I have a modal view controller that initiates a process. If I dismiss the modal view controller, then reopen it, it continues from where it left off. What I want is to (upon dismissal) reset the modal view controller, cancel all processing and reset it to it's initial state. Is there a way?
Cheers
Don't save the UIViewController subclass object in an ivar, just alloc] init] a new one every time you want to present one.
sorry if I'll say something obvious, but I spent some of time to figure out how to do this:
Don't save the UIViewController subclass object in an ivar, just alloc] init] a new one every time you want to present one.
In my case I have this code in MasterViewController.h
#property (strong, nonatomic) ContactsDetailViewController *detailViewController;
and this one in MasterViewController.m
#synthesize detailViewController = _detailViewController;
if (!self.detailViewController) {
self.detailViewController = [[ContactsDetailViewController alloc]
initWithNibName:#"ContactsDetailViewController"
bundle:nil];
}
You should delete this code and use next code in place, where you pushing your modal view controller:
ContactsDetailViewController *detailViewController = [[ContactsDetailViewController alloc] initWithNibName:#"ContactsDetailViewController" bundle:nil];
detailViewController.title = #"View Controller"; // for example
[self.navigationController pushViewController:detailViewController animated:YES];
note: I'm using ARC in this project
Hope it will be helpful for someone
IN the viewDidUnload method of the viewController for your modal view, try stopping the task.
Related
I have a problem on how to properly do a certain kind of action.
The image below shows a UIViewController, but the second part of the view is a custom UIView (the one with the profile pic, name and Show View button).
The subclassed UIView is allocated using this code:
profileView = [[GPProfileView alloc] initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, 70)];
profileView.myTripGradientColor = YES;
[self.view addSubview:profileView];
The problem is of course, that the button on the UIView can't show any view, since it's only the UIViewController that can push another ViewController to the window(correct?).
The UIView is used in several places in the app and needs to be added easily and have the same behavior across the application.
This worked great until I added the button, and I'm starting to think I've made this wrong, and there has to be a better way to do it (maybe change the UIView to something else?).
I was thinking I should be able to call:
self.superview
And then somehow get the ViewController so I can push another ViewController into the view hierarchy, but nope.
Any suggestions and a tips on how to do this correctly?
UPDATE:
I have no idea on how to push another UIViewController from the button.
What should I do in this method when pressing the button in the UIView:
- (void) showViewButtonTouched:(UIButton*)sender {
GPProfileSocialFriendsViewController *friendsSettings = [[GPProfileSocialFriendsViewController alloc] init];
}
How do I push GPProfileSocialFriendsViewController?
Your - (void) showViewButtonTouched:(UIButton*)sender method should be in your controller and would probably be better named - (void) showView:(UIButton*)sender or - (void) showProfile:(UIButton*)sender so it clearly denotes what it does (not how you got there).
It's not the view's responsibility to manage transitions from a state to another. If you move your method to your controller, your problem is no more (you can easily access self.navigationController or push directly if you don't have an navigation controller like this:
[self presentViewController:vcThatNeedsToBePushed animated:YES completion:nil];
I think you can create weak reference in GPProfileView on UIViewController. Like this:
#property (weak, nonatomic) UIViewController *rootController;
when you create GPProfileView, assign rootController-property:
profileView = [[GPProfileView alloc] initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, 70)];
profileView.myTripGradientColor = YES;
profileView.rootController = self; // if view created in view controller
[self.view addSubview:profileView];
and in implementation of button selector:
self.rootController push... // or pop
May be this not correct, but you can try
You could let the view controller push the next view controller when the button is pushed. The view controller can add a target/action on the button, so that the action method in the view controller is called on the touch up inside event.
I am very new to iPhone app development.
I am developing one example application for iPhone emulator using Objective-C++ and std CPP.
I have two views in my application, on some events from CPP code i am displaying second view using following code from the first view controller.
// Defined in .h file
secondViewScreenController *mSecondViewScreen;
// .mm file Code gets called based on event from CPP (common interface function between Objective-C++ and CPP code)
mSecondViewScreen = [[secondViewScreenController alloc] initWithNibName:nil bundle:nil];
[self presentModalViewController:mSecondViewScreen animated:YES];
I am able to see second view coming on screen, but problem is that i am unable to end/remove second view controller from first view controller.
How can i remove second view controller from first view controller using second view controller's pointer or using any other method.
To remove second view i have following code in second view controller file, which gets called on button click event of second view.
// In .mm of second view controller.
- (IBAction)onEndBtnClicked:(UIButton *)sender
{
[self dismissModalViewControllerAnimated:NO];
[self.navigationController popViewControllerAnimated:YES];
}
Above code works perfectly, when i click on the seconds view's end button it removes the second view controller from the screen and navigets to first view, how can i use same code to remove second view from the first view controller.
I tied to use NSNotificationCenter to send event from first view to second view to call the function onEndBtnClicked but it is not working.
What is the proper way of doing it?
OSX version: 10.5.8 and Xcode version: 3.1.3
In the secondViewController create a protocol like:
#protocol SecondViewScreenControllerDelegate <NSObject>
- (void)secondViewScreenControllerDidPressCancelButton:(UIViewController *)viewController sender:(id)sender;
// Any other button possibilities
#end
Now you have to add a property in the secondViewController class:
#property (weak, nonatomic) id<SecondViewScreenControllerDelegate> delegate;
You sinthesize it in the secondViewController implementation:
#synthesize delegate = _delegate;
Finally all you have to do is implement the protocol in your firstViewController and set the secondViewController properly prior presenting it:
#interface firstViewController : UIViewController <SecondViewScreenControllerDelegate>
...
#implementation firstViewController
- (void)secondViewScreenControllerDidPressCancelButton:(UIViewController *)viewController sender:(id)sender
{
// Do something with the sender if needed
[viewController dismissViewControllerAnimated:YES completion:NULL];
}
Then when presenting the secondViewController from the first:
UIViewController *sec = [[SecondViewController alloc] init]; // If you don't need any nib don't call the method, use init instead
sec.delegate = self;
[self presentViewController:sec animated:YES completion:NULL];
And ready. Whenever you want to dismiss the secondViewController from the first, just call: (inside the secondViewController implementation)
[self.delegate secondViewScreenControllerDidPressCancelButton:self sender:nil]; // Use nil or any other object to send as a sender
All that happens is that you send a pointer of the secondViewController that you can use from the first. Then you can work with it without problem. No C++ needed. In Cocoa you won't need C++. Almost everything can be done with Objective-C, and it's more dynamic.
If there are only two views in your application then use
- (IBAction)onEndBtnClicked:(UIButton *)sender
{
[self dismissModalViewControllerAnimated:NO];
}
remove line below:
[self.navigationController popViewControllerAnimated:YES];
as it is you are dismissing second view then why you want to remove it from first view.
I have made a very simple Navigation based app (UIViewController). The view has a single button on the Main RootViewController.
Next, I made 2 classes: TabOneViewController, TabTwoViewController. All good. I then created a new Class TabBarViewController. I opened up the NIB file and dropped on a ``UITabBarController onto it. The two tabs it creates in it by default were assigned (respectively) to my TabOne and TabTwo view controllers.
strong text
Then in my TabBarViewController, I made an IBOutlet for a UITabBarController, synthesized it etc etc. I linked it up in Interface builder via the "files owner".
In the RootViewController, I linked the button to my "pushView" method, and in this pushView method, I have the following code:
- (IBAction) pushView {
TabBarViewController *controller = [[TabBarViewController alloc] init];
[self.navigationController pushViewController:controller animated:YES];
[controller release];
}
The end result is it DOES push a view, but I cannot see the tab bar at the bottom, let alone any of the pages I've added to the controller.
What am I doing wrong? Why can't I link it in IB?
I am not 100% sure if that's allowed.. because you already have one tabBarController as rootViewController, and you dropped one more tabBarController as first tab controller, tabs ll overlap, considering amount of real estate you have on your iPhone, it make sense to not allow a tabViewController inside another
First, you need to allocate your view controller with your nib:
TabBarViewController *controller = [[TabBarViewController alloc] initWithNibName:#"YourNibName" bundle:nil];
Secondly, in IB, click the UITabBarController and go to the identity inspector and make sure you select your custom class. That said, unless you are overriding or adding some functionality you probably don't need the custom class at all, simply use a UITabBarController directly:
UITabBarController *controller = [[UITabBarController alloc] initWithNibName:#"YourNibName" bundle:nil];
I am in the appdelegate of my application. How can I add a modal view controller in the "didfinishlaunching" method?
I tried the following but did not work
SomeViewController *vc = [[SomeViewController alloc]init];
[self.tabController.navigationController presentModalViewController:vc animated:NO];
EDIT:
I changed my implementation to the following
self.tabController.selectedViewController
= [self.tabController.viewControllers objectAtIndex:0];
SomeViewController *vc = [[SomeViewController alloc]init];
[self.tabController.selectedViewController presentModalViewController:vc animated:NO];
I checked that the 'selected view controller' is not null... however I am still not able to get the output I needed. Is there anything I am missing?
Assuming tabController and navigationController are not nil, the applicationDidFinishLaunching may be too soon to display the modal view controller.
Make sure you put that code after you make the window key and visible. [self.window makeKeyAndVisible];
If that does not work try listening for the UIWindowDidBecomeKeyNotification for that window
You can try delaying presentation of that modal a few seconds using performSelector:withObject:afterDelay:
I know this question has been asked several times and I did read existing posts on this topic but I still need help.
I have 2 UIViewControllers - parent and child. I display the child UIViewController using the presentModalViewController as below:
ChildController *child =
[[ChildController alloc] initWithNibName:#"ChildView" bundle:nil];
[self presentModalViewController:child animated:YES];
[child release];
The child view has a UIPickerView. When user selects an item from UIPickerView and clicks done, I have to dismiss the modal view and display the selected item on a UITextField in the parent view.
In child's button click delegate, I do the following:
ParentController *parent =
(ParentController *)[self.navigationController parentViewController];
[parent.myTextField setText:selectedText];
[self dismissModalViewControllerAnimated:YES];
Everything works without errors. But I don't know how to load the parent view so that it displays the updated UITextField.
I tried
[parent reloadInputViews];
doesn' work. Please help.
Delegation is the way to go. I know some people that may be looking for an easier solution but trust me I have tried others and nothing works better than delegation. So anyone having the same problem, go read up on delegation and follow it step by step.
In your subviewcontroller.h - declare a protocol and declare delegate mthods in it.
#protocol myDelegate
-(void)clickedButton:(subviewcontroller *)subController;
#end
In your subviewcontroller.h, within #interface:
id<myDelegate> delegate;
#property (nonatomic, assign) id<myDelegate> delegate;
NSString *data;
-(NSString *)getData;
In your subviewcontroller.m, synthesize myDelegate. Add the following code to where you want to notify your parentviewcontroller that the subview is done doing whatever it is supposed to do:
[delegate clickedButton:self];
and then handle getData to return whatever data you want to send to your parentviewcontroller
In your parentviewcontroller.h, import subviewcontroller.h and use it's delegate
#import "subviewcontroller.h"
#interface parentviewcontroller : VUIViewController <myDelegate>
{}
In your parentviewcontroller.m, implement the delegate method
- (void)clickedButton:(subviewcontroller *)subcontroller
{
NSString *myData = [subcontroller getData];
[self dimissModalViewControllerAnimated:YES];
[self reloadInputViews];
}
Don't forget memory management!
If a low-memory warning comes in during your modal view's display, the parent's view will be unloaded. Then parent.myTextField is no longer referring to the right text field until the view is reloaded. You can force a reload of the view just by calling parent.view;
However, a better idea might be to have the parent view have a String property that can be set by the child view. Then, when the parent view reappears, put that data into the text field, inside viewWillAppear: for example. You'd want to have the value set to some default value for when the parent view initially shows up too.
-(void) viewWillAppear:(BOOL) animated doesn't get called for me either, exactly when it's a modal view controller. No idea why. Not incorrectly overridden anywhere in this app, and the same problem occurs on the other 2 apps I'm working on. I really don't think it works.
I've used the delegate approach before, but I think that following approach is pretty good as well.
I work around this by adding a private category to UIViewController, like so:
.h file:
#interface UIViewController(Extras)
// returns true if this view was presented via presentModalViewController:animated:, false otherwise.
#property(readonly) BOOL isModal;
// Just like the regular dismissModalViewController, but actually calls viewWillAppear: on the parent, which hasn't been working for me, ever, for modal dialogs.
- (void)dismissModal: (BOOL) animated;
#end
and .m file:
#implementation UIView(Extras)
-(BOOL) isModal
{
return self == self.parentViewController.modalViewController;
}
- (void)dismissModal: (BOOL) animated
{
[self.parentViewController viewWillAppear: animated];
[self dismissModalViewControllerAnimated: animated];
}
#end
which I can now call like this when I want to dismiss the dialog box:
// If presented as a modal view, dismiss yourself.
if(self.isModal)
[self dismissModal: YES];
and now viewWillAppear is correctly called.
And yes, I'm donating a bonus 'isModal' property, so that the modal view can tell how it was being presented, and dismiss itself appropriately.