removing Views from SubView - iphone

I have a App that uses the In App feature.
-(void) completeTransaction: (skPaymenttransaction *)transaction{
}
When the above method gets called i want to remove all subviews and go back to my main menu window (the first view in my App).
Can anyone suggest to cleanest and best way to do this?
Cheers
EDIT:
Just to make things clear
Im not sure if this makes a difference but i have my main menu screen, then iam doing the following with an enter button.
UIViewController *controller = [[UIViewController alloc] initWithNibName:#"NibFile" bundle:nil];
controller.delegate = self;
controller.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
[self presentModalViewController:controller animated:YES];
[controller release];
Then i have a main screen with a button then when a user taps it, it then presents them with another modal view controller as above. On this view is a button that says BUY on it. They use clicks this and then the StoreKit does it business and once the payment is complete i want to get rid of the two modal controllers above and be left with the main menu screen.
Any Ideas.. ive tried as above
EDIT 2:
#Jordan Thanks,
But not sure if im doing this correctly. I understand the above code.
But when i start my app my app delegate loads a viewcontroller which is my main menu. Then i have a button that takes me to another view and on there is my features if the user clicks a feature that is not unlocked then it displays another view controller with the store on.
So with this in mind how do i get back to my main menu.
I have tried the following:
NSArray *subviews = [myAppdelegate.viewcontroller.view subviews];
for (int i=0; i<[subviews count]; i++)
{
[[subviews objectAtIndex:i] removeFromSuperview];
}
but i get and error along the lines of:
expected ':' before '.' ?

This should work.
// view is equal to your main view
NSArray *subviews = [view subviews];
for (int i=0; i<[subviews count]; i++)
{
[[subviews objectAtIndex:i] removeFromSuperview];
}

If you're talking about UIViewControllers and not subViews (they are different),then you can use:
[self.navigationController popToRootViewControllerAnimated:YES];
You're either adding UIViews to a UIViewController, in which case use my code above, or You're pushingViews (e.g. pushViewController) on top of a UIViewController, in which case use the code here.

We have to get the views to be removed in an array so that we can remove everything by means of enumeration
NSArray *ChildViews = [ParentView subviews];
for (UIView *childView in ChildViews) {
[childView removeFromSuperview];
}

Related

Navigating between several views in iphone

Hi I have three views and I would like to achieve something that doesn't work. I have a main view if user presses a certain button the code checks if he is logged or not:
if yes he is sent directly to view B if not first he goes to login view.
After successfull login I have this code to go to view b:
incidencias =[[MisIncidencias alloc]
initWithNibName:#"MisIncidencias"
bundle:nil];
[self.view addSubview:incidencias.view];
the thing is I would like to get rid of the login view because it shows there underneath plus if user clicks back it goes back to login but if I add:
[self.view removeFromSuperview];
either before or after [self.view addSubview:incidencias.view], I just get redirected to the main view;
I don't know if I explained myself clearly but for example in Android you can just call finish and then call next activity and the login activity disappears but here in iphone I don't know what to do.
I have found another solution is to add both views one after another but it doesn't really work well:
incidencias=[[MisIncidencias alloc]
initWithNibName:#"MisIncidencias"
bundle:nil
];
[self.view addSubview:incidencias.view];
login=[[LoginViewController alloc]
initWithNibName:#"LoginViewController"
bundle:nil];
[self.view addSubview:login.view];
it doesn't work well because incidencias starts and doesn't wait for login to finish.
thanks
EDIT: thanks to beOn I have modified my code adding the protocol:
LoginViewControllerDelegate
and this method inside viewController:
- (void)loginSucceededFromController:(LoginViewController*)viewController {
[viewController.view removeFromSuperview];
incidencias =[[MisIncidencias alloc]
initWithNibName:#"MisIncidencias"
bundle:nil];
[self.view addSubview:incidencias.view];
}
in LoginViewController I have
- (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex: (NSInteger)buttonIndex{
if(self.delegate)
[self.delegate loginSucceededFromController:self]
}
it gets an error:
Semantic Issue: Property 'delegate' not found on object of type 'LoginViewController *'
if login is successful the user sees an alert and once he clicks on ok is when the method above gets called.
what else should I add? I am beginning with iphone and I don't understand very well what is delegate (I come from java)
Ah, okay, this ain't so bad. Here's the first solution that comes to mind:
Step 1. Create a delegate protocol for your login view.
#protocol LoginViewControllerDelegate <NSObject>
#required
- (void)loginSucceededFromController:(LoginViewController*)viewController;
#end
Step 2. Implement the protocol in your main view controller
- (void)loginSucceededFromController:(LoginViewController*)viewController {
// TODO: we'll put something here in a second
}
Step 3. Call the delegate method from your login view on successful login
if (loginSuccess && self.delegate) {
[self.delegate loginSucceededFromController:self]
}
Step 4. Dismiss the login view and present the new view from the main view controller using the code you already have:
- (void)loginSucceededFromController:(LoginViewController*)viewController {
[viewController.view removeFromSuperview];
incidencias =[[MisIncidencias alloc]
initWithNibName:#"MisIncidencias"
bundle:nil];
[self.view addSubview:incidencias.view];
}
Hopefully that clears things up some. The reason you were having trouble is that you were either adding a subview to a view, then immediately removing the view, or removing the view, then adding a subview to it. In the code above, you call the view's controller's delegate, and the delegate, which happens to own the superview of the view, first removes the view, then adds a newView (for lack of a better term) to the superview. Since the superview was never removed, it's able to show your newView.
You have to take BOOL which one can access through out application like global
like extern BOOL login; now once you login set to YES. now check when
if(login == YES){
incidencias=[[MisIncidencias alloc]
initWithNibName:#"MisIncidencias"
bundle:nil
];
[self.view addSubview:incidencias.view];
}
else{
login=[[LoginViewController alloc]
initWithNibName:#"LoginViewController"
bundle:nil];
[self.view addSubview:login.view];
}
If you want something working right away, and you are using uinavigationcontroller... then u can possibly make use of
- (void)setViewControllers:(NSArray *)viewControllers animated:(BOOL)animated
just get a mutable copy of the self.navigationController.viewcontrollers array, pop out the last element, which will be the login screen and push in the new screen where you are planning to move screen b.. and pass the array to this function.. and you are now safe!

efficient way of making a multiview app?

The app I'm making utilizes multiple views. such as a disclaimer view, a view to display answer so on and so forth.Up until now this is the code that I've been using to switch from one view to another
-(IBAction)swichtogain:(id)sender{
gainview *second = [[gainview alloc]initWithNibName:nil bundle:nil];
[self presentModalViewController:second animated:YES];
[second release];
}
I found this method in a tutorial, I was wondering, is this the best way to do it ? I use the same code to switch back n forth from one view to another for eg.
-(IBAction)swichtoview1:(id)sender{
view1 *view = [[gainview alloc]initWithNibName:nil bundle:nil];
[self presentModalViewController:view animated:YES];
[view release];
}
and when in view1 if the user hits the back button the following code gets executed
-(IBAction)swichtomainview:(id)sender{
mainview *view = [[gainview alloc]initWithNibName:nil bundle:nil];
[self presentModalViewController:view animated:YES];
[view release];
}
I haven't edited anything in the appdelegate files and this is a view based app. Does this method cause it to use more memory ? During the activity monitor test using the instruments , I noticed the memory usage gets higher every time I go from the main menu to another view and back to the main menu !. Is there a better way than this ?. Also one of the view is a calculator so when the user hits the calculate button it switches to the next view while changing the textfield to the answer, below is the code for that !
-(IBAction)calculate{
MyClass *setnum = [[MyClass alloc]init];
setnum.grade_num = grade;
setnum.stage_num = stage;
setnum.ex_lym = ex_ly;
setnum.pos_lym = pos_ly;
setnum.er_num = er;
setnum.noderatio = pos_ly/ex_ly;
if(text1.text.length <=0 ||text2.text.length <=0||text3.text.length<=0||text4.text.length<=0||text5.text.length <=0){
UIActionSheet *action = [[UIActionSheet alloc]initWithTitle:#"Incomplete Values" delegate:self cancelButtonTitle:#"Ok" destructiveButtonTitle:nil otherButtonTitles:nil];
[action showInView:self.view];
[action release];
}else{
answer *ans =[[answer alloc]initWithNibName:nil bundle:nil];
[self presentModalViewController:ans animated:YES];
float i = calc_gain(setnum.grade_num, setnum.noderatio, setnum.stage_num, setnum.er_num);
NSString *result = [NSString stringWithFormat:#"%f",i];
ans.answer1.text = result;
ans.bar.hidden = NO;
[ans release];
}
[setnum release];
}
You should consider using one of the provided container view controllers (UITabBarController, UINavigationBarController or UISplitViewController on the iPad and so on).
The way you use presentModalViewController is most likely the wrong way. For one, calling presentModalViewController will retain your views. Keeping allocating new controllers and displaying their views via presentModalView is therefore increasing your memory footprint with each navigation step.
In general, a viewcontroller which shows another modal viewcontroller is also responsible for dismissing it again. The way to dismiss a modal view controller is therefore to let the presented controller inform its parent through delegation and ask the parent to dismiss (often on tapping a 'done' button).
I'm not even sure whether stacking modalViewControllers is a supported scenario, but at least didn't find anything stated otherwise in the documentation.
Asked here yesterday:
Switching views for iphone application - is this the right way?
I think another good way to go about this is to do this and add a univanigationcontroller:
[self.navigationController pushViewController:second animated:YES];

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];
}

Sending data from my detail view back to my UITableView

First of all, thank God for Stack Overflow. I am new at Objective-C/Cocoa/iPhone development, and this site is an amazing aid.
I have a window, that has a tab bar, that has a navigation controller, that loads a UITableViewController. Clicking an "Add" button on the navigation bar (created programatically), pushes a UITableViewController like so:
InvoiceAddViewController *addController = [[InvoiceAddViewController alloc] initWithNibName:#"InvoiceAddViewController" bundle:[NSBundle mainBundle]];
[self.navigationController pushViewController:addController animated:YES];
This table view controller pushes it's own detail view:
UITableViewCell *targetCell = [self.tableView cellForRowAtIndexPath:indexPath];
GenericTextFieldDetailViewController *dvController = [[GenericTextFieldDetailViewController alloc] initWithNibName:#"GenericTextFieldDetailViewController" bundle:[NSBundle mainBundle]];
dvController.fieldName = targetCell.textLabel.text;
dvController.fieldValue = targetCell.detailTextLabel.text;
[self.navigationController pushViewController:dvController animated:YES];
[dvController release];
The concept being, you click on a cell in the table view controller such as "Notes". This pushes "GenericTextFieldDetailViewController" with the name of the "field" you clicked, and the value (if one already exists). This allows me to reuse my detail view rather than creating one ad nauseum for every field.
In order to push data back, I created a method on the "Add" UITableViewController:
- (void) updateField:(NSString*) fieldName value:(NSString*) fieldValue
{
UITableViewCell *targetCell;
if([fieldName isEqualToString:#"Invoice ID"])
{
NSUInteger indexArr[] = {1,1};
targetCell = [[self tableView] cellForRowAtIndexPath:[NSIndexPath indexPathWithIndexes:indexArr length:2]];
targetCell.detailTextLabel.text = fieldValue;
}
else if([fieldName isEqualToString:#"P.O. Number"])
{
NSUInteger indexArr[] = {1,2};
targetCell = [[self tableView] cellForRowAtIndexPath:[NSIndexPath indexPathWithIndexes:indexArr length:2]];
targetCell.detailTextLabel.text = fieldValue;
}
else if([fieldName isEqualToString:#"Add Note"])
{
NSUInteger indexArr[] = {3,0};
targetCell = [[self tableView] cellForRowAtIndexPath:[NSIndexPath indexPathWithIndexes:indexArr length:2]];
targetCell.detailTextLabel.text = fieldValue;
}
}
This method is designed to receive the data I push with this method in "Generic":
- (IBAction)saveField:(id)sender
{
self.fieldValue = theTextField.text;
InvoiceAddViewController *parentController = (InvoiceAddViewController*)self.view.superview;
[parentController updateField:self.fieldName value:self.fieldValue];
}
Which brings us to the problem:
When the save method fires off, it throws an invalid selector error because self.view.superview is not the UITableView that pushed the "Generic" detail view.
I have tried the following combinations (from GDB):
(gdb) po [[self view] superview]
<UIViewControllerWrapperView: 0x4b6d4d0; frame = (0 64; 320 367); autoresize = W+H; layer = <CALayer: 0x4b6c090>>
(gdb) po [[self navigationController] parentViewController]
<UITabBarController: 0x4d2fa90>
(gdb) po [self parentViewController]
<UINavigationController: 0x4d2fdc0>
I feel like I'm landing all around the UITableView I want to invoke, but can't find it.
What am I doing wrong?
refrains from pulling more hair out
The problem is that you are confusing the view hierarchy for the navigation stack. Your detail view controller wants to send a message to the controller that pushed it on the stack, which is the second to last object in the navigation controller's viewControllers array.
Try changing your saveField: method to:
- (IBAction)saveField:(id)sender
{
self.fieldValue = theTextField.text;
NSArray *navigationStack = self.navigationController.viewControllers;
InvoiceAddViewController *parentController = (InvoiceAddViewController*)[navigationStack objectAtIndex:navigationSTack.count - 2];
[parentController updateField:self.fieldName value:self.fieldValue];
}
Edit: I should note this design is very brittle. A better way is to apply Model-View-Controller and create an object that represents a field and title value. Then your InvoiceAddViewController can pass instances of these objects to your detail controller, and as your detail controller changes them, these changes can be easily reflected in your other controllers.
Edit 2: Here is a hint of how it will work.
UITableViewCell *targetCell = [self.tableView cellForRowAtIndexPath:indexPath];
GenericTextFieldDetailViewController *dvController = [[GenericTextFieldDetailViewController alloc] initWithNibName:#"GenericTextFieldDetailViewController" bundle:[NSBundle mainBundle]];
dvController.dataObject = [self dataObjectForIndexPath:indexPath];
[self.navigationController pushViewController:dvController animated:YES];
[dvController release];
I'm assuming you've implemented a dataObjectForIndexPath: method. Presumably tableView:cellForRowAtIndexPath: would also use this method to configure its cells.
Now, you can eliminate both the saveField: and updateField: methods. In your InvoiceAddViewController, viewWillAppear: could be used to refresh your view like this:
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
[self.tableView reloadData]
}
There is a whole world of possibilities here. reloadData is a very heavy handed one. Experiment with stuff like KVO to make this more automatic.
In your detail controller, of course, don't forget to update the object, say in view will disappear to do something like
self.dataObject.fieldValue = theTextField.text;
This is just to get you started. There are a lot of possibilities and details to consider. You should really look at a lot of sample code, this pattern gets used a lot. The CoreDataBooks example on the developer portal uses a similar pattern, there are almost certainly others.
You should be using notification, KVO or delegation. Use the design patterns that fit passing data around on this platform. Even if you can make the call directly using one of these patterns will most certainly prove to be a better way of achieving this in an encapsulated manner.
This approach is just screaming for delegation. Create a protocol on your detail view controller, declare a method like
- (void)genericTextFieldDetailViewController:(GenericTextFieldDetailViewController *)controller didUpdateValue:(NSString *)value forField:(NSString *)field
Now when you're ready to send the data back you would just send this message to your delegate (the pushing view controller).
[self.delegate genericTextFieldDetailViewController:self didUpdateValue:newValue forField:passedInField]
Make sure that when you create and push the detail view controller, you assign yourself as it's delegate and implement that method to handle the incoming values. I think you'll find this approach way more flexible.
I had the same problem, but not with a table view. I wanted to change a value from the last view controller. I'm using Xcode 5:
{
NSArray *navigationStack = self.navigationController.viewControllers;
ViewController *control = [navigationStack objectAtIndex:([navigationStack count] -2)];
control.pagecont.currentPage = self.currIndex;
CGRect frame;
frame.origin.x = control.scroll.frame.size.width * control.pagecont.currentPage;
frame.origin.y = 50;
frame.size = control.scroll.frame.size;
[control.scroll scrollRectToVisible:frame animated:YES];
[self.navigationController popViewControllerAnimated:YES];
}

UINavigationController presents blank view

I have a very strange problem with UINavigationController on the iphone and I am banging my head against the wall on this.
Gist of it is I am executing a call to a server and when that call fails I swap out the current view with a view containing an error message. The code in question is called on the main thread by using performSelectorOnMainThread
What happens in practice is that on the device it shows a blank white screen about half the time. On the simulator it presents a blank screen every time leading me to think this is perhaps some kind of timing problem that is more prominent due to better processing speeds in a simulator. This works perfectly if I call the same function by clicking a button in the ui to display the page so I don't think its a problem with the code itself.
I have verified that the controller I am adding is in the navigation stack. Verified it is being called on the main thread, it is visible, the frame size and location are correct. I have tried explicitly setting the view to be visible, moved it to the front in its parent view and called setNeedsDisplay and even manually called drawRect. None of this works.
Any thoughts on what could be going on here? I am assuming it has something to do with the run loop but I can't figure it out. Help would be much appreciated. The relatively simple code in question is below
UINavigationController* navController = self.navigationController;
int count = [navController.viewControllers count];
NSMutableArray* controllers = [[NSMutableArray alloc] initWithCapacity:count];
for (int i=0; i<count; i++) {
if (self == [self.navigationController.viewControllers objectAtIndex:i]) {
[controllers addObject:newController];
}
else {
[controllers addObject:[self.navigationController.viewControllers objectAtIndex:i]];
}
}
[self.navigationController setViewControllers:controllers animated:YES];
[controllers release];
I really don't understand what you're doing there. Something like this won't work?
- (void)displayMyErrorVC {
MyErrorVC *errorVC = [[[MyErrorVC alloc] init] autorelease];
[self.navigationController pushViewController:errorVC animated:YES];
}
And then in your other thread, if you have an error:
[self performSelectorOnMainThread:#selector(displayMyErrorVC) withObject:nil waitUntilDone:NO];