Adding CollectionView programmatically - ios

Question

I'm attempting to add a CollectionView to my application with images. So I have setup one cell in the xib file and added an imageview, gave the cell identifier "Cell" for now and set it's delegate and datasource to the file's owner.
The issue I am having right now is that the application crashes whenever I enter the screen with that CollectionView.
2014-02-12 10:26:46.429 CollectionApp[509:a0b] *** Assertion failure in -[CollectionViewController loadView], /SourceCache/UIKit_Sim/UIKit-2903.23/UICollectionViewController.m:166
2014-02-12 10:26:46.510 CollectionApp[509:a0b] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: '-[UICollectionViewController loadView] loaded the "34q-Sl-gDP-view-cX9-PP-w1h" nib but didn't get a UICollectionView.'
*** First throw call stack:
(
0 CoreFoundation 0x0191b5e4 __exceptionPreprocess + 180
1 libobjc.A.dylib 0x0169e8b6 objc_exception_throw + 44
2 CoreFoundation 0x0191b448 +[NSException raise:format:arguments:] + 136
3 Foundation 0x0127efee -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] + 116
4 UIKit 0x008eaec3 -[UICollectionViewController loadView] + 582
5 UIKit 0x003c90ae -[UIViewController loadViewIfRequired] + 78
6 UIKit 0x003c95b4 -[UIViewController view] + 35
7 UIKit 0x004003ae -[UITabBarController transitionFromViewController:toViewController:transition:shouldSetSelected:] + 407
8 UIKit 0x003ffbd2 -[UITabBarController transitionFromViewController:toViewController:] + 63
9 UIKit 0x003fbfbb -[UITabBarController _setSelectedViewController:] + 279
10 UIKit 0x003fbe9c -[UITabBarController setSelectedViewController:] + 180
11 UIKit 0x003fface -[UITabBarController _tabBarItemClicked:] + 312
12 libobjc.A.dylib 0x016b0874 -[NSObject performSelector:withObject:withObject:] + 77
13 UIKit 0x002b70c2 -[UIApplication sendAction:to:from:forEvent:] + 108
14 UIKit 0x002b704e -[UIApplication sendAction:toTarget:fromSender:forEvent:] + 61
15 UIKit 0x00565659 -[UITabBar _sendAction:withEvent:] + 479
16 libobjc.A.dylib 0x016b081f -[NSObject performSelector:withObject:] + 70
17 UIKit 0x002b70c2 -[UIApplication sendAction:to:from:forEvent:] + 108
18 UIKit 0x002b704e -[UIApplication sendAction:toTarget:fromSender:forEvent:] + 61
19 UIKit 0x003af0c1 -[UIControl sendAction:to:forEvent:] + 66
20 UIKit 0x003af484 -[UIControl _sendActionsForEvents:withEvent:] + 577
21 UIKit 0x003af0f6 -[UIControl sendActionsForControlEvents:] + 48
22 UIKit 0x00569f80 -[UITabBar(Static) _buttonUp:] + 123
23 libobjc.A.dylib 0x016b0874 -[NSObject performSelector:withObject:withObject:] + 77
24 UIKit 0x002b70c2 -[UIApplication sendAction:to:from:forEvent:] + 108
25 UIKit 0x002b704e -[UIApplication sendAction:toTarget:fromSender:forEvent:] + 61
26 UIKit 0x003af0c1 -[UIControl sendAction:to:forEvent:] + 66
27 UIKit 0x003af484 -[UIControl _sendActionsForEvents:withEvent:] + 577
28 UIKit 0x003ae733 -[UIControl touchesEnded:withEvent:] + 641
29 UIKit 0x002f451d -[UIWindow _sendTouchesForEvent:] + 852
30 UIKit 0x002f5184 -[UIWindow sendEvent:] + 1232
31 UIKit 0x002c8e86 -[UIApplication sendEvent:] + 242
32 UIKit 0x002b318f _UIApplicationHandleEventQueue + 11421
33 CoreFoundation 0x018a483f __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 15
34 CoreFoundation 0x018a41cb __CFRunLoopDoSources0 + 235
35 CoreFoundation 0x018c129e __CFRunLoopRun + 910
36 CoreFoundation 0x018c0ac3 CFRunLoopRunSpecific + 467
37 CoreFoundation 0x018c08db CFRunLoopRunInMode + 123
38 GraphicsServices 0x0359c9e2 GSEventRunModal + 192
39 GraphicsServices 0x0359c809 GSEventRun + 104
40 UIKit 0x002b5d3b UIApplicationMain + 1225
41 CollectionApp 0x0000ed9d main + 141
42 libdyld.dylib 0x01f57725 start + 0
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb)
Here's my CollectionViewController.h
#import "CollectionViewController.h"
#interface CollectionViewController () {
NSArray * listImages;
}
#end
#implementation CollectionViewController
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
listImages = [NSArray arrayWithObjects:#"7513-kirjatkuivumassa.jpg", #"kuppi.jpg", #"kuva1.jpg", #"juna-042.jpg", #"rautio-valamonruusut-helleaamuna-maalaus.jpg", #"pysähtynyt1.jpg", #"Screen-Shot-2013-02-20-at-21.07.38.jpg", #"sateenkaari.jpg", #"Screen-Shot-2013-02-21-at-17.04.22.jpg", #"moninaiset-e1391026376696.jpg", #"Tomperi+Metsä20111.jpg", #"3-shinot.jpg", #"Ulpukat.jpg", #"janne-e1391025808211.jpg", #"martikainen-240x240.jpg", #"takala-240x240.jpg", #"paanukallokaarme1.jpg", #"käsityök-240x240.jpg", #"kuvis-004.jpg", #"Se-on-hieno-2012-tammi-105x28x223.jpg", nil];
}
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
return listImages.count;
}
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
static NSString *identifier = #"Cell";
UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:identifier forIndexPath:indexPath];
UIImageView *listImageView = (UIImageView *)[cell viewWithTag:100];
listImageView.image = [UIImage imageNamed:[listImages objectAtIndex:indexPath.row]];
return cell;
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
#end
Please note that I am a complete noob when it comes to coding with Objective C. I'm currently attempting to study it.

Answer 1

All I had to do was to change
#interface CollectionViewController : UICollectionViewController
To
#interface CollectionViewController : UIViewController
Now there's no errors and everything works as intended.

Answer 2

You need register your xib cell to your UICollectionView on -(void)viewDidLoad of your view Controller.
[_tableView registerNib:[UINib nibWithNibName:#"nibName"
bundle:nil]
forCellReuseIdentifier:#"cellIdentifer"];