CODEWITHSUNDEEP
iosswift
Twitter khuong291
Twitter khuong291

Reputation: 11702

How to delete multiple items in Collection View

I have 2 Collection Views like this:

enter image description here

The first one is the Collection View for Albums, the second one is the Collection View for photos in each Album.

The datas are from server. I want to move some photos from AlbumA to AlbumB.

I have tried like this:

if response != nil {
    // Update UI Move photo from AlbumA to AlbumB
    // Get all images from albumA
    var sourceImages: [UIImage] = []
    for i in 0..<self.checkSelectedImages[self.selectedAlbumIndex].count {
        if self.checkSelectedImages[self.selectedAlbumIndex][i] == false {
            let cell = self.imageCollectionView.cellForItemAtIndexPath(NSIndexPath(forRow: i, inSection: 0)) as! ODIProfileMovePhotoImageCell
            let sourceImage = cell.imageView.image
            self.imageCollectionView.deleteItemsAtIndexPaths([NSIndexPath(forRow: i, inSection: 0)])
            sourceImages.append(sourceImage!)
            self.imageCollectionView.reloadData()
        }
    }
    // Send those above images to AlBumB
    for i in 0..<sourceImages.count {
        self.imageCollectionView.insertItemsAtIndexPaths([NSIndexPath(forRow: i, inSection: 0)])
    }
    self.imageCollectionView.reloadData()
}

and numberOfItemsInSection:

func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
    if collectionView == self.albumCollectionView {
        return listData.count + 1
    }
    else if collectionView == self.imageCollectionView {
        if listData.count > 0 {
            if selectedAlbumIndex > 0 {
                return listData[selectedAlbumIndex - 1].photos.count
            } else {
                return thumbnailImagesFromPhotoLibrary.count
            }
        }
    }
    return thumbnailImagesFromPhotoLibrary.count
}

But it crashes at this line:

self.imageCollectionView.deleteItemsAtIndexPaths(indexPaths!)

It says:

Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Invalid update: invalid number of items in section 0. The number of items contained in an existing section after the update (14) must be equal to the number of items contained in that section before the update (14), plus or minus the number of items inserted or deleted from that section (0 inserted, 1 deleted) and plus or minus the number of items moved into or out of that section (0 moved in, 0 moved out).'

How to solve this problem?

Upvotes: 0

Views: 1074

Answers (1)

Eman Rezk
Eman Rezk

Reputation: 422

You should remove the elements from the array first, then delete from the UICollectionView.

If you use checkSelectedImages to calculate the number of sections or items in a section, remove the element from it first.

Upvotes: 5

Related Questions