Nach dem Download, wie heruntergeladene Datei zu öffnen?

Question

DownloadManager.Request request = new DownloadManager.Request(uri); 
     request.setDestinationInExternalPublicDir(Environment. 
         DIRECTORY_DOWNLOADS, nameOfFile) 

Um sie zu öffnen

 File file = new File(Environment. 
        DIRECTORY_DOWNLOADS, nameOfFile); 
      MimeTypeMap map = MimeTypeMap.getSingleton(); 
      String ext = MimeTypeMap.getFileExtensionFromUrl(file.getName()); 
      String type = map.getMimeTypeFromExtension(ext); 

Aber ich erhalte eine Fehlermeldung, die Datei nicht accessed.Check die Lage

Answer 1

sein kann

Versuchen Leseberechtigung mit:

android.permission.READ_EXTERNAL_STORAGE 

Answer 2

wie Try this ...

protected void openFile(String fileName) { 
    Intent install = new Intent(Intent.ACTION_VIEW); 
    install.setDataAndType(Uri.fromFile(new File(fileName)), 
      "MIME-TYPE"); 
    startActivity(install); 
} 

Answer 3

Hier ist eine funktionierende Lösung. Hinweis: Verwenden Sie nicht DownloadManager.COLUMN_LOCAL_FILENAME, da es in API 24 veraltet ist. Verwenden Sie stattdessen DownloadManager.COLUMN_LOCAL_URI.

1. Erstellen Sie Felder Download Manager und eine lange Variable, die Download-ID zu halten.

   DownloadManager dm; 
   long downloadId; 
   String pendingDownloadUrl = url; 
   fial int storagePermissionRequestCode = 101; 
   

2. erstellen Download-Manager dm = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);

3. den Rundfunkempfänger zum Download registrieren kompletten

   BroadcastReceiver downloadCompleteReceiver = new BroadcastReceiver() { 
       @Override 
       public void onReceive(final Context context, final Intent intent) { 
        Cursor c = dm.query(new DownloadManager.Query().setFilterById(downloadId)); 
        if (c != null) { 
         c.moveToFirst(); 
         try { 
          String fileUri = c.getString(c.getColumnIndex(DownloadManager.COLUMN_LOCAL_URI)); 
          File mFile = new File(Uri.parse(fileUri).getPath()); 
          String fileName = mFile.getAbsolutePath(); 
          openFile(fileName); 
         }catch (Exception e){ 
          Log.e("error", "Could not open the downloaded file"); 
         } 
        } 
       } 
   };  
   

// registriert boradcast zum Download kompletten

registerReceiver(downloadCompleteReceiver, new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE)); 

4. Starten Sie den Download

Starten Sie den Download

private void onDownloadStart(String url) { 
if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) { 
    downloadFile(url); 
} else { 
    pendingDownloadUrl = url; 
    ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, storagePermissionRequestCode); 
} } 

// Download-Datei Download-Manager

private void downlaodFile(String url){ 
    DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url)); 
    String filename = URLUtil.guessFileName(url, null, null); 
    request.allowScanningByMediaScanner(); 
    request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED); 
    request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS,filename); 
    downloadId = dm.enqueue(request);//save download id for later reference } 

// Berechtigungsstatus

@Override public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) { 
    if(requestCode == storagePermissionRequestCode){ 
     boolean canDownload = true; 
     for (int grantResult : grantResults) { 
      if (grantResult == PackageManager.PERMISSION_DENIED) { 
       canDownload = false; 
       break; 
      } 
     } 
     if(canDownload){ 
      downlaodFile(pendingDownloadUrl); 
     } 
    }  } 

5. Öffnen Sie die heruntergeladene Datei

   private void openFile(String file) { 
   try { 
       Intent i = new Intent(Intent.ACTION_VIEW); 
       i.setDataAndType(Uri.fromFile(new File(file)), "application/pdf");//this is for pdf file. Use appropreate mime type 
       startActivity(i); 
   } catch (Exception e) {   
       Toast.makeText(this,"No pdf viewing application detected. File saved in download folder",Toast.LENGTH_SHORT).show(); 
   } 
   }

6. Jetzt versuchen die Dateien herunterladen, indem Aufruf downladFile(String url); Methode