DownloadManager從資產文件夾中下載文件？ （Android Studio）

Question

我正在制作一個音板應用程序，希望用戶能夠從資產下載文件，以便他們可以將其設置為通知聲音/鈴聲。 我收到一條錯誤消息，說我只能從HTTP / HTTPS下載文件。 有沒有解決的辦法？

DownloadManager.Request request = new DownloadManager.Request(Uri.parse("content://com.thingy.app/" + filename));
request.setDescription("Soundbite from ");
request.setTitle(filename);
request.allowScanningByMediaScanner();
request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, filename);
DownloadManager manager = (DownloadManager) getSystemService(Context.DOWNLOAD_SERVICE);
manager.enqueue(request);

Answer 1

使用AssetManager 及其open()方法獲取資產內容上的InputStream 。 然后，將字節復制到要創建的文件上的FileOutputStream 。

Answer 2

我使用它來將SQLite數據庫從Assets文件夾復制到內部存儲中：

        //Open your local db as the input stream
    InputStream myInput = myContext.getAssets().open(DB_IN);

    // Path to the just created empty db
    String outFileName = DB_PATH + DB_NAME;

    //Open the empty db as the output stream
    OutputStream myOutput = new FileOutputStream(outFileName);

    //transfer bytes from the input file to the output file
    byte[] buffer = new byte[1024];
    int length;
    while ((length = myInput.read(buffer))>0){
        myOutput.write(buffer, 0, length);
    }

    //Close the streams
    myOutput.flush();
    myOutput.close();
    myInput.close();