simple question of pushViewController - iphone

messagecontroller is nothing but object of initialize nib file.
[self.navigationController pushViewController:messageController animated:YES];
this statement executes in normal condition
this statement also works on state maintainace testing ,
this line executes properly but not open new view ,why?

Calling this method call does not push a new view?
If this is the question you should ask yourself some questions:
Is self having an
UINavigationController? Make sure
self is a view controller
inside a navigation controller.
Is messageController initialized
correctly? Like this for example (if
messageController is an ivar):
messageController = [[MyViewControllerClass alloc] initWithNibName:#"MyViewControllerClassNibName" bundle:nil];

Related

Trying to go from one view controller to another in a story board

I'm writting my first app using a storyboard. Before I had the following code to go from one view controller to another. But..this code needs a NibName. How would I do this going from screens created in a storyboard?
if (mDisplayCard==nil)
{
mDisplayCard = [[cDisplayCard alloc]
initWithNibName:#"cDisplayCard"
bundle:[NSBundle mainBundle]];
}
// [ mDisplay SetUp];
[self.navigationController pushViewController: mDisplayCard animated:YES];
A line like the following will instantiate a new view controller from a storyboard:
UIViewController *newViewController = [self.storyboard instantiateViewControllerWithIdentifier:#"<identifier-from-storyboard>"];
It is assumed that your current view controller was instantiated from the same storyboard, so that self.storyboard is not nil. For the view controller that you want to instantiate, you'll have to make sure that you set a storyboard ID for it, which is what you'll put in for the identifier.

XCode5 self.navigationController pushViewController:animated: doesn't open the new viewcontroller

I'm not sure why but in Xcode 5 working on a project of IOS6.1 I have a button connected to a IBAction in which I'm trying to navigate to a new view controller.
I've tried two different codes to create the viewController and then push it to the navigation in both cases the view controller is not nil and both cases the viewController doesn't appear.
first try: with story Id - I've set the story id of the view controller to imageCapture and set the class to VSImageCaptureViewController
VSImageCaptureViewController* imageCaptureViewController = (VSImageCaptureViewController*)([self.storyboard instantiateViewControllerWithIdentifier:#"imageCapture"]);
[self presentViewController:imageCaptureViewController animated:NO completion:nil];
second try: with the name of the viewcontroller
VSImageCaptureViewController *imageCaptureViewController = [[VSImageCaptureViewController alloc] initWithNibName:#"VSImageCaptureViewController" bundle:nil];
[self.navigationController pushViewController:imageCaptureViewController animated:YES];
can you see something wrong or do you think I forgot to initialize something
Check to see if self.navigationController is nil.
If it is nil that means that you are not running within the context of a UINavigationController (the system sets this property for you when the UIViewController is added to a nav stack).
If this is the case then you have not properly set up a UINavigationController.
Note that you can not set the navigationController property yourself. The systems sets it for you when the UIViewController is added to a UINavigationController's stack (and sets it to nil when it is removed from the stack).
To set this up you will usually create a UINavigationController instance right after you create your main view controller.
UIViewController *mainViewController = ...;
UINavigationController *mainNavController = [[UINavigationController alloc] initWithRootViewController:mainViewController];
// now present the mainNavController instead of the mainViewController
If you are using storyboards you would drag out a UINavigationController instance and replace the default root view controller with an instance of your mainViewController.

problem in displaying a string in a textbox

Hi to all,
I passed a variable from first.m to seViewController.m. I'm able to print that variable using NSLog(#variable) but I'm unable to use textField.text=variable. How to print that variable in a textbox?
First.m
-(void)buttonPressed01
{
seViewController *seView = [[seViewController alloc] init];
[seView insert:myString];
[self.navigationController popViewControllerAnimated:YES];
}
seviewcontroller.m
-(void)insert:(NSString*) myString
{
NSLog(#"%#",myString);
textField.text=[NSString stringWithFormat:#"%#",myString];
}
seViewController *seView = [[[seViewController alloc] initWithNibName:#"seViewController" bundle:nil] autorelease];
[seView insert:String];
[[self navigationController] pushViewController:seView animated:YES];
seviewcontroller.m
-(void)insert:(NSString*) myString
{
NSLog(#"%#",myString);
textField.text=myString;
}
Until your seViewController is loaded you can not use its outlets, here you are using textField. It won't set text because after seViewController *seView = [[seViewController alloc] init]; the view is initialized but still you need to load its view in memory in order to use its outlet. so if you are using its view then after addingSubview, or presenting modalView or, pushing it on navigation stack call that method.
or else you should have a string in seviewcontroller which you will set and when controller's will be loaded in memory viewDidLoad just do what you are doing right now in insert method, set TextField's text.
Also, I am not sure what you want to do with seView? why you are creating new instance and not using it ? May be you have created this controller earlier and you want to change that controller's textField text not the new one. Then in that case you should refer that controller not this one because its totally different object.
Thanks
When you pop from stack it loads the instance of the view controller you pushed in to stack. Here you created a new instance and set the text field and loads the instance in the stack. Thats why text field does not show the value to set. If you want to pass the value to the class you nee to pass the value using some singleton class or app delegate.
I think its not working because you are passing this variable to a new instance of your seViewController while you are popping it in the next line. You have to get the same instance as -
seViewController *seView = (seViewController*)[self parentViewController];
[seView insert:myString];
[self.navigationController popViewControllerAnimated:YES];
You can use this one if what I understood is correct,
you can retrieve the array of viewControllers from the navigation controller.
You dont need to initialize the view controller and this wont work as explained above.

A couple of problems customizing Apples MultipleDetailViews Example

I have been trying to add/implement this example to my existing Split View app tests.
Apple Example
I what to use the concept of replacing the detail view or right view, otherwise my app will be different. It is this difference that is causing my problems.
I have a rootviewcontroller or left view and upon choosing something here a new view is pushed onto this view. Upon choosing something in this "pushed view" I want to change the detail view or right hand view. This is the difference to apples example where the rootview does not have a pushed view on it and thus references are not broken.
Below is my change code - the new View DVCases is being initialized but the didload is not happening.
The issues are learner issues to do with my classes.
This below code is in my RootViewController implementation code but my reference to splitviewcontroller is not working if there is a new view pushed.
Second self.navigationcontroller is not correct because I have pushed a second view to the rootviewcontroller.
To centralize and simplify the code what I have done is from the delegate of the pushed view in the didselect event i call a method found in the rootviewcontroller passing the index as a parameter. The code for my custom method contains what is below.
So my question is how do I do this in my situation where I have pushed other views onto the rootview or left side. It appears that after pushing a view the reference to splitviewcontroller is gone and self.navigationcontroller is also gone/or wrong.
UIViewController <SubstitutableDetailViewController> *detailViewController = nil;
if (value == 0) {
DVCases *newDetailViewController = [[DVCases alloc] initWithNibName:#"DVCases" bundle:nil];
detailViewController = newDetailViewController;
}
// Update the split view controller's view controllers array.
NSArray *viewControllers = [[NSArray alloc] initWithObjects:self.navigationController, detailViewController, nil];
splitViewController.viewControllers = viewControllers;
[viewControllers release];
// Dismiss the popover if it's present.
if (popoverController != nil) {
[popoverController dismissPopoverAnimated:YES];
}
// Configure the new view controller's popover button (after the view has been displayed and its toolbar/navigation bar has been created).
if (rootPopoverButtonItem != nil) {
[detailViewController showRootPopoverButtonItem:self.rootPopoverButtonItem];
}
[detailViewController release];
I would appreciate any tips or help you might have.
Initialization of any viewcontroller class does not mean that it will make call to viewDidLoad method.
viewDidLoad method will only be called when you load view of that viewController. Generally we do it either by following methods.
1. Pushing it on navigation stack.
2. Presenting it using modal transition.
3. Adding it on some other view using [someView addSubView:controller.view];
4. Selecting any tabBar item for the first time Or tapping tabBar Item twice.
there may be some other scenarios.
But right now in your code I don't see any of this element.
Initialization means you are calling the direct method for intialization(calling its constructor) like here in above code initWithNibName will call this method of DVClass not any other(until this method had call for other methods inside it).
Thanks
As I am learning to properly code - my problems centres around that.
The above code is perfect as long as you call it using the same instance. I was not. Thus it was not working.
In the end I made my RootViewController a delegate for a method that has the above code. Thus when in another view - this view can call this method and the proper or real instance of RootViewController will implement it.

a sub viewcontroller notify the root viewcontroller to load another sub viewcontroller

I have a project in which the root viewcontroller call multi viewcontrollers. There is button on a sub viewcontroller's view, when I press the button, I hope it notify the root view controller to load another sub viewcontroller.
//the function in this viewcontroller
-(IBAction)submitButtonPressed:(id)sender;
{
[self.parentViewController notifyLoadAnotherViewContrller ] ;
}
//the function in root viewcontroller
-(void) notifyLoadAnotherViewContrller
{
Submit *tController = [[AnotherViewController alloc] initWithNibName: #"AnotherViewController" bundle:nil];
self.vanotherViewController = tController;
[tController release];
[self.view insertSubview:tController.view atIndex:10];
}
but this does not works
I set the breakpoint in function -(void) notifyLoadAnotherViewContrller
it does not work I checked the function name, no problem.
What is reason I am doing wrong?
Welcome any comment
Best Regards
interdev
So some standard debugging... Set a breakpoint in submitButtonPressed: to make sure your IBAction is properly connected. Examine parentViewController to make sure it's what you expect.
Since the method is not getting called, then your button is either not connected in Interface Builder or your parentViewController is nil, which will silently ignore the method call.