Display just two columns, with multiple rows in a CollectionView using storyboard

Question

I want to display only two cells in a row, no matter what the iPhone screen size is. Like,

My storyboard contains a UICollectionView,connected by constraints.

The storyboard settings for the UICollectionView is,

Now, when I run this in 6, 5s or below, only one cell appears in a row. The code I'd used is,

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section{     return [categoryImages count]; } - (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{     homePageCells *cell = (homePageCells *)[collectionView dequeueReusableCellWithReuseIdentifier:@"cells" forIndexPath:indexPath];     cell.categoryName.text = [categoryNames objectAtIndex:indexPath.row];      return cell; } 

I tried detecting the screen size and assigning appropriate cell size programmatically using the code,

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath {     CGSize sizes;       CGSize result = [[UIScreen mainScreen] bounds].size;     NSLog(@"%f",result.height);     if(result.height == 480)     {         //Load 3.5 inch xib         sizes =CGSizeMake(170.f, 170.f);         NSLog(@"3gs");     }     else if(result.height == 568)     {         //Load 4 inch xib         sizes =CGSizeMake(130.f, 130.f);         NSLog(@"5s");      }     else if(result.height == 667.000000)     {         //Load 4.7 inch xib         sizes =CGSizeMake(160.f, 160.f);         NSLog(@"6");      }     else     {         NSLog(@"else");          sizes =CGSizeMake(170.f, 165.f);      }     return sizes; } 

But I also know that this isn't the right way, so please give me a right way to handle this.

Answer 1

You need not check the device size because we can use the collectionView width to calculate the width of the cell. Using the cell width you can calculate the height as per your need.

One more thing: You need to use UICollectionViewDelegateFlowLayout & confirm the delegate & implement method below

  func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {     let padding: CGFloat =  50    let collectionViewSize = collectionView.frame.size.width - padding     return CGSizeMake(collectionViewSize/2, collectionViewSize/2)     } 

Update: Swift 4.0

  func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {         let padding: CGFloat =  50         let collectionViewSize = collectionView.frame.size.width - padding                  return CGSize(width: collectionViewSize/2, height: collectionViewSize/2)     } 

Note: I have answered the question considering the cells are square sized

Addition Information: Please make sure you make estimated size none https://i.stack.imgur.com/B9kmU.png

Answer 2

Xcode 8: Swift 3

I know this is an older question, but I found a few issues with accepted answer.

I had to use UICollectionViewDelegateFlowLayout which is not CollectionViewFlowLayout

Then

In it 'Padding' is of type Int and when you try to subtract it from the variable collectionViewSize it throws an error because they are different types. Very easy to fix however.

I just added : CGFloat to the line

Finally, while there is probably a better way to do it, I had to match the padding by adjusting the collectionView leading and trailing constraints.

So all in all this is what my code ended up looking like

extension LandingPageViewController: UICollectionViewDelegateFlowLayout {    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {      let padding: CGFloat = 25     let collectionCellSize = collectionView.frame.size.width - padding    return CGSize(width: collectionCellSize/2, height: collectionCellSize/2)     }  }