DownloadManager 中未显示进度搜索栏通知 android

Question

我正在从 webview 下载文件。但是在使用 DownloadManager 时，它不会显示类似于 this 的正在进行的下载通知。它只是在后台运行。如何在下载过程中显示状态栏通知。我可以获取下载的文件，但如何在通知中显示正在进行的过程？

我使用了 "request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE);" 但它没有显示正在进行的过程。请指导我我在做什么错误。

这是我使用的代码。

mWebview.setDownloadListener(new DownloadListener() {
            @Override
            public void onDownloadStart(String url, String userAgent, String contentDisposition, String mimetype, long contentLength) {
                DownloadManager.Request request = new DownloadManager.Request(
                        Uri.parse(url));
                request.setMimeType("pdf");


                String cookies = CookieManager.getInstance().getCookie(url);


                request.addRequestHeader("cookie", cookies);


                request.addRequestHeader("User-Agent", userAgent);


                request.setDescription("Downloading file...");


                request.setTitle(URLUtil.guessFileName(url, contentDisposition,
                        "pdf"));


                request.allowScanningByMediaScanner();
                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
      //clueless why it's not working..    
    request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE);
                } else {
                    request.setShowRunningNotification(true);
                }

                //request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
                request.setDestinationInExternalPublicDir(
                        Environment.DIRECTORY_DOWNLOADS, URLUtil.guessFileName(
                                url, contentDisposition, "pdf"));
                dm = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);
                downloadReference = dm.enqueue(request);
                IntentFilter filter = new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE);
                registerReceiver(downloadReceiver, filter);
            }
        });
    }

    private BroadcastReceiver downloadReceiver = new BroadcastReceiver() {

        @Override
        public void onReceive(Context context, Intent intent) {
            long referenceId = intent.getLongExtra(DownloadManager.EXTRA_DOWNLOAD_ID, -1);
            if (downloadReference == referenceId) {
                DownloadManager.Query q = new DownloadManager.Query();
                q.setFilterById(intent.getLongExtra(DownloadManager.EXTRA_DOWNLOAD_ID, -1));
                Cursor c = dm.query(q);

                if (c.moveToFirst()) {
                    int status = c.getInt(c.getColumnIndex(DownloadManager.COLUMN_STATUS));
                    if (status == DownloadManager.STATUS_SUCCESSFUL) {
                        // process download
                        String title = c.getString(c.getColumnIndex(DownloadManager.COLUMN_TITLE));
                        File file = new File(Environment.getExternalStorageDirectory()
                                + "/Download/" + title);//name here is the name of any string you want to pass to the method
                        if (!file.isDirectory())
                            file.mkdir();
                        //Intent testIntent = new Intent("com.adobe.reader");
                        Intent testIntent = new Intent(Intent.ACTION_VIEW);
                        testIntent.setType("application/pdf");
                        //testIntent.setAction(Intent.ACTION_VIEW);
                        Uri uri = Uri.fromFile(file);
                        testIntent.setDataAndType(uri, "application/pdf");
                        try {
                            startActivity(testIntent);
                        } catch (ActivityNotFoundException e) {
                            Toast.makeText(MainActivity.this, "No application available to view PDF",
                                    Toast.LENGTH_SHORT).show();
                        }
                        // get other required data by changing the constant passed to getColumnIndex
                    }
                }
            }
        }
    };

我签入了 Android 7.1.1.

Answer 1

是的，我找到了解决方案。问题是没有启用下载管理器。

Go to the Settings > App
In the options click 'Show System Apps'
Find 'Download Manager' and open it
Click 'Notifications' under App Settings
Switch on Allow Notifications

参考：

DownloadManager 中未显示进度搜索栏通知 android

On progress seekbar notification not showing in DownloadManager android

android

android-notifications

android-download-manager