ios - 如何在 UICollectionView 中加载更多对象

Question

我有一个 Collection View 和要加载的数据。我的目标是当 Collection View 加载时，它只加载前 5 个项目。当我滚动到 Collection View 底部时，它会加载更多 5 个项目，然后再次加载，直到加载所有数据。

// The data to load (It already have 20 item loaded from server)
static var productInfo: [ProductInfo] = []

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    guard let cell = collectionView.dequeueReusableCell(withReuseIdentifier: MainProductCell.reuseIdentifier, for: indexPath) as? MainProductCell else {
        fatalError("Expected `\(MainProductCell.self)` type for reuseIdentifier \(MainProductCell.reuseIdentifier). Check the configuration in Main.storyboard.")
    }
        // Set data for collection cell
        cell.modelId = String(ProductCollectionViewController.productInfo[indexPath.row].productId)
        cell.modelName = String(ProductCollectionViewController.productInfo[indexPath.row].name)
        cell.modelPrice = String(ProductCollectionViewController.productInfo[indexPath.row].price)
        cell.modelImage = ProductCollectionViewController.productInfo[indexPath.row].image
        cell.objectImageView.downloadedFrom(link: ProductCollectionViewController.productInfo[indexPath.row].image, contentMode: UIViewContentMode.scaleAspectFit)
        cell.modelLink = String(ProductCollectionViewController.productInfo[indexPath.row].remoteStorage)
    }

    return cell
}

func collectionView(_ collectionView: UICollectionView, willDisplay cell: UICollectionViewCell, forItemAt indexPath: IndexPath) {
    let lastItem = ProductCollectionViewController.productInfo.count - 1
    if indexPath.row == lastItem {
        loadMore()
    }
}

func loadMore() {
    print("load more...")
    //How to handle load more here?
}

如何处理loadMore()函数？谢谢。

Answer 1

直到一切顺利

  if indexPath.row == lastItem && !loading {
    loading = true
    loadMore()
}