I'm trying to dynamically change a UISwitch with the method [self.mySwitch setOn:YES animated:YES];
The state change as well in the code so that the mecanisme is working fine but in the view the state has not change. So I get a UISwitch shown as OFF and working as it was as ON.
When I tap on it, the switch became ON. So I have to tap it twice to launch the inCaseOff part of code.
I hope this is clear enough.
[EDIT]
This is the code you have asked
- (void)viewDidLoad
{
[self manageTheSwitch];
}
- (void) manageTheSwitch{
self.mySwitch = [[UISwitch alloc]init];
if(randomObject != nil){
[self.mySwitch setOn:YES animated:YES];
}else{
[self.mySwitch setOn:NO animated:YES];
}
}
You're programmatically setting a different UISwitch to the one shown in your view. You shouldn't have to do [[UISwitch alloc]init] at all, instead you should retrieve it through an IBOutlet property in your controller (wired up to your view in IB).
Assuming you did wire up mySwitch, then all you need to do is remove this line:
self.mySwitch = [[UISwitch alloc]init];
Your problem is, that you're instantiating a new button in your manageTheSwitch method rather than accessing the one you created in the storyboard. Just eliminate that alloc init.
try using the "selected" property UISwitch inherits from UIControl:
self.mySwitch.selected = YES;
Related
i have a UIViewController with UITableView, when the tableView is empty i want to show another view so i am using this
[self.tableView setHidden:YES];
NoKidsViewController *noKids = [self.storyboard instantiateViewControllerWithIdentifier:#"NoKidsView"];
[self.view addSubview:noKids.view];
all is fine, i'm able to see the view. but when i tap on one of the buttons in it i'm getting the EXC_BAD_ACCESS EXC_I386_GPFLT error.
//NoKidsViewController
- (IBAction)addNewKid:(id)sender {
AddKid *addKidController = [self.storyboard instantiateViewControllerWithIdentifier:#"AddKid"];
[self.navigationController pushViewController:addKidController animated:YES];
}
- (IBAction)saleSpot:(id)sender {
SaleSpot *saleSpotController = [self.storyboard instantiateViewControllerWithIdentifier:#"AddKid"];
[self.navigationController pushViewController:saleSpotController animated:YES];
}
i searched the net over 3 hours trying to find any solution w/o success. what could cause that error? and how can i fix it?
The noKids controller is going out of scope and being deallocated. This is what is often referred to as a zombie object.
You need to add the noKids controller to the childViewControllers of the containing controller.
NoKidsViewController *noKids = [self.storyboard instantiateViewControllerWithIdentifier:#"NoKidsView"];
[self addChildViewController:noKids];
[self.view addSubview:noKids.view];
[noKids didMoveToParentViewController:self];
This will retain the NoKidsViewController as well as allow the view controller methods to pass down to it. For more information on creating your custom container view controller:
https://developer.apple.com/library/ios/featuredarticles/ViewControllerPGforiPhoneOS/CreatingCustomContainerViewControllers/CreatingCustomContainerViewControllers.html
Major head-scratcher all day on this one :-(
I have an instance of a UIPageViewController that does not appear to be firing the delegate method:
-(UIPageViewControllerSpineLocation)pageViewController:(UIPageViewController *)pageViewController
spineLocationForInterfaceOrientation:(UIInterfaceOrientation)orientation
I have tried various methods of displaying the UIPageViewController and have settled on a programatic approach (as opposed to a Storyboard one) that appears to be working correctly, with one exception... when rotating the iPad to landscape the spine does not appear mid-point as expected. I simply cannot find out why the delegate method does not get called.
Code Explanation (simplified for example)
Consider three classes as follows:
RootViewController - loaded when the app starts
PageViewController - loaded by RootViewController upon user initiation
PageContentViewController - loaded by PageViewController when pages are needed
Fairly self-explanatory. The RootViewController is loaded by the app upon launch. When the user taps an image within this view controller's view (think magazine cover opening a magazine) it launches the PageViewController as follows:
PageViewController *pvc = [[PageViewController alloc] initWithNibName:#"PageView"
bundle:[NSBundle mainBundle]];
pvc.view.frame = self.view.bounds;
[self.view addSubview:pvc.view];
In the actual app there is animation etc to make the transition all nice, but essentially the PageViewController's view is loaded and takes fullscreen.
PageViewController
This is the workhorse (only relevant methods shown). I have tried various examples from the infinite world of Google and written directly from the Apple docs...
#interface PageViewController : UIViewController <UIPageViewControllerDelegate, UIPageViewControllerDataSource>
#property (nonatomic, strong) UIPageViewController *pageViewController;
#property (nonatomic, strong) NSMutableArray *modelArray;
#end
#implementation TXCategoryController
-(void)viewDidLoad
{
[super viewDidLoad];
// Simple model for demo
self.modelArray = [NSMutableArray alloc] init];
for (int i=1; i<=20; i++)
[self.modelArray addObject:[NSString stringWithFormat:#"Page: %d", i]];
self.pageViewController = [[UIPageViewController alloc]
initWithTransitionStyle:UIPageViewControllerTransitionStylePageCurl
navigationOrientation:UIPageViewControllerNavigationOrientationHorizontal options:nil];
self.pageViewController.delegate = self;
self.pageViewController.dataSource = self;
PageContentViewController *startupVC = [[PageContentViewController alloc] initWithNibName:#"PageContent" bundle:nil];
startupVC.pageLabel = [self.modelArray objectAtIndex:0];
[self.pageViewController setViewControllers:[NSArray arrayWithObject:startupVC]
direction:UIPageViewControllerNavigationDirectionForward
animated:NO
completion:nil];
[self addChildViewController:self.pageViewController];
[self.view addSubview:self.pageViewController.view];
[self.pageViewController didMoveToParentViewController:self];
self.pageViewController.view.frame = self.view.bounds;
self.view.gestureRecognizers = self.pageViewController.gestureRecognizers;
}
-(UIViewController *)pageViewController:(UIPageViewController *)pageViewController
viewControllerBeforeViewController:(UIViewController *)viewController
{
// Relevant code to add another view...
}
-(UIViewController *)pageViewController:(UIPageViewController *)pageViewController
viewControllerAfterViewController:(UIViewController *)viewController
{
// Relevant code to add another view...
}
-(UIPageViewControllerSpineLocation)pageViewController:(UIPageViewController *)pageViewController
spineLocationForInterfaceOrientation:(UIInterfaceOrientation)orientation
{
// Setting a break point in here - never gets called
if (UIInterfaceOrientationIsPortrait(orientation))
{
// Relevant code to create view...
return UIPageViewControllerSpineLocationMin;
}
// Relevant code to create 2 views for side-by-side display and
// set those views using self.pageViewController setViewControllers:
return UIPageViewControllerSpineLocationMid
}
#end
This all works perfectly well as I mentioned earlier. The PageViewController's view gets shown. I can swipe pages left and right in both portrait and landscape and the respective page number appears. However, I don't ever see two pages side-by-side in landscape view. Setting a breakpoint in the spineLocationForInterfaceOrientation delegate method never gets called.
This is such a head-scratcher I have burned out of ideas on how to debug/solve the problem. It almost behaves like the UIPageViewController isn't responding to the orientation changes of the device and therefore isn't firing off the delegate method. However, the view gets resized correctly (but that could be just the UIView autoresizing masks handling that change).
If I create a brand new project with just this code (and appropriate XIb's etc) it works perfectly fine. So something somewhere in my actual project is causing this. I have no idea where to continue looking.
As usual, any and all help would be very much appreciated.
Side Note
I wanted to add the tag 'uipageviewcontrollerspinelocation' but couldn't because it was too long and I didn't have enough reputation (1500 required). I think this is a devious ploy on Apple's part to avoid certain tags in Stackoverflow... ;-)
Finally found the problem. It was something of a red herring in its symptoms, but related just the same.
Putting a break point in the shouldAutorotateToInterfaceOrientation: method was a natural test to see if the UIViewController was even getting a rotation notification. It wasn't which led me to Apple's technical Q&A on the issue: http://developer.apple.com/library/ios/#qa/qa1688/_index.html
The most relevant point in there was:
The view controller's UIView property is embedded inside UIWindow but alongside an additional view controller.
Unfortunately, Apple, in its traditional documentation style, doesn't provide an answer, merely confirmation of the problem. But an answer on Stack Overflow yielded the next clue:
Animate change of view controllers without using navigation controller stack, subviews or modal controllers?
Although my RootViewController was loading the PageViewController, I was doing it as a subview to the main view. This meant I had two UIViewController's in which only the parent would respond to changes.
The solution to get the PageViewController to listen to the orientation changes (thus triggering the associated spine delegate method) was to remove addSubview: and instead present the view controller from RootViewController:
[self presentViewController:pac animated:YES completion:NULL];
Once that was done, the orientation changes were being picked up and the PageViewController was firing the delegate method for spine position. Only one minor detail to consider. If the view was launched in landscape, the view was still displaying portrait until rotated to portrait and back to landscape.
That was easily tweaked by editing viewDidLoad as follows:
PageContentViewController *page1 = [[PageContentViewController alloc] initWithNibName:#"PageContent" bundle:nil];
NSDictionary *pageViewOptions = nil;
NSMutableArray *pagesArray = [NSMutableArray array];
if (IS_IPAD && UIInterfaceOrientationIsLandscape(self.interfaceOrientation))
{
pageViewOptions = [NSDictionary dictionaryWithObject:[NSNumber numberWithInt:UIPageViewControllerSpineLocationMid]
forKey:UIPageViewControllerOptionSpineLocationKey];
PageContentViewController *page2 = [[PageContentViewController alloc] initWithNibName:#"PageContent" bundle:nil];
[pagesArray addObject:page1];
[pagesArray addObject:page2];
}
else
{
[pagesArray addObject:page1];
}
self.pageViewController = [[UIPageViewController alloc] initWithTransitionStyle:UIPageViewControllerTransitionStylePageCurl
navigationOrientation:UIPageViewControllerNavigationOrientationHorizontal
options:pageViewOptions];
self.pageViewController.delegate = self;
[self.pageViewController setViewControllers:pagesArray
direction:UIPageViewControllerNavigationDirectionForward
animated:NO
completion:NULL];
Job done and problem solved.
recently I started using storyboard and I've the following situation: I want to set the text of an UILabel from the AppDelegate. So I created an instance of my ViewController
UIStoryboard *mainStoryboard = [UIStoryboard storyboardWithName:#"MainStoryboard"
bundle: nil];
ViewController *controller = (ViewController*)[mainStoryboard
instantiateViewControllerWithIdentifier: #"mainViewController"];
myViewController = controller;
[window addSubview:myViewController.view];
[window makeKeyAndVisible];
and called the following method from the delegate
- (void) updateParameterLabel:(NSString *)parameter {
NSLog(#"URL-2: %#", parameter);
parameterLabel.text = parameter;
}
But the parameter is not shown in the UI.
Another think, which is kind of strage:
- (void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
NSLog(#"View did Appear");
}
The "View did appear" is logged twice ...
Any hints?
Regards,
Sascha
Setting the text of a UILabel from your application delegate isn't great design. Your view controllers should be managing the content of your views, hence their name. Typically your storyboard is instantiated automatically, and you don't need any of the storyboardWithName et code you've got, assuming you're working with Apple's default templates.
Maybe think about re-architecting your application to follow the 'model-view-controller' pattern more strictly, and also look at how Apple instantiate storyboards automatically (just create a new storyboard project in XCode to see this).
If you still want to make it work, make the UILabel a property of your viewcontroller and set the label by using
In delegate :
- (void) updateParameterLabel:(NSString *)parameter {
NSLog(#"URL-2: %#", parameter);
[myViewController updateParemeter:parameter];
}
In myViewController:
- (void) updateParameterLabel:(NSString *)parameter {
NSLog(#"URL-2: %#", parameter);
parameterLabel.text = parameter;
[self.view setNeedsDisplay];//edit
}
So use the viewController to update your label. Of course you need the label as a property in your viewController
For what I see you are trying to update the label before it appears, so why don't you try calling your updateLabel method in the viewWillAppear, it would be something like this
-(void)viewWillAppear:(BOOL)animated{
[self updateParameterLabel:#"Some Text"];
[super viewWillAppear:YES];
}
And updateParameterLabel has to be implemented in the viewController.
I am making a simple app to display drink details, and now I am trying to add a view that allows the user to input their own drink. I already created a view to display the details, and now I am just passing the view into another controller to make the add drink view. Problem is, when I try to add a "cancel" and "save" button, it doesn't appear, although the code complies without any errors. I have attached code as reference.
This is the code that makes the new view, when the add button is pressed. (I made an add button that works, and it pulls up the nav bar)
- (IBAction)addButtonPressed:(id)sender {
AddDrinkViewController *addViewController = [self.storyboard instantiateViewControllerWithIdentifier:#"DetailSecond"];
UINavigationController *addNavController = [[UINavigationController alloc] initWithRootViewController:addViewController];
[self presentModalViewController:addNavController animated:YES];
NSLog(#"Add button pressed!");
This is the code from the addviewcontroller implementation file:
- (void)viewDidLoad
{
[super viewDidLoad];
self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemCancel target:self action:#selector(cancel:)];
self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemSave target:self action:#selector(save:)];
}
- (IBAction)save:(id)sender {
NSLog(#"Save Pressed");
[self dismissModalViewControllerAnimated:YES];
}
- (IBAction)cancel:(id)sender{
NSLog(#"Cancel Pressed");
[self dismissModalViewControllerAnimated:YES];
}
I have imported the header from the addview into the root controller, so I don't think that is the problem, do any of you guys see anything that's wrong?
Just change the line
[self presentModalViewController:addNavController animated:YES];
to
[self presentViewController:navigationController animated:YES completion:nil];
and see the magic. I also tested the code
My advice to you is to create a template for the view before you run through any code in the XIB file of your app. Rather than trying to set each button after allocating a brand new view, setting a new one in the XIB before-hand allows you to link each element with the app and make sure it looks just right before you debug.
Simply go into your "[Your-App-Name]viewController.xib" and drag a view from the objects library to the pane on the left. From here add each of your elements and position them where you want on the view. Now in the "[Your-App-Name]viewController.h" file, add IBOutlets for each element that you need to change, and add IBActions for each of the buttons. Also create an IBOutlet for the new view.
IBOutlet UIView* addDrinkView;
Back in the XIB file, use files owner to link each outlet to each element and each method to each button. Make sure you link the IBOutlet
Now in your "[Your-App-Name]viewController.m" file, you can define each button method and all you need to do to access the new view and dismiss it are the following:
-(IBAction)openAddView
{
[self setView:addDrinkView];
}
-(IBAction)saveButtonPressed
{
[self setView:view];
//save code goes here
}
-(IBAction)cancelButtonPressed
{
[self setView:view];
//cancel code goes here
}
This should be much easier than trying to position everything in code.
Hope this helps!
I'd like to know how to open the camera inside of a pre-defined frame (not the entire screen). When the view loads, I have a box, and inside it, I want to display what the camera sees. I don't want to snap a picture, just basically use the camera as a viewfinder. I have searched this site and have not yet found what I'm looking for. Please help.
Thanks!
Thomas
Update 1:
Here is what I have tried so far.
1.) I added UIImageView to my xib.
2.) Connect the following outlet to the UIImageView in IB
IBOutlet UIImageView *cameraWindow;
3.) I put the following code in viewWillAppear
-(void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
UIImagePickerController *picker = [[UIImagePickerController alloc] init];
picker.delegate = self;
picker.sourceType = UIImagePickerControllerSourceTypeCamera;
[self presentModalViewController:picker animated:YES];
NSLog(#"viewWillAppear ran");
}
But this method does not run, as evident by the absence of NSLog statement from my console. Please help!
Thanks,
Thomas
Update 2:
OK I got it to run by putting the code in viewDidLoad but my camera still doesn't show up...any suggestions? Anyone....? I've been reading the UIImagePickerController class reference, but am kinda unsure how to make sense of it. I'm still learning iPhone, so it's a bit of a struggle. Please help!
- (void)viewDidLoad
{
[super viewDidLoad];
// Create a bool variable "camera" and call isSourceTypeAvailable to see if camera exists on device
BOOL camera = [UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera];
// If there is a camera, then display the world throught the viewfinder
if(camera)
{
UIImagePickerController *picker = [[UIImagePickerController alloc] init];
// Since I'm not actually taking a picture, is a delegate function necessary?
picker.delegate = self;
picker.sourceType = UIImagePickerControllerSourceTypeCamera;
[self presentModalViewController:picker animated:YES];
NSLog(#"Camera is available");
}
// Otherwise, do nothing.
else
NSLog(#"No camera available");
}
Thanks!
Thomas
Update 3:
A-HA! Found this on the Apple Class Reference.
Discussion
The delegate receives notifications
when the user picks an image or movie,
or exits the picker interface. The
delegate also decides when to dismiss
the picker interface, so you must
provide a delegate to use a picker. If
this property is nil, the picker is
dismissed immediately if you try to
show it.
Gonna play around with the delegate now. Then I'm going to read on wtf a delegate is. Backwards? Whatever :-p
Update 4:
The two delegate functions for the class are
– imagePickerController:didFinishPickingMediaWithInfo:
– imagePickerControllerDidCancel:
and since I don't actually want to pick an image or give the user the option to cancel, I am just defining the methods. They should never run though....I think.
add
[picker
dismissModelViewControllerAnimated:YES];
to delegate method bodies.
It will dismiss the view.