CODEWITHSUNDEEP
objective-cuicollectionviewcelluicollectionviewcell
j.TK
j.TK

Reputation: 223

collectionView cellForItemAtIndexPath: called twice

I have the following code:-

- (UICollectionViewCell *)collectionView:(UICollectionView       *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{// Dequeue a prototype cell and set the label to indicate the page
CustomCellCollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"SurveyCell" forIndexPath:indexPath];
currentQuestion = [finalQuestionArray objectAtIndex:indexPath.row];

return cell;

}

so on loading first cell, cellForItemAtIndexPath is called only once but on loading second cell cellForItemAtIndexPath is called twice and currentQuestion is updated with the question in third cell not with second cell. How can I solve this?

I have pagecontrol over the collection view. Here is the code for creating collection view and adding paging on it

-(void)createCollectionView{
UICollectionViewFlowLayout *flowLayout = [[UICollectionViewFlowLayout alloc] init];
flowLayout.scrollDirection = UICollectionViewScrollDirectionHorizontal;
flowLayout.minimumLineSpacing = 0;
flowLayout.minimumInteritemSpacing = 0;

// Set up the collection view with no scrollbars, paging enabled
// and the delegate and data source set to this view controller
self.collectionView = [[UICollectionView alloc] initWithFrame:self.view.frame collectionViewLayout:flowLayout];
self.collectionView.showsHorizontalScrollIndicator = YES;
self.collectionView.backgroundColor = [UIColor clearColor];
self.collectionView.pagingEnabled = YES;
self.collectionView.delegate = self;
self.collectionView.dataSource = self;
// Register a prototype cell class for the collection view
[self.collectionView registerNib:[UINib nibWithNibName:@"CustomCellCollectionViewCell" bundle:nil] forCellWithReuseIdentifier:@"SurveyCell"];

[self.view addSubview:self.collectionView];
[self createPaging];

}

-(void)createPaging{
// page control
CGFloat w = self.view.frame.size.width;
CGFloat h = self.view.frame.size.height;

// Set up the page control
CGRect frame = CGRectMake(0, h - 84, w, 60);
pageControl = [[UIPageControl alloc] initWithFrame:frame];

// Add a target that will be invoked when the page control is
// changed by tapping on it
[pageControl addTarget:self action:@selector(pageControlChanged:) forControlEvents:UIControlEventValueChanged];

// Set the number of pages to the number of pages in the paged interface
// and let the height flex so that it sits nicely in its frame
pageControl.numberOfPages = numberOfPages;
pageControl.pageIndicatorTintColor = [UIColor blueColor];
pageControl.currentPageIndicatorTintColor = [UIColor redColor];
pageControl.autoresizingMask = UIViewAutoresizingFlexibleHeight;
[self.view addSubview:pageControl];

}

Upvotes: 1

Views: 2445

Answers (2)

j.TK
j.TK

Reputation: 223

We should now expect some cells to be created (cellForItemAtIndexPath:) but never displayed in iOS 10. If for some wacky reason we didn't want this wonderful new behavior, we can set our collection view's isPrefetchingEnabled property to false (it defaults to true in iOS 10).

Hope this helps someone! :) you can refer below link [link]UICollectionView cellForItem called not correctly

Upvotes: 4

Luca Fritz Ferrari
Luca Fritz Ferrari

Reputation: 31

 -(UICollectionViewCell *) collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {


    CustomCellCollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"SurveyCell" forIndexPath:indexPath];


    for (int i = 0; i < finalQuestionArray.count; i++) {

                NSLog(@"index i %i", i);

                if (indexPath.item == i) {
                    currentQuestion = [finalQuestionArray objectAtIndex:i];


                 }
    }

    return cell;

}

Try this, maybe can solve your problem.

Upvotes: 1

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