Iphone: Problem with moving back and forth between two UIViewController - iphone

Let me first describe the context of the problem. I have 2 UIViewController call AdminViewController and ButtonReorderViewController. AdminViewController contain 1 button. ButtonReorderViewController contains 1 button and 1 picture. Button in AdminViewController tie to an event call goToReorderButton. The content of goToReorderButton are below:
ButtonReorderViewController *buttonReorder = [[ButtonReorderViewController alloc] initWithNibName:#"ButtonReorderViewController" bundle:[NSBundle mainBundle]];
UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:buttonReorder]; //Add a Navigation Controller to the root view
[navController setNavigationBarHidden:TRUE];
buttonReorder = (ButtonReorderViewController *) navController;
[[buttonReorder view] setFrame:CGRectMake(0, -20, 320, 470)];
[self.view addSubview:buttonReorder.view];
I use UINavigationController to allow me to swipe left and right.So I am in AdminViewController, and I click on goToReorderButton, it load ButtonReorderViewController. I am able to swipe left and right (awesome !!!) So I click the button in ButtonReorderViewController call goToAdmin, simply to go back to the AdminViewController
-(void) goToAdmin{
[self.view removeFromSuperview];
}
However, as soon as I go back to AdminViewController, I cant click anything at all. The program does not seg fault, it just that I cant click the button at all. if I remove the line buttonReorder = (ButtonReorderViewController *) navController; inside goToReorderButton, then everything work fine. Any idea how to fix this?

I'm not sure that I follow you, but I think that you should use the UINavigationController methods to navigate between the view controllers:
The admin view controller should be the root view controller of the navigation controller and then you may push and pop the reorder view controller.
In app delegate (applicationDidFinishLaunching: method):
// TODO: Instantiate the adminController
UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:adminController];
[window addSubview:navController.view];
In AdminViewController (button touch up inside event handler method):
// TODO: Instantiate the buttonReorder
[self.navigationController pushViewController:buttonReorder animated:YES];
In ButtonReorderViewController (back button touch up inside event handler method):
[self.navigationController popViewControllerAnimated:YES];
Of course, you have to instantiate the view controllers before using them...
Cheers,
Michael.

Sounds like the app crashed on that line you pointed out. Does the debug console output anything when it crashes?
Looks like the line buttonReorder = (ButtonReorderViewController *) navController; is failing on the cast. Are you sure ButtonReorderViewController extends UINavigationController? If not, then you can't cast it like that.

I am not sure but i think you can use PusViewController method of NavigationController to do your job.

Related

How can I hide a button in a different view controller?

I am using this code to hide a button in a different view controller, but the button does not get hidden when the button is pressed to hide the button in the other view controller.
This is the code I am using to hide the button in the other view controller:
[self dismissModalViewControllerAnimated:YES];
NSLog(#"Exited");
ViewController *vc = [[ViewController alloc] initWithNibName:#"ViewController" bundle:nil];
[vc.mainbutton1 setHidden:YES];
Why is this not working?
Thanks!
take a BOOL variable in ViewController controller and make the property and synthesize also.
and do this.
ViewController *vc = [[ViewController alloc] initWithNibName:#"ViewController" bundle:nil];
vc.check = YES;
in the view controller viewdidload
write this
if(self.check)
[mainbutton1 set hidden:YES];
The other answers should work unless...
Judging by your code I am going to guess that you are trying to hide a button on the viewController that presented the modal view?
If this is correct then what you are doing will not work as you are creating a new instance of ViewController which is not the already existing viewController you want to use.
Although the docs say that it is fine to call [self dismissModalViewControllerAnimated:YES]; from the presented modal view I tend to set up a delegate to handle the dismissal like in Apple's utitliy app template.
The reason this isn't working is because even though you have alloc'd and init'd the ViewController properly, the actual elements of that vc ViewController (including mainbutton1) have not been loaded yet.
Hitman has the right idea (and I'm voting his idea up).
Either put in a BOOL property for setting mainButton1 to hidden when the view appears, or call your [mainButton1 setHidden: YES] right after you explicitly display the view (via animation or adding subviews or whatever).
From your question it sounds like you want to hide the button in an existing view controller, whereas in your code you are creating a new one
ViewController *vc = [[ViewController alloc] initWithNibName:#"ViewController" bundle:nil];
[vc.mainbutton1 setHidden:YES];
Either the view controller which you observe is not the one you expect or the mainbutton1 outlet is not connected properly. You can check if the memory controller is the one you expect by logging its memory address.
NSLog(#"Hid button for view controller %p", vc);
And doing the same in the viewDidAppear callback of ViewController
NSLog(#"In viewDidAppear for view controller %p", self);
It seems you want a certain button to be hidden if something has been happening somewhere else.
You COULD, somewhat as a hack (but I don't mind that very much) control this with a variable on your AppDelegate for instance.
When the "something" is happening "somewhere else", do this:
MyAppDelegate *appDelegate = [[(MyAppDelegate *)UIApplication sharedApplication] delegate];
appDelegate.shouldHideThatOtherButtonLater = YES;
Then, when you create your new ViewController later on you could use this value to determine if your button should be visible or not like this:
ViewController *vc = [[ViewController alloc] initWithNibName:#"ViewController" bundle:nil];
MyAppDelegate *appDelegate = [[(MyAppDelegate *)UIApplication sharedApplication] delegate];
[vc.mainbutton1 setHidden: appDelegate.shouldHideThatOtherButtonLater ];
You will in this case have to prepare your AppDelegate for this by creating and synthesizing that shouldHideThatOtherButtonLater-property.

What is the proper way to display a new view from a view and then returning to it in iphone

I have a simple app that have 3 views, HomeView, MenuView and GameView.
In the HomeView I have 2 buttons (Menu and Start Game). When the menu button is clicked, I open the MenuView using the following code:
- (IBAction)displayMenu:(id)sender{
MenuView *mv = [[MenuView alloc] init];
[self.view addSubView:[mv view];
[mv release];
}
In the MenuView, I have a button that will allow the user to return to the HomeView. When this button is clicked, I use the following code to return to the HomeView
- (IBAction)returnToHome:(id)sender{
HomeView* hv = [[HomeView alloc] init];
[self.view addSubView:[hv view];
[hv release];
}
The above code is working but is this the correct way of doing it? I was under the impression that when I call the addSubView, the view will be retain so If keep going back and forth between HomeView and MenuView, will i have multiple instance of HomeView and MenuView retained since I keep calling addSubView from each of the view?
Thank you.
You could use the UINavigationController, which will allow you to push UIViewControllers on to the stack.
Using the UINavigationController you will get an nice naviagtionbar in at the top of you screen and the back button.
You can find a nice example here:http://developer.apple.com/library/ios/#documentation/uikit/reference/UINavigationController_Class/Reference/Reference.html
I found this way the most useful and convenient. When calling the new view use this:
HomeView* hv = [[HomeView alloc] init];
(here you can add a uninavigation controller)
[self presentModalViewController:hv animated:YES];
Then to dismiss this view and go back use this:
[self dismissModalViewControllerAnimated:YES];
#atbebtg:
There is a way to do that, infact there are several, since there not really is a "right way" to do it.
For me this works well:
[[self navigationController] setNavigationBarHidden:YES animated:NO];
This will hide the Navigation Bar, so the user can't go back to the last screen.
The other thing you could do is to create your own subclass of UIViewController and not support the button event, like this:
- (IBAction)done:(id)sender
{
//inform the user, that going back is not possible, for example with UIAlertView
//[self.delegate infoViewDidFinish:self];
}
However, this solution seems a bit odd, because the user expects a existing button to work.
Still, this would work.
Others have given answers that present modal view controllers or build a navigation stack. In most cases I would use one of these approaches. Yet, the simplest way to fix the code in the question is to just remove the menu view from the super view. Something like this:
- (IBAction)returnToHome:(id)sender{
[self.view removeFromSuperview];
}

viewDidDisapper won't call

I have uinavigation controller with a view controller named VC1,now i have a button in VC1 that when i click on him i go to view controller VC2,this is how i bring VC2 to screen :
VC2 *tmp = [[VC2 alloc]init];
[[self navigationController] pushViewController:tmp animated:YES];
[tmp release];
now when i click in VC2 on the back button of the navigation to return to VC1 its work but i put in VC2 viewDidDisappear and viewWillDisappear methods,and when i click on the back button this function won't called, any one have any idea?
You may call the view[..] methods manually from the UINavigationControllerDelegate callbacks, however the easiest way to ensure that the methods are called by the super implementation of the UINavigationController is just to call them manually once when the UINavigationController is allocated.
See my answer here: iPhone viewWillAppear not firing
So immediately after you have called navController = [[UINavigationController alloc] init.., make sure to call
[navController viewWillAppear:NO];
[navController viewDidAppear:NO];
[navController viewWillDisappear:NO];
[navController viewDidDisappear:NO];
This should ensure events are correctly forwarded to each view controller in the future.
If you want to call the viewWillDisappear/viewDidDisappear methods, your view controller has to do that manually before popping itself off the nav stack. Have a look at this
,you might get an idea how to do it.

presentModalViewController NOT animating when showing a TTMessageController

I have a subclass of TTMessageController that shows ... BUT it is not animated even though it should be. The code that displays the modal view looks like this (where PostToWebMessageController is the subclass of TTMessageController:
if (self.toWebMsgController == nil) {
self.toWebMsgController = [[PostToWebMessageController alloc] init];
}
UINavigationController *navController = [[UINavigationController alloc] init];
[navController pushViewController:self.toWebMsgController animated:NO];
[self presentModalViewController:navController animated:YES];
What happens though is this: The screen goes black ... the keyboard scrolls up into view ... and THEN the TTMessageController view shows up (not animated). When I dismiss the view via a Cancel button the screen goes black and then just disappears (no animation again).
Any ideas why this is happening? I've this with a number of other TT* controllers and I can't get one to animate right with showing modally.
Thanks
UPDATE:
This is happening in EVERY UIViewController that I try to present modally. Screen goes black, keyboard animates upwards and then view displays. Any ideas why this might be happening???
A day to figure this out ... hopefully someone will benefit from my pains!
Here is what is happening:
The UIViewController calling presentModalViewController is itself nested inside a UIScrollView that is contained in ANOTHER UIViewController. Apparently, cocoa touch doesn't much like this. Anyhow, to rectify the problem I did the following:
Add a property of type UIViewController to the UIViewController that will present a modal view controller (e.g. #property (nonatomic, retain) UIViewController *owningController;)
Set that property = to the topmost UIViewController (the one that contains the UIScrollView in this case)
In the UIViewController that shows the modal view ... change this
[self presentModalViewController:controller animated:YES];
to this ...
[owningController presentModalViewController:controller animated:YES];
I'm not sure why you are using a UINavigationController. If it is because you would like your toWebMsgController controller to have a nav bar when it loads in the modal view, try the following alterations to your code:
if (self.toWebMsgController == nil) {
self.toWebMsgController = [[PostToWebMessageController alloc] init];
}
UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:toWebMsgController];
//[navController pushViewController:self.toWebMsgController animated:NO];
[self presentModalViewController:navController animated:YES];
If you don't require a nav bar in your modal view, you probably don't need a UINavigationController at all.
I had same issue.
Check that you root controller (if you present controller over it) for presentationStyle DOES NOT set to UIModalPresentationCurrentContext

presentmodalviewcontroller navigationcontroller

I am creating a Navigation based iPhone application.
In that I have called a UiViewController using presentModalViewController. After that, the ViewController becomes visible. From that ViewController I need to call another ViewController using the sample presentModalViewController. Is this possible or not?
What do you mean by "call another uiviewcontroller"? (It really helps if you can be more detailed in your question.) If you mean, "slide in another view controller", then:
MyNewViewController *myNewViewController = [[MyNewViewController alloc] initWithNibName:#"MyNewViewController" bundle:nil];
[navigationController pushViewController:myNewViewController animated:YES];
[myNewViewController release];
...where:
MyNewViewController is the new view controller class that you want to slide in (the above code assumes you have an XIB file for the view controller class).
navigationController points to the current navigation controller. You'll have to replace it with something like [self navigationController], depending where you are in the view hierarchy.
U might be using following line to present a view controller.
//assume name of viewController which u want to present is "myViewController"
[self.navigationController presentModalViewController:myViewController animated:YES]
If you want to push an other ViewController or present an other ViewController then u will need to replace above line with following lines.
//[self.navigationController presentModalViewController:myViewController animated:YES];
UINavigationController *navigationController = [[UINavigationController alloc] initWithRootViewController:myViewController];
navigationController.navigationBarHidden = YES; //if u want to show navigation bar then remove this line
[self presentModalViewController:navigationController animated:YES];
After using above code you can present or push other view controllers within presented view controller.
Hope it will solve your problem :)