尝试再次查看pdf文件时，从错误线程访问的域Swift 3

我有收藏视图，用户可以点击下载pdf文件。如果下载完成，将显示pdf文件。但当pdf显示并返回后，再次点击单元格以再次显示pdf，它会抛出从错误线程访问的

域。

以下是我下载文件的代码：

func downloadData(_ magazineObject: Magazine, cell: magazineCell) {
Alamofire.download(magazineObject.urlMagazine, method: .get, encoding: JSONEncoding.default, to: destination)
        .downloadProgress(queue: DispatchQueue.global(qos: .utility)) { progress in
            DispatchQueue.main.async() {
                self.percentProgressFinal = Float(progress.fractionCompleted)

                magazineObject.progressBarDownload = progress.fractionCompleted.roundToPlaces(places: 2)
                magazineObject.progressBarTitle = Float(self.displayFinalLabelPercent).cleanValue

            }
        }
        .validate { request, response, temporaryURL, destinationURL in
            self.localPath = destinationURL
            magazineObject.pathDatabase = String(describing: self.localPath!)
            magazineObject.progressBarDownload = Double(self.percentProgressFinal)
            magazineObject.progressBarTitle = Float(self.displayFinalLabelPercent).cleanValue
            magazineObject.statusDarkViewAfterRelaunch = 1

                let mainStoryBoard:UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
                let vc:PDFKBasicPDFViewer = mainStoryBoard.instantiateViewController(withIdentifier: "NEXT") as! PDFKBasicPDFViewer
                let documentsPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]
                let filePath = "\(documentsPath)/\(magazineObject.title).pdf"

                let document: PDFKDocument = PDFKDocument(contentsOfFile: filePath, password: nil)
                vc.loadDocument(document)

                self.navigationController?.pushViewController(vc, animated: true)

            magazineObject.statusDownload = self.statusDatabase

            let realm = try! Realm()

            try! realm.write {
                realm.add(magazineObject)
            }

            return .success
    }
}

并显示文件（如果已下载）：

if statusGlobal {
        if magazineObject.statusDownload == 0 {
            magazineObject.statusDownload = 1

            //Alamofire Request
            downloadData(magazineObject, cell: cell)

            cell.progressDownload.isHidden = false
            cell.progressLabel.isHidden = false

        } else {
            let mainStoryBoard:UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
            let vc:PDFKBasicPDFViewer = mainStoryBoard.instantiateViewController(withIdentifier: "NEXT") as! PDFKBasicPDFViewer
            let documentsPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]
            let filePath = "\(documentsPath)/\(magazineObject.title).pdf"
            let document: PDFKDocument = PDFKDocument(contentsOfFile: filePath, password: nil)
            vc.loadDocument(document)

            self.navigationController?.pushViewController(vc, animated: true)
        }
    }
}

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< > P>但如果我重新运行模拟器，它可以显示我的PDF文件。

< P>用来在抛出C++异常时设置断点，然后查找抛出“不正确的线程”异常的堆栈跟踪，以查看代码的哪一行触发异常。从这里，您应该能够确定跨线程错误共享的领域对象。

我通过创建另一个变量来解决这个问题

 let newMagazineObject = Magazine()
            newMagazineObject.id = magazineObject.id
            newMagazineObject.pathDatabase = magazineObject.pathDatabase
            newMagazineObject.progressBarDownload = magazineObject.progressBarDownload
            newMagazineObject.progressBarTitle = magazineObject.progressBarTitle
            newMagazineObject.statusDarkViewAfterRelaunch = magazineObject.statusDarkViewAfterRelaunch
            newMagazineObject.statusDownload = magazineObject.statusDownload

            let realm = try! Realm()
            try! realm.write {
                realm.add(newMagazineObject)
            }

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您在上面提供的代码是您唯一获得并使用

领域的地方吗？是的，这是我唯一获得并使用领域的地方