在Api请求中选择并传递多个图像Swift

Question

我是新手，我试图找出一种选择多个图像并将其作为API请求中的数组传递的方法。我尝试使用DKImagePickerController，其中我无法选择多个图像甚至预览它们，但是我不知道将它们作为数组传递给api。 代码如下：

import UIKit


class CameraTabViewController: UIViewController,UICollectionViewDataSource, UICollectionViewDelegate{



 override func viewDidLoad() {
        super.viewDidLoad()
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    @IBAction func saveCamBtn(_ sender: Any) {
        let parent = self.parent as! DiaryEntryViewController
        parent.CameraView.isHidden  = true
    }

    @IBAction func selectPhotoBtn(_ sender: Any) {
        let pickerController = DKImagePickerController()
        pickerController.defaultSelectedAssets = self.assets
        pickerController.didCancel = { ()
        }

        pickerController.didSelectAssets = { [unowned self] (assets: [DKAsset]) in
            self.updateAssets(assets: assets)
        }
        self.present(pickerController, animated: true)
    }
    var pickerController: DKImagePickerController!

    var assets: [DKAsset]?

    @IBOutlet var previewView: UICollectionView!
    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int{

        return self.assets?.count ?? 0
    }

    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {

        let asset = self.assets![indexPath.row]
        var cell: UICollectionViewCell?
        var imageView: UIImageView?
        if asset.isVideo {
            cell = collectionView.dequeueReusableCell(withReuseIdentifier: "CellVideo", for: indexPath)
            imageView = cell?.contentView.viewWithTag(1) as? UIImageView
        } else {
            cell = collectionView.dequeueReusableCell(withReuseIdentifier: "CellImage", for: indexPath)
            imageView = cell?.contentView.viewWithTag(1) as? UIImageView
        }

        if let cell = cell, let imageView = imageView {
            let layout = collectionView.collectionViewLayout as! UICollectionViewFlowLayout
            let tag = indexPath.row + 1
            cell.tag = tag
            asset.fetchImageWithSize(layout.itemSize.toPixel(), completeBlock: { image, info in
                if cell.tag == tag {
                    imageView.image = image
                }
            })
        }
        return cell!
    }

    func updateAssets(assets: [DKAsset]) {
        self.assets = assets
        self.previewView?.reloadData()
     }
 }