YES completion:nil];
}
And I tried to Call The ViewController'S View from OnlineViewController, but it's failed :
-(void ) iconAction{
self.vc = [[ViewController alloc]init];
[self presentViewController:self.vc animated:YES completion:nil];
}
How Can I call ViewController's view?
try and dismiss this viewController rather than Presenting a new one
[self dismissViewControllerAnimated:YES completion:nil];
also make sure your iconAction: method is called.
I'm not sure how to do this. So I originally had a ViewController that had one .xib, with one main view. I present it like this:
DogViewController *dvc = [[DogViewController alloc] initWithNibName:#"DogViewController" bundle:nil];
dvc.modalPresentationStyle = UIModalPresentationFormSheet;
dvc.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
[self presentModalViewController:dvc animated:YES];
[dvc release];
So that works fine. However now from a button press in the DogViewController.xib, I want to dismiss the current form sheet, and show another form sheet with some additional questions before proceeding. So I started by adding another view to in my original .xib of DogViewController, then got stuck in the logic of how to dismiss the first one, and show the second one. I'm assuming I need some outlet to the new view in the same .xib, but from there I'm lost. Thanks.
The way to do this would be to set it up with a UINavigationController as Mathiew mentions. However, if you really want to transition between two views on one view controller, you can refer to this sample code from Apple:
http://developer.apple.com/library/ios/#samplecode/ViewTransitions/Introduction/Intro.html
The code uses ImageViews to demonstrate the effect but I don't see why you can't use views instead :)
You can add a view within the other view in front of all of the other objects and just use its hidden property to control whether it's shown or not.
Why don't you use a navigation controller in your modal view, create another xib and do a [self.navigationController pushViewController:secondViewController animated:YES];
If you have a good reason, you can set a second view outlet secondView and use code like
UIView* superview = [self.view superview];
[self.view removeFromSuperView];
[superview addSubview:self.secondView];
Very simple solution is to hold reference to MainViewController and call methods on it that swap between two view controllers.
Like this:
#implementation MainViewController
- (void)showDogViewController {
[self dismissModalViewControllerAnimated:YES];
DogViewController *dvc = [[DogViewController alloc] initWithNibName:#"DogViewController" bundle:nil];
dvc.modalPresentationStyle = UIModalPresentationFormSheet;
dvc.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
dvc.mainViewController = self;
[self presentModalViewController:dvc animated:YES];
[dvc release];
}
- (void)showCatViewController {
[self dismissModalViewControllerAnimated:YES];
CatViewController *cvc = [[CatViewController alloc] initWithNibName:#"CatViewController" bundle:nil];
cvc.modalPresentationStyle = UIModalPresentationFormSheet;
cvc.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
cvc.mainViewController = self;
[self presentModalViewController:cvc animated:YES];
[dvc release];
}
}
#end
#implementation DogViewController
- (void)showCatViewController {
[mainViewController showCatViewController]
}
#end
#implementation CatViewController
- (void)showDogViewController {
[mainViewController showDogViewController]
}
#end
Im presenting and dismissing a Modal View Controller. I use delegation so I dismiss the modalView at the Parent.
- (void)launchDrawingSection{
drawingSectionViewController = [[DrawingSectionViewController alloc] init];
drawingSectionViewController.modalTransitionStyle = UIViewAnimationTransitionFlipFromLeft;
drawingSectionViewController.drawingModalDelegate = self;
[self presentModalViewController:drawingSectionViewController animated:YES];
}
- (void)didDismissDrawingModalView{
NSLog(#"didDismissDrawingModalView");
[drawingSectionViewController release];
[self dismissModalViewControllerAnimated:YES];
}
The app crashes after the dealloc method in the ModalView gets called.
Am I doing something wrong with the way I present and dismiss a Modal View Controller? Any idea?
Don't release before dismiss.
- (void)launchDrawingSection{
drawingSectionViewController = [[DrawingSectionViewController alloc] init];
drawingSectionViewController.modalTransitionStyle = UIViewAnimationTransitionFlipFromLeft;
drawingSectionViewController.drawingModalDelegate = self;
[self presentModalViewController:drawingSectionViewController animated:YES];
[drawingSectionViewController release];
}
- (void)didDismissDrawingModalView{
NSLog(#"didDismissDrawingModalView");
[self dismissModalViewControllerAnimated:YES];
}
Your fundamentals of Modal View Controller is not clear.
If you are using delegate protocols only to inform the drawing sections's parent control to dismiss the drawing section controller, then this is something useless. Because, the following thing does your job without use of delegates.
// Present drawing section.
- (void)launchDrawingSection{
drawingSectionViewController = [[DrawingSectionViewController alloc] init];
drawingSectionViewController.modalTransitionStyle = UIViewAnimationTransitionFlipFromLeft;
drawingSectionViewController.drawingModalDelegate = self;
[self presentModalViewController:drawingSectionViewController animated:YES];
[drawingSectionViewController release];
}
// (Put this in Drawing Section View Controller). This function dismisses drawing section.
- (void)dismissActionEvent{
// Drawing section view controller is asking its parent to dismiss it.
[self.parentViewController dismissModalViewControllerAnimated:YES];
}
To understand clearly how presenting and dismissing modal view controller's work, refer to my answer here
I have the following code where I display a view controller within a navigation controller.
Just for the test I display it for 3 seconds and then dismiss it.
What is happening is that it disappearing - and then reappearing after a second or so.
What am I doign wrong?
- (void) test
{
[myNavCtrl dismissModalViewControllerAnimated:YES];
}
- (void) viewDidAppear:(BOOL)animated
{
MyViewController *ctrl = [[MyViewController alloc] init];
[ctrl setDelegate:self];
myNavCtrl = [[UINavigationController alloc] initWithRootViewController:ctrl];
[myNavCtrl setModalTransitionStyle:UIModalTransitionStyleCrossDissolve];
[self presentModalViewController:myNavCtrl animated:NO];
[ctrl release];
[myNavCtrl release];
[self performSelector:#selector(test) withObject:nil afterDelay:3];
}
The viewWillAppear method is called every time the controller's view appears so you've created a loop. The view appears, it calls the modal view which covers the calling view. When the modal view disappears, the calling view controller's viewWillAppear gets called again. Lather, rinse, repeat.
here's my code:
ViewController *vc = [[ViewController alloc] initWithNibName:#"TableView" bundle:nil];
[self.navigationController presentModalViewController:vc animated:YES];
//[self setView:[vc view]];
If I call it, nothing happens. However, if I change it to:
ViewController *vc = [[ViewController alloc] initWithNibName:#"TableView" bundle:nil];
//[self.navigationController presentModalViewController:vc animated:YES];
[self setView:[vc view]];
The view appears just fine (without the transition, of course).
What am I doing wrong? Is there anything special you have to take care of when initializing the view controller? I tried to copy as much as possible from Apple's examples, but I can't get this to work...
Thanks for any input!
-- Ry
You can only present modal view controllers from controllers that have already been shown onscreen (usually through a UINavigationController or UITabBarController). Try creating a UINavigationController, pushing a viewController to it, and then presenting your modal controller. There's a starter project in Xcode that shows how to create a UINavigationController-based flow if you're unfamiliar with it.
One other thing to note: if you haven't pushed the view controller onto a UINavigationController, the .navigationController property will be nil, and messaging it will have no effect.
I encountered the same problem while attempting to show a modal view over another modal view. Ben's answer is correct, and can be implemented like so:
#interface FirstView: UIViewController {
UIViewController *firstView;
}
- (IBAction)showOptionsView:(id)sender;
#end
In the main view class:
- (void)viewDidLoad {
[super viewDidLoad];
firstView = [[UIViewController alloc]init];
[firstView setView:self.view];
[firstView setModalTransitionStyle:UIModalTransitionStyleCoverVertical];
}
- (IBAction)showOptionsView:(id)sender {
OptionsView *optView = [[OptionsView alloc]initWithNibName:#"OptionsView" bundle:nil];
if(firstView != nil) {
[firstView presentModalViewController:optView animated:YES];
[optView release];
}