I found this code to display a modal view:
- (void)add:(id)sender {
// Create the root view controller for the navigation controller
// The new view controller configures a Cancel and Done button for the
// navigation bar.
RecipeAddViewController *addController = [[RecipeAddViewController alloc]
initWithNibName:#"RecipeAddView" bundle:nil];
addController.delegate = self;
// Create the navigation controller and present it modally.
UINavigationController *navigationController = [[UINavigationController alloc]
initWithRootViewController:addController];
[self presentModalViewController:navigationController animated:YES];
// The navigation controller is now owned by the current view controller
// and the root view controller is owned by the navigation controller,
// so both objects should be released to prevent over-retention.
[navigationController release];
[addController release];
}
My question is how do I implement this code (I'm going to place it in a buttonPress method)
Do I need to define anything in my header file? The bit that confuses me is that apple on provides this and no header file so i cant tell if anything should be there?
The code refers to RecipieAddViewController what do I repleace this with, "UIViewController" ?
What do I put as the delegate in the headerfile ? do I need to set this up anywhere else ? like with a property?
Is there anything else I need to do once I have copid this code in my buttonPress method to make it work?
Thanks and sorry for all the questions.
My question is how do I implement this code (I'm going to place it in a buttonPress method)
Define the method as an IBAction like -(IBAction)add:(id)sender and in interface builder bind a button's touch up inside event to the view controller object's add: action outlet.
Do I need to define anything in my header file? The bit that confuses me is that apple on provides this and no header file so i cant tell if anything should be there?
Nope. All this stuff needs is UIKit.h You usually need to change your header to add methods, add instance variables, or include custom classes. You may need a #import RecipeAddViewController.h somewhere (in your header or your implementation file) in order to use that class, however. This is true for any custom class you write that you want to use in another file.
The code refers to RecipieAddViewController what do I repleace this with, "UIViewController"?
Replace that with the view controller class you want to push. UIViewController itself is rarely useful naked. It's made to subclassed. So you create a new class that inherits from UIViewController, import it's header, create and instance of it, and push it on the navigation controller.
Related
iOS 5 adds a nice feature allowing you to nest UIViewControllers. Using this pattern it was easy for me to create a custom alert view -- I created a semi-transparent view to darken the screen and a custom view with some widgets in it that I could interact with. I added the VC as a child of the VC in which I wanted it to display, then added its views as subviews and did a little animation to bring it on the screen.
Unfortunately, I need to support iOS 4.3. Can something like this be done, or do I have to manage my "alert" directly from the VC in which I want to display it?
MORE INFO
So if I create a custom view in a nib whose file owner is "TapView" and who has a child view that is a UIButton. I tie the UIButton action to a IBAction in TapView.
Now in my MainControllerView I simple add the TapView:
TapView *tapView = [[TapView alloc] init];
[[self view] addSubview:tapView];
I see my TapView, but I can't interact with the UIButton on it and can interact with a UIButton on the MainControllerView hidden behind it. For some reason I am not figuring out what I'm missing...
Not sure if this helps, but, in situations where I've needed more control over potential several controllers, I've implemented a pattern where I have a "master" controller object (doesn't need to be descendent from UIViewController), which implements a delegate protocol (declared separately in it's own file), and then have whatever other controllers I need to hook into declare an object of that type as a delegate, and the master can do whatever it needs to do in response to messages from the controllers with the delegate, at whatever point you need; in your case, that being displaying the alert and acting as it's delegate to handle the button selection. I find this approach to be very effective, simpler and usually cleaner. YMMV ;-)
Regd. your second query, where you are trying to create a custom view using nib. Don't change the FileOwner type, instead set "TapView" for the class property of the top level view object.
Once you have done this, you might experience difficulty when making connections. For that just manually choose the TapView file for making connections.
Also, to load the view you need to load its nib file. For which you can create a class level helper method in TapView class like below
+(TapView *) getInstance
{
NSArray *bundle = [[NSBundle mainBundle] loadNibNamed:#"TapView" owner:self options:nil];
TapView *view;
for (id object in bundle) {
if ([object isKindOfClass:[TapView class]]) {
view = (TapView *) object;
break;
}
}
return view;
}
Now, you get a refrence to you view object like this
TapView *tapView = [TapView getInstance];
Let's say I have a view controller called vc1, which a synthesized property called property1, and i wants to access it from another view controller (vc2) and change it from vc2.
Now the methods created by the #syntisize to change and get properties are instance methods, so how can I get to them fro another view controller (do view controllers have instances in the app, and if so, what are they?)
Just to be clear I am using storyboards, so I never really instantiate the view controllers...
VC1.m:
-(void) yourMethod {
...
}
VC2.m
YOURViewController * vc2 = [[YOURViewController alloc]init];
[vc yourMethod];
[vc release];
Make sure to import your YOURViewController in your other view .m file
Something like that should work.
Or if you're having problems, try this tutorial here:
Tutorial on How-To Pass Data Between Two View Controllers
Hope this helps :)
While you can do it the way you describe, I think the common technique (assuming VC1 has a segue to VC2) is a bit different, where VC2 will have a property that will be set by prepareForSegue. See Configuring the Destination Controller When a Segue is Triggered in the View Controller Programming Guide.
You will need to link the storyboard views with the viewcontrollers so the view for vc1 would use the class vc1 etc for the rest (I assume you have done this because this is important when coding for different views)
Then all you need to do is where ever you are calling the properties so lets say the viewDidLoad method, declare the view controller like this:
- (void) viewDidLoad {
vc1 *viewController;
// Now you change the variable I'll presume its a UILabel so I'll change its text [viewController.property1 setText:#"I changed a different views UILabel"];
}
Let me know whether this works... Its worked for me before so should work
I have a UIButton that I create in my sub class ViewController, and add it to my MainViewController.
Now, I added a target method to this button that should push another view controller to my Navigation controller (the one that in the MainViewController).
I know that the method did call when I push the button, but the view wasn't push to the Navigation Controller.
I scanned this drawing - this is the drawing (I also added part of my code):
This is the code I'm using in my button:
(remember it's in a deferent ViewController).
- (void)buttonPressed:(UIButton *)sender
{
Photo_ScreenGlobalView *photo = [[Photo_ScreenGlobalView alloc] init];
[self.navigationController pushViewController:photo animated:YES];
}
Usually I solve these situations with delegation. If there is a view controller which is subordinate to another (i.e. a "sub" view controller) but should have the ability to trigger navigation changes, etc... then it should have a weak pointer back to it's 'parent'. Then the parent VC should implement an appropriately named protocol with a callback for the child to use. The names of these things can be generic, such as #property navigationDelegate and requestNavigationToViewController: or they can be more semantic, such as #property userFormDelegate and userFormDoneButtonPressed:
Generally speaking, a subordinate view controller should not be able to directly modify navigation at it's parent's level; but it can trigger it via more loosely-coupoled interfaces like these.
i came back to let you all know how i actually did it.
after googling a lot found this nice and quick guide how to make DELEGATE
and working with delegate solved all my problems. if you need any help don't hesitate to send me PM.
this is the guide:
http://css.dzone.com/articles/do-not-publishcreating-your
I have a simple test app (in OSX) that has a view controller with a button in its view. The button's action method is in the view controller's class, and that IBAction is connected in IB (through File's Owner). When the button is clicked, I get an EXC_BAD_Access error (except occasionally I get -[NSRunLoop buttonClick:] instead). I've read a bunch of posts here on SO having to do with NSViewControllers not being in the responder chain, but also that specifically hooking the action method up in IB should work. The only code I have is this:
In the app delegate:
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
TestController *controller = [[TestController alloc] initWithNibName:#"TestController" bundle:nil];
[self.window.contentView addSubview:controller.view];
}
And, in the TestController class, just this:
-(IBAction)buttonClick:(id)sender {
NSLog(#"%#",sender);
}
I have 2 questions. Why is this happening, and where is the correct mvc place to put IBActions for button methods (shouldn't controller classes handle these)?
First off, I believe in the App Delegate there is already a property called viewController already defined for you. You should use this code self.viewController = [[TestController alloc] initWithNibName:#"TestController" bundle:nil]; instead of TestController *controller = [[TestController alloc] initWithNibName:#"TestController" bundle:nil];. If that doesn't fix it, then I'm not sure what's wrong. Your code should return the attributes of the button you clicked. I created my own sample project and tested out your code (although my app delegate looked different than yours) and it worked fine.
Second, you should elaborate on your second question "Why is this happening, and where is the correct mvc place to put IBActions for button methods (shouldn't controller classes handle these)?". It's not very clear what you mean.
Hope this helps a little.
NSViewController will not respond to IBActions on mac os x on iPhone It is the correct place to put your IBAction as the view should only draw its content (data) not change it. But on Mac os x the NSViewController is for setting up the NSView it's no ment to respond to IBActions you have two choices one is to put your IBAction in your NSView or is create a NSWindowController .
On mac osx you have plenty of screen space and you will alway have views within a window you'll use NSViewController to add them to your window and to setup your view but the window is first in your responder chain then your NSWindowController . eg: you may have one window and two view controller showing the same view which may have 5 test fields in it and view controller one loads that with data but you can not edit the data then view controller two loads the same view with the same data but enable editing for the text fields so. but all action methods will go to the WindowController .
I recommend you to check your viewController's identity inspector.
It may indicate wrong custom class.
viewController created basically usually has name ViewController on the section.
I might be confused here and asking the wrong question.
If I use a class like the UISplitViewController inside the appdelete.m, will the only message i will receive is the message the UISplitViewController calls and not any VIEW message? for example:
in my myappdelegate.m
....
UISplitViewController *mySplitViewController = [[UISplitViewController alloc] init];
mySplitViewController.viewControllers = [NSArray arrayWithObjects:leftside,rightside,nil];
...
mySplitViewController.delegate = self;
....
[windows addSubView:mySplitViewController.view];
....
-(void) viewWillAppear:(BOOL) animated {
}
in myappdelegate.h I included UISplitViewControllerDelegate
I expected viewWillAppear to fire but it is not. I assume if I had subclass UISplitViewControler it would have fire. right?
BTW: I am doing this without using IB. Do I need to set the target for the mySplitViewController?
What I want to do is setup the orientation of the splitviewcontroller when it rotates.
the viewWillAppear method and other view related methods will be called on the view or view controller themselves, not on the delegate.
That means that if you make a subclass of UISplitViewController called SplitViewControllerSubClass, the view... methods will be called on the instance of SplitViewControllerSubClass, not on the delegate object.
But considering you are creating the views and displaying them programmatically, you already know exactly when the view will appear (i.e., right before you add it to the window), so I believe you could do whatever setup you want at that point.