从 webview 下载文件到内部存储

Question

以下代码可以完美地下载外部存储中的 mp3 文件，但不能下载内部存储中的文件。许多智能手机没有外部存储。我能做些什么？如果需要的话，我不知道如何在 kotlin 中实现异步任务。

 mywebView.setDownloadListener(object : DownloadListener {
        override fun onDownloadStart(url: String, userAgent: String,
                                     contentDisposition: String, mimetype: String,
                                     contentLength: Long) {


            val request = DownloadManager.Request(Uri.parse(url))
            request.allowScanningByMediaScanner()
            request.setDescription("Download file...")
            request.setTitle(URLUtil.guessFileName(url, contentDisposition, mimetype))

            request.setAllowedNetworkTypes(DownloadManager.Request.NETWORK_WIFI or DownloadManager.Request.NETWORK_MOBILE)
            request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED) //Notify client once download is completed!
            request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, mimetype )
            val webview = getSystemService(DOWNLOAD_SERVICE) as DownloadManager
            webview.enqueue(request)

            Toast.makeText(getApplicationContext(), "Download avviato", Toast.LENGTH_LONG).show()

        }
    })

Answer 1

目前无法测试代码，但应该如下所示：

 mywebView.setDownloadListener(object : DownloadListener {
        override fun onDownloadStart(url: String, userAgent: String,
                                     contentDisposition: String, mimetype: String,
                                     contentLength: Long) {


            val request = DownloadManager.Request(Uri.parse(url))
            request.allowScanningByMediaScanner()
            request.setDescription("Download file...")
            request.setTitle(URLUtil.guessFileName(url, contentDisposition, mimetype))

            request.setAllowedNetworkTypes(DownloadManager.Request.NETWORK_WIFI or DownloadManager.Request.NETWORK_MOBILE)
            request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED) //Notify client once download is completed!
            request.setDestinationInExternalPublicDir(Environment.getExternalStorageDirectory(), mimetype )
            val webview = getSystemService(DOWNLOAD_SERVICE) as DownloadManager
            webview.enqueue(request)

            Toast.makeText(getApplicationContext(), "Download avviato", Toast.LENGTH_LONG).show()

        }
    })