swift - WKDownloadDelegate 下载失败并出现错误 -3000

Question

当使用新的 WKDownloadDelegate 时，我尝试下载一个文件，第一次下载正常，但是当我再次尝试下载同一个文件时，WKDownloadDelegate 调用了这个方法:

func download(_ download: WKDownload, didFailWithError error: Error, resumeData: Data?)

当我将其打印到控制台时:

download(_ download: <WKDownload: 0x7fc58fb2dfd0>, didFailWithError error: The operation couldn’t be completed. (NSURLErrorDomain error -3000.), resumeData: nil

问题是我找不到关于此错误 (-3000) 的任何信息，所以任何建议都很好。

这是整个 WKDownloadDelegate 代码

    public func download(_ download: WKDownload, decideDestinationUsing response: URLResponse, suggestedFilename: String, completionHandler: @escaping (URL?) -> Void) {
    let tempDirectory = FileManager.default.temporaryDirectory
    let tempFolderName = UUID().uuidString
    let tempDirectoryPath = tempDirectory.appendingPathComponent(tempFolderName)
    try? FileManager.default.createDirectory(at: tempDirectoryPath, withIntermediateDirectories: false)
    let url = tempDirectory.appendingPathComponent(suggestedFilename)
    currentDownloadedPreviewItemUrl = url
    completionHandler(url)
}

public func downloadDidFinish(_ download: WKDownload) {
    guard let currentDownloadedPreviewItemUrl = currentDownloadedPreviewItemUrl else {
        print("Download finished but no URL found")
        return
    }

    DispatchQueue.main.async {
        let activityVC = UIActivityViewController(activityItems: [currentDownloadedPreviewItemUrl], applicationActivities: nil)
        activityVC.popoverPresentationController?.sourceView = self.view
        activityVC.popoverPresentationController?.sourceRect = self.view.frame
        activityVC.popoverPresentationController?.barButtonItem = self.navigationItem.rightBarButtonItem
        self.present(activityVC, animated: true, completion: nil)
    }
}

public func download(_ download: WKDownload, didFailWithError error: Error, resumeData: Data?) {
    debugPrint("------------------")
    debugPrint("download(_ download: \(download), didFailWithError error: \(error.localizedDescription), resumeData: \(resumeData)")
    debugPrint("------------------")
}

Answer 1

我很笨拙，所以我会为任何再次遇到错误 -3000 的人发布问题所在。使用 WKDownloadDelegate 和方法时

func download(_ download: WKDownload, decideDestinationUsing response: URLResponse, suggestedFilename: String, completionHandler: @escaping (URL?) -> Void)

被调用时，将 URL 传递给完成处理程序时，您必须确保不存在同名文件，否则稍后会在 downloadDidFail 方法中抛出错误。

所以在我的例子中，我修复了这个方法中的代码:

public func download(_ download: WKDownload, decideDestinationUsing response: URLResponse, suggestedFilename: String, completionHandler: @escaping (URL?) -> Void) {
    let tempDirectory = FileManager.default.temporaryDirectory
    let tempFolderName = UUID().uuidString
    let tempDirectoryPath = tempDirectory.appendingPathComponent(tempFolderName)
    do {
        try FileManager.default.createDirectory(at: tempDirectoryPath, withIntermediateDirectories: false)
    } catch {
        debugPrint(error)
    }
    let url = tempDirectoryPath.appendingPathComponent(suggestedFilename)
    currentDownloadedPreviewItemUrl = url
    completionHandler(url)
}

注意那一行

let url = tempDirectoryPath.appendingPathComponent(suggestedFilename)

正在使用 tempDirectoryPath 而不是 tempDirectory