UICollectionView布局在iPad上崩溃，但在iPhone上运行良好

Question

UICollection view layout crasing in ipad, but works fine iphone. Will we have to manage UICollection view layout for ipad differently than iphone?

My code :

-(void)reloadData {


    if(collectionData!= nil)
    {
        collectionData = nil;
    }

    [self.collectionView reloadData];

}

-(void)setCollectionView {

    if(self.collectionView == nil) {
            //        self.collectionView = (UICollectionView *)[self.view viewWithTag:_wallCollectionView_tag];
       self.collectionView.dataSource = self;
        self.collectionView.delegate = self;
        self.collectionView.userInteractionEnabled = YES;
    }

}

`enter code here`- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView
{printf("\n = %s",__FUNCTION__);

    return 1;
}
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{

    return [collectionData count];
}

- (CGSize)collectionView:(UICollectionView *)collectionView
                  layout:(UICollectionViewLayout*)collectionViewLayout
  sizeForItemAtIndexPath:(NSIndexPath *)indexPath {
    if ( [ [ UIScreen mainScreen ] bounds ].size.width > 320) {
        return CGSizeMake(118, 118);
    }
    return CGSizeMake(100, 100);
}

Answer 1

*** Terminating app due to uncaught exception 'NSRangeException', reason:     '*** -[__NSArrayM objectAtIndex:]: index 5 beyond bounds [0 .. 4]' ***

This clearly says, that you trying to access element, which is beyond array bounds. Check next:

1. You use same array for -numberOfItemsInSection method and for -cellForItemAtIndexPath method.
2. You don't mutating array (deleting\\adding elements) while collectionView is updating.
3. You accessing datasource array correctly: to retrieve last element of array, which have 5 elements, you should use key "4" - collectionData[4] or collectionData[[collectionData count] - 1].