Question

我正在使用表格视图来显示包含图像的项目标题。我正在使用FirebaseStorage和FirebaseDatabase。

问题是，当我只有一个保护时，我单击“标题”时会收到“致命错误：索引超出范围”。当我有多个项目时，您可以看到视频中发生的情况。

也许有人可以帮助我，因为索引处理有些不对劲。：）

import UIKit
import Kingfisher
import Foundation
import FirebaseStorage
import FirebaseDatabase

class HomeViewController: UIViewController  {

    // MARK: - Properties

    @IBOutlet weak var tableView: UITableView!
    @IBOutlet weak var addProject: UIButton!


    var posts = [Post]()



    var textToBeSent: String = ""
    override func viewDidLoad() {
        super.viewDidLoad()

        UserService.posts(for: User.current) { (posts) in
            self.posts = posts
            self.tableView.reloadData()
        }

        Utilities.addShadowtoButton(addProject)

    }

    func configureTableView() {
        // remove separators for empty cells
        tableView.tableFooterView = UIView()
        // remove separators from cells
        tableView.separatorStyle = .none
    }
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        if segue.identifier == "toDetails" {
            let destVC = segue.destination as! ShowProjectDetailsViewController
            destVC.post = sender as? Post
        }
    }

}
extension Collection where Indices.Iterator.Element == Index {
             public subscript(safe index: Index) -> Iterator.Element? {
               return (startIndex <= index && index < endIndex) ? self[index] : nil
             }
          }

// MARK: - UITableViewDataSource

extension HomeViewController: UITableViewDataSource {

    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        let post = posts[indexPath.row]
        performSegue(withIdentifier: "toDetails", sender: post)

    }

  func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
      return 2
  }

    func numberOfSections(in tableView: UITableView) -> Int {
        return posts.count
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let post = posts[indexPath.section]

        switch indexPath.row {
        case 0:

            let cell = tableView.dequeueReusableCell(withIdentifier: "PostImageCell") as! PostImageCell
            let imageURL = URL(string: post.imageURL)
            cell.postImageView.kf.setImage(with: imageURL)

            return cell

        case 1:

            let cell = tableView.dequeueReusableCell(withIdentifier: "PostSubCell") as! PostSubCell
            cell.projectName.text = post.projectTitle

            return cell


        default:
            fatalError("Error: unexpected indexPath.")
        }
    }

}

// MARK: - UITableViewDelegate

extension HomeViewController: UITableViewDelegate {

    func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
        switch indexPath.row {
        case 0:

           let post = posts[indexPath.section]
           return post.imageHeight

        case 1:

       return PostSubCell.height

        default:
            fatalError()
        }
    }
    }


import Foundation
import FirebaseAuth.FIRUser
import FirebaseDatabase
import FirebaseUI
import FirebaseAuth


struct UserService {

         static func posts(for user: User, completion: @escaping ([Post]) -> Void) {

            let ref = Database.database().reference().child("posts").child(user.uid)

            ref.observe(DataEventType.value, with: { (snapshot) in
               guard let snapshot = snapshot.children.allObjects as? [DataSnapshot] else {
                   return completion([])
            }

            let posts = snapshot.reversed().compactMap(Post.init)
            completion(posts)
        })
    }

}


import Foundation
import UIKit
import FirebaseDatabase.FIRDataSnapshot

class Post {

//      Next let's add properties to store all the additional information we need. Add the following to your post class.
    var key: String?

       let imageURL: String
       let imageHeight: CGFloat
       let creationDate: Date
       let imageName: String
       let projectTitle: String
       let projectLocation: String
       let projectDescription: String
       let projectBeginn: String
       let projectEnd: String


//    You'll get some compiler errors for not having any initializers or default values for certain properties. Let's go ahead and fix that:

    init(imageURL: String, imageName: String, imageHeight: CGFloat, projectTitle: String, projectLocation: String, projectDescription: String, projectBeginn: String, projectEnd: String) {
        self.imageURL = imageURL
        self.imageName = imageName
        self.imageHeight = imageHeight
        self.creationDate = Date()
        self.projectTitle = projectTitle
        self.projectLocation = projectLocation
        self.projectDescription = projectDescription
        self.projectBeginn = projectBeginn
        self.projectEnd = projectEnd
    }

    var dictValue: [String : Any] {
        let createdAgo = creationDate.timeIntervalSince1970

        return ["image_url" : imageURL,
                "image_name" : imageName,
                "image_height" : imageHeight,
                "created_at" : createdAgo,
                "projectTitle" : projectTitle,
                "projectLocation" : projectLocation,
                "projectDescription" : projectDescription,
                "projectBeginn" : projectBeginn,
                "projectEnd": projectEnd ]

    }
    init?(snapshot: DataSnapshot) {
        guard let dict = snapshot.value as? [String : Any],
            let imageURL = dict["image_url"] as? String,
            let imageName = dict["image_name"] as? String,
            let imageHeight = dict["image_height"] as? CGFloat,
            let createdAgo = dict["created_at"] as? TimeInterval,
            let projectTitle = dict["projectTitle"] as? String,
            let projectLocation = dict["projectLocation"] as? String,
            let projectDescription = dict["projectDescription"] as? String,
            let projectBeginn = dict["projectBeginn"] as? String,
            let projectEnd = dict["projectEnd"] as? String




            else { return nil }

        self.key = snapshot.key
        self.imageURL = imageURL
        self.imageName = imageName
        self.imageHeight = imageHeight
        self.creationDate = Date(timeIntervalSince1970: createdAgo)
        self.projectTitle = projectTitle
        self.projectLocation = projectLocation
        self.projectDescription = projectDescription
        self.projectBeginn = projectBeginn
        self.projectEnd = projectEnd

       }
  }

感谢您的帮助！

Answer 1

您由numberOfSection创建了[Post]。您还可以点击performSegue来分配indexPath.row。因此会引发错误，您必须在indexPath.section方法中使用indexPath.row而不是didSelectItem()

例如

 func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath)   
 {
     let post = posts[indexPath.section] // Use here section instead of row
     performSegue(withIdentifier: "toDetails", sender: post)

 }

Swift TableView ImageView + Label =致命错误：索引超出范围

1 个答案: