I'm trying to create a navigation view in the Interface Builder. It's not in the MainWindow.xib, so the relevant sample project on the Apple Dev. site is useless.
The most logical (and cleanest) way to approach this seems to create a Xib-file where the File's Owner is a subclass of UINavigationController - however, I cannot get this to work at all in IB, (because UINavigationController acts as a folder, and File's Owner doesn't, even when I change the class).
Alternatively, I've got a Xib-file where the File's owner is a subclass of a normal ViewController (VCA). I've added a NavigationController with a ViewController that's another subclass of UIViewController (VCB), and I've specified a Xib view for this ViewController. But I have no idea how to specify the view of VCA in IB, and my attempts to do this programmatically haven't worked.
Please help!
I've had trouble doing things like this when I was getting started and the most workable approach I came up with was to create the UINavigationController programmatically. I adapted my code from the iPhone "utility" Xcode template. Here's a bit of it that will hopefully get you going: (edited for brevity; self is a UIViewController)
self.menuViewController = [[[MenuViewController alloc]
initWithNibName:nil bundle:nil] autorelease];
self.navController = [[UINavigationController alloc]
initWithRootViewController:self.menuViewController];
self.navController.navigationBar.barStyle = UIBarStyleBlackOpaque;
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:1];
[self.view addSubview:self.navController.view];
[UIView commitAnimations];
Related
I know different versions of this question has been asked before but I'm really stuck here. I'm trying to get my app to push a new view from my app delegate when getting:
-(void)application:(UIApplication *)application didReceiveLocalNotification:(UILocalNotification *)localNotif {
And I put the following code in there:
MyViewController *myViewController = [[MyViewController alloc]init];
nvcontrol = [[UINavigationController alloc] initWithRootViewController:myViewController];
[nvcontrol.navigationBar setTintColor:[UIColor blackColor]];
self.window.rootViewController = nvcontrol;
and from this, I get a black view (which myViewController should not have) with a black navigation bar.
What am I doing wrong here?
As I've outlined above, you can use storyboard to set the initial view controller.
Note that if you have a view controller set up in storyboard and then you create a view controller in the application delegate, the view controller you created won't look like your one in storyboard. This is because you are making an instance of the CLASS, but the program has no way to associate this with your layout.
In one of my ViewControllers (ViewController A), I have the following code:
AlertViewController *aViewController = [[AlertViewController alloc] initWithNibName:#"AlertViewController" bundle:nil];
[self.view addSubview:[aViewController view]];
[self.view bringSubviewToFront:[aViewController view]];
And in AlertViewController, I have a button and when the user clicks on it, I have:
[self.view removeFromSuperview];
Whenever I click the button, the result is EXC_BAD_ACCESS.
I'm unable to figure out the problem. My project is using ARC and ViewController A is part of a navigation controller stack if that info helps.
The problem here is that the UIView doesn't own its UIViewController. In the first block of code you held the UIView around by adding it to a subview, but let the UIViewController go away. The UIView from a UIViewController is special, you can't let this happen.
Make sure the UIViewController that created the UIView lives as long as the view does.
I am building a cocoa application with one main window controller with a xib. That xib contains many custom view classes. I would like to add an NSViewController to the xib, but i'm running into some trouble.
In interface builder I can drag the NSViewController into the xib, assign it its custom controller class, and assign its view to the appropriate view in the xib. Here's the problem: neither the initWithNibName:Bundle: or loadView get called.
What am I missing?
EDIT:
People seem to be misunderstanding the question so I'll clarify.
The window already has a view controller. What I am seeking to do is assign separate view controllers to several of the subviews. I need to know how to associate my NSViewController subclass with the appropriate NSView subclass (which is a child of the main window).
Or in other words, I am trying to use multiple NSViewController subclasses to controll many different custom views (one each) within a single .xib file. Those controllers and subviews have their own .xibs which should ultimately become visible in the same window.
The pattern I use for NSViewController is to have a xib per view controller. Then, when you need that view controller you alloc it and use the initWithNibName:Bundle: method. As soon as you use its view, loadView will get called.
Example:
self.editViewController = [[[MyEditViewController alloc] initWithNibName:#"MyEditViewController" bundle: nil] autorelease];
[self.window setContentView: editViewController.view];
I used to get stuck with that as well and gave up on that thing - the blue circle with a white bordered view in it from the IB palette. I now create my controllers from code and only set a reference in IB to the owning controller class via the file owner: right click the file owner, enter the class name in the Identity inspector and then make a connection from the file's owner view to the view.
In your code you then do at an appropriate initialisation point:
[self setMyViewController = [[MyViewController alloc] initWithNibName: #"MyView" bundle: [NSBundle mainBundle]]
For your specific case this could be in windowDidLoad method when your window is loaded from its nib and ready for work. You can then add the view to your windows content view. Also you might want to consider to have a 1:1 relation between view and view controller. It makes life a lot easier in terms of maintenance.
EDIT: Like #pcperini suggests in his comments you can use the palette component, but you'll still need to instantiate the controller in your code. If you want to use the palette component, create a property in your main controller or AppDelegate:
#property (...) MyViewController *myViewController;
Add the line of code to actually create the controller (see above). Then, using the bindings inspector bind the palette component to the myViewController property.
So, what you are missing is that you are actually not instantiating the controller object.
EDIT 2: Here's the code (the awakeFromNib is the method of the top controller). It creates two child controllers each handling a different subview:
- (void) awakeFromNib {
[[self startEndTopicHeader] setHeader: #"Event timeline boundary"];
[[self startDateHeaderView] setHeader: #"Event (start) date"];
[[self endDateHeaderView] setHeader: #"Event end date"];
[self setStartDateViewController: [[EventTimeViewController alloc] initWithNibName: #"EventTimeView" bundle: [NSBundle mainBundle]]];
[[[self startDateViewController] view] setFrame: [[self dummyStartView] bounds]];
[[self dummyStartView] addSubview: [[self startDateViewController] view]];
[[self startDateViewController] setParentController: self];
[self setEndDateViewController: [[EventTimeViewController alloc] initWithNibName: #"EventTimeView" bundle: [NSBundle mainBundle]]];
[[[self endDateViewController] view] setFrame: [[self dummyEndView] bounds]];
[[self dummyEndView] addSubview: [[self endDateViewController] view]];
[[self endDateViewController] setParentController: self];
}
Lets say that I have 4 view controllers (call them FirstView,SecondView,ThirdView,FourthView) which are created programmatically and all are in separate files:
In AppDelegate.m didFinishLaunchingWithOptions method I have these lines of code
self.rootViewController = [[rootViewController alloc]initWithNibName:#"rootViewController" bundle:nil];
self.window.rootViewController = self.rootViewController;
In rootViewController.m loadview method I have
self.view = [[UIView alloc]initWithFrame:[UIScreen mainScreen].applicationFrame];
self.firstView = [[FirstView alloc]init];
[self.view addSubview:self.firstView.view];
That code works fine - first view is displayed.
Let's continue
In FirstView.m switchViews method
NOTE: Please see the comments in code
self.secondView = [[SecondView alloc] initWithNibName:#"SecondView" bundle:nil];
// I think here secondView is added to rootViewController - right ?
[self.view.superview addSubview:self.secondView.view];
// Here first view is removed from rootViewController - right ?
[self.view removeFromSuperview];
Here is how I add/remove views.
Is this approach correct?
Can you recommend a better solution?
I have read about UINavigationController, but I don't think it could be a solution in this case.
You say:
I have 4 views (call them FirstView ...
Then you say:
[self.view addSubview:self.firstView.view];
Which makes me think that FirstView isn't actually a UIView - as you claim it is. Instead, it's probably a UIViewController - a different beast altogether.
If my suspicion is correct - then you are "off-track" so to speak.
Going beyond that to your sample code snippet:
self.secondView = [[SecondView alloc] initWithNibName:#"SecondView" bundle:nil];
// I think here secondView is added to rootViewController - right ?
[self.view.superview addSubview:self.secondView.view];
// Here first view is removed from rootViewController - right ?
[self.view removeFromSuperview];
This is definitely not a great idea. Here's why:
First: your view controller doesn't explicitly "know" anything about the superview you are so casually inserting and removing subviews to/from - so it shouldn't do that. You may, alternatively, create your own view and insert/remove subviews from that - which would not only be perfectly acceptable but also common practice.
Second: if these are actually UIViewControllers like I think they are - then you are not properly handling hooking them up to the UIViewController event chain - which means methods on these subclasses like viewDidAppear: or viewDidUnload will not fire.
From what I see in your code, UINavigationController seems like it would help. If you don't want a navigation bar, you can definitely hide it, but the methods in UINavigationController should help you with switching views.
If your views only need to display temporarily, you could also use Modal View controllers. An example of Modal View controllers can be found here.
If you haven't already, check out the View Controller Programming Guide from Apple.
I am trying to work my way through basic iPhone programming and I have a good basic understanding of how Interface Builder works, so I decided to try my hand at doing the views programmatically. I have gone through the ViewController Apple guide and searched everywhere and I cannot seem to find a solution to my problem. This leads me to believe it is a very simple solution, but I am just really banging my head against the wall. Basically all I am trying to do is create a view that gets main window as a subview. I know that if self.view is not defined then the loadView method is supposed to be called, and everything is supposed to be set up there. Here is the current state of my code:
The delegate:
- (void)applicationDidFinishLaunching:(UIApplication *)application {
StartMenuViewController *aViewController = [[StartMenuViewController alloc] init];
self.myViewController = aViewController;
[aViewController release];
UIView *controllersView = [myViewController view];
window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];
[window setBackgroundColor:[UIColor redColor]];
[window addSubview:controllersView];
[window makeKeyAndVisible];
}
The view controller:
- (id)init {
if (self = [super init]) {
self.title = #"Start Menu";
}
return self;
}
// Implement loadView to create a view hierarchy programmatically, without using a nib.
- (void)loadView {
UIView *startView = [[UIView alloc] initWithFrame:[UIScreen mainScreen].applicationFrame];
[startView setAutoresizingMask:UIViewAutoresizingFlexibleHeight|UIViewAutoresizingFlexibleWidth];
[startView setBackgroundColor:[UIColor greenColor]];
self.view = startView;
[startView release];
}
Thanks for the help in advance!
Are you sure that you're inheriting from UIViewController and not overriding the implementation of - (UIView*)view?
EDIT: More info:
UIViewController has a special implementation of the "-(UIView*) view" message so that when it's called, the loadView method is called if the view member variable is not set. So, if you provide an implementation of "- (id)view" in your subclass, (or a property named view) it will break the auto-calling of "- loadView".
Just to document a "loadView is not called" case:
I wrote a 2 UITableViewController(s) to handle detail data for a master ViewController. Since the devil was in #2, I made a simple UITableViewController for #1, and referenced it in the XIB for the "master" ViewController.
When I was done with #2, I could simply copy the code to #1, remove the complicated code, and go on with life.
But to my dismay and several days work, no matter what I did, viewLoad was not being called for my simple #1 UITableViewController.
Today I finally realised that I was referencing the UITableViewController in the XIB to the master ViewController program. - and of course, loadView was never being called.
Just to help some other dork that makes the same mistake....
Best Regards,
Charles
viewDidLoad only if the view is unarchived from a nib, method is invoked after view is set.
loadView only invoked when the view proberty is nil. use when creating views programmatically. default: create a UIView object with no subviews.
(void)loadView {
UIView *view = [[UIView alloc] initWithFrame:[UIScreen
mainScreen].applicationFrame];
[view setBackgroundColor:_color];
self.view = view;
[view release];
}
By implementing the loadView method, you hook into the default memory management behavior. If memory is low, a view controller may receive the didReceiveMemoryWarning message. The default implementation checks to see if the view is in use. If its view is not in the view hierarchy and the view controller implements the loadView method, its view is released. Later when the view is needed, the loadView method is invoked
again to create the view.
I would strongly recommend you use interface builder for at least your initial Window/View.
If you create a new project in XCode you should be able to select from one of many pre-defined iPhone templates that come with everything setup.
Unless I am reading this wrong, you did not associate any view with the the controller's view property like this
myViewController.view = controllersView;
So as far as Cocoa is concerned the view you are setting in the window has no controller to call loadView on. loadView is a View controller, not view, method. The view you assign to the window is not associated with any view controller. So your view controller loadView method is never called. Get it? The view you are trying to display, has no view controller associated with it.
When you use interface builder to create views you can link the UIView object you created in IB to the view property in the controller in IB which the framework automatically
But if not done in IB you have to set it