如何在一个视图 controller 中创建具有相同行为的多个集合视图？

Question

我正在制作一个应用程序，用户可以在其中上传不同类型服装的照片并将其显示在收藏视图中。 用户可以从下拉菜单中单击一个按钮来告诉程序图像应该放在哪个部分下。 我本来只需要一个集合视图。 但现在我决定扩展到多个，但我只有一个代码。 有没有一种好方法来调整我已经编写的代码，以便其他集合视图具有与第一个相同的行为？

//
//  ViewController.swift
//  ugh as if
//
//

import UIKit
import PhotosUI
import Photos
import CoreData
import Foundation
import SwiftUI

// user images below
var imageIDs = [String]()
var countImage = Int()
var currentImageType = String()

class ViewController: UIViewController, PHPickerViewControllerDelegate {

    // when trash is pressed in ClsoetDetailViewController, return to ViewController
    @IBAction func unwindToCloset(segue: UIStoryboardSegue) {
        self.collectionView.reloadData()
    }
    
    
    @IBOutlet var collectionView: UICollectionView!
    @IBOutlet var outerwearCollectionView: UICollectionView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
    
        
        // popup menu items
        let tops = UIAction(title: "tops") { (action) in
              print("tops!")
            self.addPhotos(categoryType: "tops")
         }
         let outerwear = UIAction(title: "outerwear") { (action) in
             print("outerwear!")
             self.addPhotos(categoryType: "outerwear")
         }
         let bottoms = UIAction(title: "bottoms") { (action) in
              print("bottoms!")
             self.addPhotos(categoryType: "bottoms")
         }
        let singles = UIAction(title: "one pieces") { (action) in
             print("singles!")
            self.addPhotos(categoryType: "singles")
        }
        let accessories = UIAction(title: "accessories") { (action) in
             print("accessories!")
            self.addPhotos(categoryType: "accessories")
        }
        let shoes = UIAction(title: "shoes") { (action) in
             print("shoes!")
            self.addPhotos(categoryType: "shoes")
        }
        let menu = UIMenu(title: "my closet", options: .displayInline,
                           children: [tops , outerwear , bottoms, singles, shoes, accessories])
        
        // set up collection in closet
        // navigationItem.rightBarButtonItem = UIBarButtonItem(barButtonSystemItem: .add, target: self, action: #selector(addPhotos))
        navigationItem.rightBarButtonItems = [UIBarButtonItem(systemItem: .add, menu: menu)]
        
        collectionView.register(ClosetCollectionViewCell.nib(), forCellWithReuseIdentifier: "ClosetCollectionViewCell")
        
        // layout.minimumInteritemSpacing = 0
        
        let layout = UICollectionViewFlowLayout()
        layout.itemSize = CGSize(width: 75, height: 100)
        layout.minimumLineSpacing = 15
        
        collectionView.collectionViewLayout = layout
        
        collectionView.delegate = self
        collectionView.dataSource = self
    
        collectionView.reloadData()
    }
    
    
    // access photo library
    @objc private func addPhotos(categoryType: String) {
        var config = PHPickerConfiguration()
        config.selectionLimit = 100
        config.filter = .images
        let vc = PHPickerViewController(configuration: config)
        vc.delegate = self
        present(vc, animated: true)
        currentImageType = categoryType
    }
    
    func picker(_ picker: PHPickerViewController, didFinishPicking results: [PHPickerResult]) {
        picker.dismiss(animated: true, completion: nil)
        let group = DispatchGroup()
        results.forEach { result in
            group.enter()
            result.itemProvider.loadObject(ofClass: UIImage.self) { reading, error in
                defer {
                    group.leave()
                }
                guard let image = reading as? UIImage, error == nil else {
                    return
                }
                
                countImage += 1
                print(countImage)
                
                imageIDs.append(String(countImage))
                print(imageIDs)
                
                LocalFileManager.instance.saveImage(image: image, imageName: String(countImage), folderName: currentImageType)
            }
        }
        group.notify(queue: .main) {
            self.collectionView.reloadData()
        }
    }

}

extension ViewController: UICollectionViewDelegate {
func collectionView(\_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
collectionView.deselectItem(at: indexPath, animated: true)
print("you tapped me!")
// set closetImageName in ClosetDetailViewController
detailImageName = imageIDs\[indexPath.row\]

        print(imageIDs[indexPath.row])
        performSegue(withIdentifier: "closetDetail", sender: nil)
    }

}

extension ViewController: UICollectionViewDataSource {

    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        // how many cells are shown? based on number of items the user uploaded
        return countImage
    }
    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        // return cell for given item
            let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "ClosetCollectionViewCell", for: indexPath) as! ClosetCollectionViewCell
        // show every cell in image array
        cell.imageView.image = LocalFileManager.instance.getImage(imageName: imageIDs[indexPath.row], folderName: "tops")
        return cell
    }

}

extension ViewController: UICollectionViewDelegateFlowLayout {
// margin of padding between cells
func collectionView(\_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -\> CGSize {
return CGSize(width: 75, height: 100)
}

}

下面是集合视图的样子，但根据我现在的情况，所有照片只会发送到“tops”集合

我对 Xcode 还是很陌生，并且只使用了几个月，所以非常感谢您的帮助！

我尝试复制和编辑扩展中的功能（位于选择器下方），以便我能够将不同的照片发送到不同的位置，但它一直向我抛出错误。

extension ViewController: UICollectionViewDataSource {

    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        // how many cells are shown? based on number of items the user uploaded
        return countImage
    }
    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        // return cell for given item
        if collectionView == self.collectionView {
            let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "ClosetCollectionViewCell", for: indexPath) as! ClosetCollectionViewCell
            // show every cell in image array
            cell.imageView.image = LocalFileManager.instance.getImage(imageName: imageIDs[indexPath.row], folderName: "tops")
            return cell
        }
        else {
            let cell = outerwearCollectionView.dequeueReusableCell(withReuseIdentifier: "ClosetCollectionViewCell", for: indexPath) as! ClosetCollectionViewCell
            cell.imageView.image = LocalFileManager.instance.getImage(imageName: imageIDs[indexPath.row], folderName: "outerwear")
            return cell
        }
    }
}

Answer 1

您当前的集合视图仅使用 1 个部分。 您可以使用您拥有的集合视图中的多个部分，而不是添加多个集合视图。 您只需要将数据源从数组组织为 arrays 的数组。

您需要调整细节，但假设您的数据变为：

var images = [[UIImage]]() // Or an array of array of image ids

然后你的集合视图方法变成这样：

func numberOfSections(in collectionView: UICollectionView) -> Int {
    return images.count
}

func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
    return images[section].count
}

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    let cell = ... // however you get a cell
    cell.imageView.image = images[indexPath.section][indexPath.item]

    return cell
}

对其他方法进行一般模式。

如果需要显示类别标题或其他内容，您可以使用节标题设置集合视图。

如果所有功能基本相同，这比添加多个集合视图要简单得多。