UICollectionView Swift 中的自定义单元大小

Question

I want to get the following Layout by using the UICollectionView, what's the best approach to achieve this.

I have tried this approach but not getting desired outcome

func collectionView(_ collectionView: UICollectionView, layout 
collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: 
IndexPath) -> CGSize {
let totalWidth = collectionView.bounds.size.width
let totalHeight = collectionView.bounds.size.height
let heightOfView = totalHeight / 3
let numberOfCellsPerRow = 2
let dimensions = CGFloat(Int(totalWidth) / numberOfCellsPerRow)
if (indexPath.item == 0) {
    return CGSize(width: collectionView.bounds.size.width, height: heightOfView)
} else {
    return CGSize(width: dimensions / 2, height: heightOfView)
}
}

Answer 1

add UICollectionviewdelegateFlowlayout to ur class and use collectionView(_:layout:sizeForItemAt:) method... here u can return size of items depending on index path

Answer 2

you can set 2 sections like this:

func numberOfSections(in collectionView: UICollectionView) -> Int {
    return 2
}

func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
    if section == 0 {
        return 1
    }
    return 4
}

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: cellId, for: indexPath)
    cell.backgroundColor = .blue
    return cell
}

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
    if indexPath.section == 0 {
        return .init(width: view.frame.width - 16, height: 120)
    }
    return .init(width: view.frame.width / 2 - 32, height: 120)
}

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
    return 0
}

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat {
    return 0
}