WKDownloadDelegate下载失败，错误代码为-3000。

Question

使用新的WKDownloadDelegate时，我尝试下载一个文件，第一次下载成功，但当我再次尝试下载同一文件时，WKDownloadDelegate会调用此方法:

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

当我将此内容打印到控制台时：

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

问题是我找不到与此错误（-3000）相关的任何信息，所以希望有任何建议。

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("------------------")
}

- OldTimes

Answer 1

我很笨拙，所以我会把问题写下来，以便再次遇到错误-3000的人可以参考。当使用WKDownloadDelegate和该方法时

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

当传递URL到完成处理程序时，将调用该方法。您必须确保不存在同名文件，否则稍后会在downloadDidFail方法中引发错误。

因此，在我的情况下，我修复了此方法的代码：

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)
}

请注意该行。

let url = tempDirectoryPath.appendingPathComponent(suggestedFilename)

使用tempDirectoryPath而不是tempDirectory

- OldTimes