I need to pass data of UILabel from ViewB to ViewA. My ViewA has a UILabel with some number. This number can be changed in ViewB which I open as a new UIViewController as below:
viewB = [[SettingsViewController alloc] initWithNibName:#"SettingsViewController" bundle:nil];
ViewB also has a UILabel to hold the same value. I tried to pass this value from ViewB to ViewA by assigning UILabel's like so:
viewB.countdownLabel = self.countdownLabel;
That didn't work. Thanks for suggestions...
i think what you want is:
viewB.countdownLabel.text = self.countdownLabel.text
Make sure viewB.countdownLabel is a retain property and it should work.
By saying "viewB.countdownLabel = self.countdownLabel;" you are simply making viewB's countdownLabel a reference to the original label, you're not copying their values. You need to do the following...
[viewB.countdownLabel setText:self.countdownLabel];
I would suggest that you use AppDelegate to pass the value across to any viewController (and read the documentation here).
GeneralAppDelegate*appDelegate=[[UIApplication sharedApplicaton] delegate];
myLocalProperty=appDelegate.someDataModelProperty;
or just use
viewB.countdownLabel.text = self.countdownLabel.text;
in your code.
KVO also can be used.
http://developer.apple.com/library/ios/#documentation/Cocoa/Conceptual/KeyValueObserving/KeyValueObserving.html#//apple_ref/doc/uid/10000177-BCICJDHA
Related
Rookie question: I am writing a program that will generate a specific string and then display it in a text window in a different view controller. I have been testing to ensure that the code in fact generates the string using NSLog commands and I know the code is working as intended. For some reason it is not transferring across the view controller and I cant figure out why. Any help? Here is a snippet of the code:
CreateStoryViewController.m
- (IBAction)makeStory:(id)sender
{
StoryLine *myStory =[[StoryLine alloc] init];
[myStory setStory];
self.story = myStory.plot;
NSLog(#"story is %#", self.story);//this is generating the correct story string
self.displayStoryController = [[BIDDisplayStoryViewController alloc] initWithNibName:#"DisplayStoryView" bundle:nil];
[self.view insertSubview:self.displayStoryController.view atIndex:1];
}
DisplayStoryViewController.m
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
BIDCreateStoryViewController *newStory = [[BIDCreateStoryViewController alloc] init];
NSLog(#"newStory.story is %#",newStory.story);//this generates null message
self.storyDisplay.text = newStory.story;
}
This is wrong. You're instantiating a new BIDCreateViewController object inside your second view controller. This is not the same as the original BIDCreateViewController object that pushed your second BIDDisplayStoryViewController.
You need to declare a string property in your BIDDisplayStoryViewController's header file.
Something like
#property (nonatomic, retain /*or strong, if using ARC*/) NSString *storyToDisplay;
Be sure to synthesize this in your implementation file as well.
When you create BIDDisplayStoryViewController inside your first view controller, you need to do it as follows:
self.displayStoryController = [[BIDDisplayStoryViewController alloc] initWithNibName:#"DisplayStoryView" bundle:nil];
self.displayStoryViewController.storyToDisplay = self.story;
Now inside your second view controller you can access this using self.myStory.
While this will solve your problem (and please do understand that it's not my intention to be rude here), I feel that there's a lack of understanding of how iOS (and OOP in general) works.
In your viewDidLoad method you are making a whole new story. This story is totally different from the one you made in the makeStory: method. You should add a StoryLine Property to DisplayStoryViewController.h, and set that after you init your displayStoryController.
make the intended variable a property type at .h file, so the other file can access it
i don't know if anyone is using this open source library for replacing UIPopovercontroller for an iPhone.
i'm trying to deploy the FPPopover into my project, everything is working like i want, but the problem is that i'm not able to return any value to my ViewController.
i'm trying this in didSelectRowAtIndexPath
myParentViewController *parentController =(myParentViewController*)self.parentViewController;
but the problem is that self.parentViewController is (null)
i have also another problem, how can i dismiss the FPPopoverController from within didSelectRowAtIndexPath.
I dismissed the view by adding a popoverView property to the table view controller that is popping up (in this case ATableViewController), and then assigning the FPPopoverViewController to that property. Like this:
ATableViewController *aTableViewController = [[ATableViewController alloc] init];
FPPopoverController *aPopoverController = [[FPPopoverController alloc] initWithViewController:aTableViewController];
aPopoverController.delegate = aTableViewController;
aTableViewController.popoverView = aPopoverController;
Then in didSelectRowAtIndexPath of aTableViewController you can just call:
[self.popoverView dismissPopoverAnimated:YES];
If you are trying to return values to the "parent"...since the parentViewController property is null here, you can just make your own property for it (let's call it "parentView"). So when setting up the above you would use:
aTableViewController.parentView = self;
Then you can access any of the properties of the parentView and return values from the aTableViewController that popped up. A bit of a workaround, but that's what I did...hope it helps!
I want to change dinamycally the ToolbarItems of my topviewcontroller.
I have a class that does my business logic and as a result returns an array of uibarbuttonitem.
so, i get the reference of the topviewcontroller like this:
ViewController *topVC = [appDelegate.navController topViewController];
now if i try to do:
[topVc setToolbarItems: myArrayofUibarbuttonItems];
But nothing happens.
What I'm missing?
Guess you could do it with the setItems function
[topVc.toolbar setItems:theArray];
just typed, not tested
[topVc.navigationController setToolbarItems:myArrayofUibarbuttonItems];
this should help u.. happy coding :)
I am using navigationcontroller. i have (Root,A,B,C,D) class. i want to sand a string test value Class D to Class A via popToViewController.
Please give me suggestion.
Thanks
UINavigationController maintain the list of all pushed controller in viewControllers and the root controller always reside at 0.
MyAController *myController = (MyAController *)[self.navigationController.viewControllers objectAtIndex:0];
myController.myText = #"My String" ;
[self.navigationController popToViewController:myController animated:YES];
You might want to rethink your design, but since you haven't given enough information for me to suggest how, you could just try this:
A *aController = (A *)[myNavController rootViewController];
[aController setMyString:#"your string here"];
[myNavController popToRootViewControllerAnimated:YES];
Make that string as property of class a then you need to access that object of the view A from navigation stack in class D.
And then access that property for using.
If Class A is rootView then jtbandes answers helps you otherwise pick it up from stack code some thing like this
if([self.navigationController.viewControllers count]>3)
A *aController=(A *)[self.navigationController.viewControllers objectAtIndex: [self.navigationController.viewControllers count]-4];
if your navigation is A->B->c->D
then you can access c by [self.navigationController.viewControllers count]-2 similarly B by -3 A by -4.
There are several approaches to achieve this.
Using Notifications.
Using Delegates.
Using Outlets/Properties.
You could also create a ControllerA instance var in your ControllerB and then pass the ControllerA (self) to ControllerB(ex: by a method) before call pushViewController from A to B. You can do the same from B to C...etc; i think the best solution is that of Jhaliya in case you want to work with navigationControllers.
I have an image in my RootViewController (which is selected from a UIImagePickerController), which I need to pass to a new view through a navigation controller. I have the following code that I use to pass strings to the next view:
//Get strings
NSString *text1 = line1.text;
NSString *text2 = line2.text;
NSString *text3 = line3.text;
NSString *text4 = line4.text;
//Create an GeneratedViewController and initialise it with given data
GeneratedViewController *gController = [[GeneratedViewController alloc] initWithNibName:#"GeneratedViewController" bundle:[NSBundle mainBundle]];
gController.text1 = text1;
gController.text2 = text2;
gController.text3 = text3;
gController.text4 = text4;
[self.navigationController pushViewController:gController animated:YES];
[gController release];
gController = nil;
How might I pass an image to the GeneratedViewController?
Thanks,
Jack
The easiest solution would be to create a property of type UIImage on GeneratedViewController.
Then after creating and initializing the GeneratedViewController but before pushing it onto the navigationController you will need to set the image property on the gController to the selected image.
A property on the controller, just like the text is set
In a method, or the initializer
through a notification (NSNotificationCenter). This is a bit more advanced.
Through delegation, where the first controller is a datasource delegate on the Generated Controller. This allows the second controller to get what it needs, whenever it wants.
Which method to use depends on how the controllers are created, when the image can change, and how many different pieces of data the second controller needs - one or two bits, properties work fine. More than that, I tend to use delegation.