ios - 加载注释时解包可选值时出现意外 fatal error

Question

大家好，我已经被这个问题困扰了近两周了

问题是我在加载评论时解开可选值时意外收到 fatal error ..

我正在尝试加载 JSON 数据以供评论在PopularShotsCollectionViewController中

    import UIKit
    import FMMosaicLayout

    private let reuseIdentifier = "Cell"

    class PopularShotsCollectionViewController: UICollectionViewController {
        private var shots : [Shot] = [Shot](){
            didSet{
                self.collectionView?.reloadData()
            }
        }


        var API_URL = Config.SHOT_URL
        var shotPages = 1


        var shot : Shot!
        var comments : [Comment] = [Comment]()
        var tableView : UITableView!

        override func viewDidLoad() {
            super.viewDidLoad()


            let layout : FMMosaicLayout = FMMosaicLayout()
            self.collectionView?.collectionViewLayout = layout

            // Do any additional setup after loading the view.
            self.title = "Popular"
            self.API_URL = Config.POPULAR_URL
            self.loadShots()
            self.loadComments()

       }

        func loadComments(){
 //  When i debug shot.commentsUrl does not return nil
         DribbleObjectHandler.getComments(shot.commentsUrl) { (comments) -> Void in
            self.comments = comments
          }
        }

但我收到此错误:

getCommentsMethod 的代码

  class func getComments(commentsUrl : String, completion:(([Comment]) -> Void)) {
    var comments = [Comment]()
    let url = commentsUrl + "&access_token=" + Config.ACCESS_TOKEN

     HttpService.getJSON(url) { (jsonData) -> Void in

        for commentData in jsonData {
          let comment = Comment(data: commentData as! NSDictionary)
          comments.append(comment)
        }
         let priority = DISPATCH_QUEUE_PRIORITY_DEFAULT
         dispatch_async(dispatch_get_global_queue(priority, 0), { () -> Void in
            dispatch_async(dispatch_get_main_queue(), { () -> Void in
                completion(comments)
            })
         })
        }
    }

HttpService 的代码

import Foundation
import UIKit
import Alamofire

class HttpService {
    class func getJSON(url: String, callback:((NSArray) -> Void)) {
        let nsURL = NSURL(string: url)!
        Alamofire.request(.GET, nsURL).response { (request, response, data, error) -> Void in
            if error != nil{
                print("error")
            }

            if data != nil {
                let jsonData = (try! NSJSONSerialization.JSONObjectWithData(data!, options: NSJSONReadingOptions.MutableContainers)) as! NSArray
                print(jsonData)
                callback(jsonData)
            }
        }
    }
}

如果您需要更多代码来解决问题，我非常高兴

在PopularShotsCollectionViewController中我也一直在加载镜头用同样的方法

 func loadShots(){

      DribbleObjectHandler.getShots(API_URL) { (shots) -> Void in
        self.shots = shots
     }
}

但我没有收到任何错误并且它工作完美get Shots 的代码是相同的。只需我们访问 loadShots 中的 Shot 类，然后访问 loadComments 中的 Comment 类

评论类

import Foundation
import UIKit

class Comment {

    var id : Int!
    var body : String!
    var date : String!

    var user : User!

    init(data : NSDictionary){

        self.id = data["id"] as! Int
        let bodyHTML = Utils.getStringFromJSON(data, key: "body")
        self.body = Utils.stripHTML(bodyHTML)

        let dateInfo = Utils.getStringFromJSON(data, key: "created_at")
        self.date = Utils.formatDate(dateInfo)

        if let userData = data["user"] as? NSDictionary {
            self.user = User(data: userData)
        }
    }
}

射击类代码

import Foundation

    class Shot: DribbbleBase {

        var imageUrl : String!
        var htmlUrl : String!
        var commentsUrl : String!
        var bucketsUrl : String!
        var likesUrl : String!
        var attachmentUrl : String!
        var reboundUrl : String!

        var title : String!
        var date : String!
        var description : String!
        var commentCount : Int!
        var viewsCount : Int!
        var likesCount : Int!
        var bucketsCount : Int!
        var attachmentsCount : Int!
        var reboundCount : Int!

        var user : User! 

       override init(data: NSDictionary) {
            super.init(data: data)

           self.commentCount = data["comments_count"] as! Int
            self.likesCount = data["likes_count"] as! Int
            self.viewsCount = data["views_count"] as! Int
            self.bucketsCount = data["buckets_count"] as! Int
            self.attachmentsCount = data["attachments_count"] as! Int
            self.reboundCount = data["rebounds_count"] as! Int

            self.commentsUrl = Utils.getStringFromJSON(data, key: "comments_url")
            self.bucketsUrl = Utils.getStringFromJSON(data, key: "buckets_url")
            self.likesUrl = Utils.getStringFromJSON(data, key: "likes_url")
            self.title = Utils.getStringFromJSON(data, key: "title")
            self.attachmentUrl = Utils.getStringFromJSON(data, key: "attachments_url")
            self.reboundUrl = Utils.getStringFromJSON(data, key: "rebounds_url")

            let dateInfo = Utils.getStringFromJSON(data, key: "created_at")
            self.date = Utils.formatDate(dateInfo)

            let desc = Utils.getStringFromJSON(data, key: "description")
            self.description = Utils.stripHTML(desc)

            let images = data["images"] as! NSDictionary
            self.imageUrl = Utils.getStringFromJSON(images, key: "normal")

            //let tags = data["tags"] as! NSArray

          if let userData = data["user"] as? NSDictionary {
            self.user = User(data: userData)
        }
      }
    }

和 DribbbleBase 的代码

import Foundation

class DribbbleBase {
    var id: Int

    init(data: NSDictionary){
        self.id = data["id"] as! Int
    }
}

请帮助我..请记住我对 Swift 还很陌生

提前致谢雅利安人

Answer 1

您在PopularShotsCollectionViewController中声明了shot属性，但没有初始化它，因此shot为零。然后您尝试访问 shot 的 commentsUrl 属性，该属性在 loadComments 方法中为 nil 。您应该在 View Controller 的 init 或 view did load 方法中实例化 shot