This is hard to explain so bear with me ... I'm using an example that I know works. It's the MapMe chapter from the Apress More iPhone dev book.
I'm using the same code but I've created a MapViewController class to contain all the map code and am inserting the view from the nib as a subview of my MainViewController view. With me?
My problem seems to be this : now the view containing the MKMapView object is a subview of the MainViewController it doesn't want to add the annotation object into the view. I can change the mapType and can initiate the locationManager:didUpdateToLocation to pinpoint my location. Indeed it drops the default red pin for me. My custom annotation object is not passed though.
Remember, this code worked fine when run directly from the MapViewController. It only breaks when I insert the view as a subview of another ViewController.
Ok, I'm an idiot ... the delegate wasn't set in the NIB ... DOH!!! Schoolboy error. Lesson learned.
Related
I have an application where small number of objects are defined in the MainWindow. A pair of these objects are a UIViewController and the UIImageView that goes along with this controller. When the application starts up, the entire MainWindow.xib get loaded & I can see that this UIImageView has been loaded into memory. At this point, I have no need for this UIImageView.
When I need the UIViewController, I perform the usual alloc/init setup. At this point, when I look at this controller with the debugger, the controller is setup correctly, but the UIImageView that should have been pre-wired with Interface Builder is always nil.
Any suggegstions on how to make sure this UIImageView is loaded into memory correctly? This is the only case where I've had an issue with objects defined within this single MainWindow.xib file.
Assuming you have connected the view outlet, all you need to do is access the view property. When you look in the debugger, you're seeing the property's corresponding ivar. When you access the property in code, it should load for you. So, it should be as simple as:
[controller view];
Not quite sure I understand the problem, but instead of having the UIImageView in MainWindow.xib, why not have it in the xxxViewController.xib where it's actually going to be needed?
I have a UITableViewController, nib based, that is presented in a UIPopoverController when running on iPad and presented 'natively' when running on iPhone.
When running on the iPad, the self.tableView property of the controller is nil throughout it's lifecycle. The delegate messages that pass in the tableView as part of their normal operation work fine and have a reference to a table view.
On the iPhone, the property is set and the reference is valid as you would expect.
Anything specific that can cause the self.tableView property to be nil? I've double checked the connections in Interface Builder - the Nib just contains a table view and the related UISearchBar stuff. The table view in the Nib is set as the view controller's view.
This is on 4.2.1 on both devices. Banging my head on this and can't find my error.
I figured out my problem and of course, it's a programming error.
In this case, an errant #synthesize tableView at the top of the implementation file, generating conflicting getters and setters.
Apologies and thanks for those that looked at this.
Try this... in one of the methods that returns the tableView object do "assert(self.view == tableView);" and see what happens. If the assert doesn't fire, and I suspect that it wont fire in either the iPhone or iPad, then simply cast self.view into a UITableView and do what you need to do.
My understanding about passing data back to a delegate completely revolves around making a new view controller and having it conform to a protocol.
I am trying to get a time input back from a UIDatePicker set with the UIDatePickerModeCountDownTimer mode and I am running into issues.
Inside of Main1.m I create a UIActionSheet *action, and set everything up so that it presents itself with a UIDatePicker on a click. Inside of Main.m I also say:
main.delegate = self;
If this were not a UIActionSheet, I would make a protocol reference inside the new ViewController and then have the new vc pass data to a method that Main has, but I can't do that with a UIActionSheet!!
What am I missing? I assume there is something inherently different about Action Sheets, ut I can't figure it out.
Thanks for your help!!!
EDIT:
Sorry! I was giving a generic name to my view controller. It isn't actually Main.m, its FirstViewController.h/m
I didn't realize that my generic reference was getting mixed up with the Main.m file that is completely different than a vc.
I don't exactly understand why you're putting your delegate assignment in Main.m. I assume that you're setting up your UIActionSheet in a ViewController, and launching it from there. In this case, your ViewController is your delegate object. So you need to make sure that your ViewController implements the UIActionSheetDelegate. ie:
#interface SomeController : UIViewController <UIActionSheetDelegate>
Then you simply implement the required methods of that delegate in your view controller class, and that should do it. If I'm missing something about how you're implementing this, then you need to provide more code examples to examine.
I found an example of a paging UIScrollView in Apple's developer docs and it's just what I want for my application. I have a main view with a "Help" button that I want to present a view that users can page through to see all the help topics. The sample is at:
https://developer.apple.com/library/ios/#documentation/WindowsViews/Conceptual/UIScrollView_pg/ScrollViewPagingMode/ScrollViewPagingMode.html%23//apple_ref/doc/uid/TP40008179-CH3-SW1
And it works as advertised, but, as with so many of Apple's examples, they do all kinds of code right in the AppDelegate. I have my own AppDelegate, but then I have a NavigationController with a RootView that has this "Help" button on it. I can't seem to get the example code integrated into my own and have it work. I'm pretty sure I can't put the code they have in their AppDelegate in my own, but how to set it up eludes me.
Can someone point me to an example where they do what I'm talking about?
EDIT: I was able to create a new project and get it to work like Apple's by moving all the AppDelegate methods into the UIViewController that the template supplied and creating a new ContentPage UIViewController to hold the content. It can scroll from page to page, so I think I can insert this code into my other project ok.
I replaced the applicationDidFinishLaunching with an equivalent viewDidLoad and got rid of the AppDelegate stuff dealing with window and such. Then I changed Apple's initWithPageNumber: method to refer to my help pages rather than just creating instances of their generic views.
- (id)initWithPageNumber:(int)page {
NSLog(#"--initWithPageNumber:ContentPage");
if (self = [super initWithNibName:[NSString stringWithFormat:#"HelpPage%d", page] bundle:nil]) {
pageNumber = page;
}
return self;
}
Thanks for the help - sometimes it's good just to have someone tell you it can be done to keep going!
In the sample code, the applicationDidFinishLaunching: method sets up the UIScrollView (and a UIPageControl, but let's ignore that for now) and then "loads" the first two pages. "Loading" a page consists of loading that page's view controller into memory and caching it. It then adds that controller's view as a subview to the UIScrollView offset with an appropriate x based on what "page number" it is. You should be able to do all that in your viewDidLoad.
If you have a blank view when your view controller's view is shown, then you haven't added the subview correctly to your UIScrollView. Depending on what exactly you changed, that could be some combination of (a) not getting the x offset correct, (b) not setting the frame correctly, or (c) not adding it as a subview correctly.
If you post some of your own code we might be able to shed some light on the problem.
I have been having huge issues with this, so I drew a diagram...
alt text http://tomsfil.es/7bdead0a.png
I successfully get to the CLASS A - METHOD B but at that point, IBOutlet Z is Nil? :(
Any ideas?
note
Somebody told me it might be an Overrelease and to use NSZombieEnabled but that confused me
It's all a matter of when you call the class. Right after you create a view controller with initWithNibName, nothing is actually wired up yet - it's only after the view is created that IBOutlets are created and wired in.
One trick is that you can simply ask the view controller for .view, like so:
myViewController.view;
Then the view will be created and the IBOutlet will exist. A better method though, is to create properties on the view controller that you set, and then either in viewDidLoad, or in viewWillAppear you use those properties to set values for your outlets.