UIImage 未添加到 UICollectionView 中的所有单元格

Question

I have added a collection view and added an image view for each cell. I was able to add and scale the image views for each cell, but they were slightly off centre. I set the image view's centre to the cell's centre, but this caused only one image to now show.

Here is the code:

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "CarCell", for: indexPath)
    
    let carImageView = UIImageView(image: UIImage(systemName: "car"))
    carImageView.frame = cell.contentView.frame
    carImageView.center = cell.center
    carImageView.contentMode = .scaleAspectFit
    cell.addSubview(carImageView)
    
    return cell
    
}

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
    
    let columns: CGFloat = 2
    
    let collectionViewWidth = collectionView.bounds.width
    let flowLayout = collectionViewLayout as! UICollectionViewFlowLayout
    let spaceBetweenCells = flowLayout.minimumInteritemSpacing * (columns - 1)
    
    let adjustedWidth = collectionViewWidth - spaceBetweenCells
    
    let width: CGFloat = floor(adjustedWidth / columns)
    let height: CGFloat = width
    
    return CGSize(width: width, height: height)
    
}

Here is the outcome:

And the view hierarchy shows all cells are created with their UIViews , but not the image views :

Removing the line carImageView.center = cell.center makes all images reappear again, but off-centre. Does anyone know how to fix this?

Answer 1

Can you try with the following?

let carImageView = UIImageView(image: UIImage(systemName: "car"))
carImageView.frame = cell.contentView.bounds
carImageView.center = CGPoint(x: cell.bounds.width/2, y: cell.bounds.height/2)
carImageView.contentMode = .scaleAspectFit
cell.addSubview(carImageView)