I used a presentModalViewController to present a view and then after I try remove a UView using removeFromSuperview, but its not working anymore.
Before I used the command presentModalViewController , there's no problem in removing a Uiview from superview.
What changed?
First, presentModalViewController is deprecated so you should not be using it.
Per the UIViewController class reference, you should be using presentViewController:animated:completion: instead.
Secondly, if you use any of the present??ViewController methods, in order to dismiss it, you should use the appropriate dismiss??ViewController like this:
// Present the view controller
[self presentViewController:viewController animated:YES completion:NULL];
// Later, to dismiss it:
[self dismissViewControllerAnimated:YES completion:NULL];
Related
I've got plenty of experience with iOS, but Cocoa has me a bit confused. I read through several Apple docs on Cocoa but there are still details that I could not find anywhere. It seems the documentation was written before the NSDocument-based Xcode template was updated to use NSViewController, so I am not clear on how exactly I should organize my application. The template creates a storyboard with an NSWindow, NSViewController.
My understanding is that I should probably subclass NSWindowController or NSWindow to have a reference to my model object, and set that in makeWindowControllers(). But if I'd like to make use of the NSViewController instead of just putting everything in the window, I would also need to access my model there somehow too. I notice there is something called a representedObject in my view controller which seems like it's meant to hold some model object (to then be cast), but it's always nil. How does this get set?
I'm finding it hard to properly formulate this question, but I guess what I'm asking is:how do I properly use NSViewController in my document-based application?
PS: I understand that NSWindowController is generally meant to managing multiple windows that act on one document, so presumably if I only need one window then I don't need an NSWindowController. However, requirements might change and having using NSWindowController may be better in the long run, right?
I haven't dived into storyboards but here is how it works:
If your app has to support 10.9 and lower create custom of subclass NSWindowController
Put code like this into NSDocument subclass
- (void)makeWindowControllers
{
CustomWindowController *controller = [[CustomWindowController alloc] init];
[self addWindowController:controller];
}
If your app has multiple windows than add them here or somewhere else (loaded on demand) but do not forget to add it to array of document windowscontroller (addWindowController:)
If you create them but you don't want to show all the windows then override
- (void)showWindows
{
[controller showWindow:nil]
}
You can anytime access you model in your window controller
- (CustomDocument *)document
{
return [self document];
}
Use bindings in your window controller (windowcontroller subclass + document in the keypath which is a property of window controller)
[self.textView bind:#"editable"
toObject:self withKeyPath:#"document.readOnly"
options:#{NSValueTransformerNameBindingOption : NSNegateBooleanTransformerName}];
In contrast to iOS most of the views are on screen so you have to rely on patterns: Delegation, Notification, Events (responder chain) and of course MVC.
10.10 Yosemite Changes:
NSViewController starting from 10.10 is automatically added to responder chain (generally target of the action is unknown | NSApp sendAction:to:from:)
and all the delegates such as viewDidLoad... familiar from iOS are finally implemented. This means that I don't see big benefit of subclassing NSWindowCotroller anymore.
NSDocument subclass is mandatory and NSViewController is sufficient.
You can anytime access you data in your view controller
- (CustomDocument *)document
{
return (CustomDocument *)[[NSDocumentController sharedDocumentController] documentForWindow:[[self view] window]];
//doesn't work if you do template approach
//NSWindowController *controller = [[[self view] window] windowController];
//CustomDocument *document = [controller document];
}
If you do like this (conforming to KVC/KVO) you can do binding as written above.
Tips:
Correctly implement UNDO for your model objects in Document e.g. or shamefully call updateChangeCount:
[[self.undoManager prepareWithInvocationTarget:self] deleteRowsAtIndexes:insertedIndexes];
Do not put code related to views/windows into your Document
Split your app into multiple NSViewControllers e.g.
- (void)prepareForSegue:(NSStoryboardSegue *)segue sender:(id)sender {
if ([segue.identifier isEqualToString:AAPLListWindowControllerShowAddItemViewControllerSegueIdentifier]) {
AAPLListViewController *listViewController = (AAPLListViewController *)self.window.contentViewController;
AAPLAddItemViewController *addItemViewController = segue.destinationController;
addItemViewController.delegate = listViewController;
}
}
Previous code is called on windowcontroller with viewcontroller as delegate (again possible only after 10.10)
I always prefer to use multiple XIBs rather than one giant storyboard/XIB. Use following subclass of NSViewController and always inherit from it:
#import <Cocoa/Cocoa.h>
#interface MyViewController : NSViewController
#property(strong) IBOutlet NSView *viewToSubstitute;
#end
#import "MyViewController.h"
#interface MyViewController ()
#end
#implementation MyViewController
- (void)awakeFromNib
{
NSView *view = [self viewToSubstitute];
if (view) {
[self setViewToSubstitute:nil];
[[self view] setFrame:[view frame]];
[[self view] setAutoresizingMask:[view autoresizingMask]];
[[view superview] replaceSubview:view with:[self view]];
}
}
#end
Add a subclass of MyViewController to the project with XIB. Rename the XIB
Add NSViewController Object to the XIB and change its subclass name
Change the loading XIB name to name from step 1
Link view to substitute to the view you want to replace
Check example project Example Multi XIB project
Inspire yourself by shapeart or lister or TextEdit
And a real guide is to use Hopper and see how other apps are done.
PS: You can add your views/viewcontroller into responder chain manually.
PS2: If you are beginner don't over-architect. Be happy with the fact that your app works.
I'm relatively new to this myself but hopefully I can add a little insight.
You can use the view controllers much as you would in ios. You can set outlets and targets and such. For NSDocument-based apps you can use a view controller or the window controller but I think for most applications you'll end up using both with most of the logic being in the view controller. Put the logic wherever it makes the most sense. For example, if your nsdocument can have multiple window types then use the view controller for logic specific to each type and the window controller for logic that applies to all the types.
The representedObject property is primarily associated with Cocoa bindings. While I am beginning to become familiar with bindings I don't have enough background to go into detail here. But a search through the bindings programming guide might be helpful. In general bindings can take the place of a lot of data source code you would need to write on ios. When it works it's magical. When it doesn't work it's like debugging magic. It can be a challenge to see where things went wrong.
Let me add a simple copy-pastable sample for the short answer category;
In your NSDocument subclass, send self to the represented object of your view controller when you are called to makeWindowControllers:
- (void) makeWindowControllers
{
NSStoryboard* storyboard = [NSStoryboard storyboardWithName: #"My Story Board" bundle: nil];
NSWindowController* windowController = [storyboard instantiateControllerWithIdentifier: #"My Document Window Controller"];
MyViewController* myController = (id) windowController.contentViewController;
[self addWindowController: windowController];
myController.representedObject = self;
}
In you MyViewController subclass of NSViewController, overwrite setRepresentedObject to trap it's value, send it to super and then make a call to refresh your view:
- (void) setRepresentedObject: (id) representedObject
{
super.representedObject = representedObject;
[self myUpdateWindowUIFromContent];
}
Merci, bonsoir, you're done.
i have a navigationcontroller with some viewcontrollers and i need to know
how i can trigger the back-button-action on the navigationBar of each viewcontroller.
i have an allert-view and when user presses ok on this alert-view i want the
navigationcontroller to get one step back so i need to trigger the back-button
which appears on each navigationbar on the left side.
Does somebody knows how this works :)
Because if it doenst works i have to implement a navigationcontroller under each viewcontroller to make
[self dismissViewController animated:YES completion:nil]
and i dont want to do that.
You have to pop the front most view controller from the stack.
[self.navigationController popViewControllerAnimated:YES];
You could also use
[self.navigationController popToViewController:someViewController animated:YES];
if you wanted to go directly back to someViewController.
I am having a really weird issue when testing on my 1st gen. iPad (running iOS 5).
I have a UIView that I use as a property (with retain). I nil the property in the parent view's dealloc method. Pretty basic stuff. It works perfect on my iPad 3 running iOS 6, but doesn't get released on my 1st gen.
Any ideas what might be going on?
I'm not using ARC.
If you're retaining it, you have to release it. You can't just nil the instance variable.
So if you're property looks like this:
#property (nonatomic, retain) UIView *myView;
You're dealloc would either look like this:
- (void)dealloc
{
[myView release], myView = nil;
[super dealloc];
}
Or this:
- (void)dealloc
{
[self setMyView:nil];
[super dealloc];
}
Or this:
- (void)dealloc
{
self.myView = nil;
[super dealloc];
}
And your property will properly get released--unless something else is retaining it.
So I figured this out. It seems to be a bug in the iOS 6 SDK or maybe I just don't understand it. I have a UIViewController that presents another vc via presentViewController:animated:completion: —If I dismiss the presented vc then it releases and subsequently all subviews are removed and all is well.
However, if while the presented vc is showing, I remove/destroy the parent vc, the presented vc is deallocated but, its subviews are not told to removeFromSuperview; This doesn't show up as a leak in instruments, BUT it does prevent the subviews from deallocating.
This does not happen on iOS 6, thus I suspect this is a bug in iOS 5. Everything releases/deallocates as one would expect on iOS 6.
If someone has an explanation, or a better understanding of this, I would love to reward the answer to them instead of myself.
A view controller isn't responsible for removing its view from the superview when the view controller is dealloc'ed. The view controller is just responsible for releasing its own reference to it.
For example: you can create a view controller, ask for its view, then add that view to another view and throw away the view controller. In that case, you're just using the view controller as a view builder.
I'm not sure why the behavior is different in iOS 6, but would love to know.
If I already have a UIViewController(no nib) on iphone,and I wanna use it on ipad.
I use a IBOutlet(UIView)on ipad to show this view.
I try to set in viewDidLoad :
MacroMainView *marcoview =[[MacroMainView alloc]initWithNibName:nil bundle:nil];
marcoView =[marcoview view];
[[self view]addSubview:marcoView];
but still no work..
What should I do??
Thanks in advance.
You should use loadView method for a UIViewController without a nib. UIViewController Doc
If you create your views manually, you must override this method and use it to create your views
My Application have navigation controller and table views. When the back button is clicked and the view is popped out from controller stack, i noticed that the table events are not executed (eg: cellForRowIndexPath). Is there anyway that these events are execueted when view is popped out.
This is the code i use for pushing the view into controller stack.
MyViewController *obj = [[MyViewController alloc] initWithNibName:#"MyViewController" bundle:nil];
[self.navigationController pushViewController:obj animated:YES];
[obj release];
Regards
Sandy
You can use the ViewWillAppear and ViewWillDisappear methods.
what you want to do is put a call to
[theTable reloadData];
which initiates all of the calls that you wanted.
This call should be placed where you want the table to reload - either on appear or disappear.
Good Luck !