下载完成后从错误的线程访问领域 Swift 3

Posted 2023-03-12

【中文标题】下载完成后从错误的线程访问领域 Swift 3

【英文标题】：Realm accessed from incorrect thread after download completed Swift 3

【发布时间】：2016-12-27 04:00:51

【问题描述】：

我有一个应用程序，用户可以下载 pdf 文件。我最近搬到了 alamofire 4 和 swift 3。我尝试在下载完成后查看 pdf 文件，但它抛出 Realm accessed from incorrect thread.

这是我的代码：

Alamofire.download(url, method: .get, encoding: JSONEncoding.default, to: destination)
        .downloadProgress(queue: DispatchQueue.global(qos: .utility))  progress in

            DispatchQueue.main.async 
                magazineObject.progressBarDownload = self.percentProgress
                magazineObject.progressBarTitle = self.percentProgressNext.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
            magazineObject.statusDownload = self.statusDatabase

            try! realm.write 
                realm.add(magazineObject)
            
            return .success
    

【参考方案1】：

尝试在validate 块内创建另一个领域线程对象

.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
    magazineObject.statusDownload = self.statusDatabase

   // create new object here 
   let realm = try! Realm()

    try! realm.write 
        realm.add(magazineObject)
    
    return .success

您可以在领域文档https://realm.io/docs/swift/latest/#using-a-realm-across-threads查看详细信息