下載後如何打開下載的文件？

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

要打開它下載後如何打開下載的文件？

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

但我得到該文件不能accessed.Check位置的錯誤消息

來源

2016-04-21 Agniveer Kranti

你有所需的權限下載你的文件？ – camelCaseCoder

是的我有<使用權限android：name =「android.permission.WRITE_EXTERNAL_STORAGE」/> <使用權限android：name =「android.permission.ACCESS_DOWNLOAD_MANAGER」/> @camelCaseCoder –

好吧，文件路徑是否正確？你在Android 6上測試這個嗎？ – camelCaseCoder

嘗試使用讀取權限：

android.permission.READ_EXTERNAL_STORAGE

來源

2016-04-21 10:18:18

沒有得到相同的錯誤 –

嘗試這樣...

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

來源

2016-04-21 10:21:02

你也可以在這裏看到一個例子https://github.com/commonsguy/cw-android/blob/master/Internet/Download/src/ com/commonsware/android/download/DownloadDemo.java –

我已經創建了一個dir最終文件folder = new File（Environment.getExternalStorageDirectory（）+「Wonders」）;布爾成功= true; if（！folder.exists（））{ success = folder.mkdir（）;如何設置路徑request.setDestinationInExternalPublicDir（Environment.DIRECTORY_DOWNLOADS，****** here **** ，nameOfFile）@saurabh gupta –

這是一個工作解決方案。注意：不要使用DownloadManager.COLUMN_LOCAL_FILENAME，因爲它在API 24中不推薦使用。請改用DownloadManager.COLUMN_LOCAL_URI。

創建字段downlaod manager和一個長變量來保存下載ID。

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

創建下載管理器 dm = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);

註冊廣播接收器下載完整

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"); 
      } 
     } 
    } 
};

//註冊boradcast下載完整

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

開始下載

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); 
} }

//下載文件使用下載管理器

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 }

//權限狀態

@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); 
     } 
    }  }

打開下載的文件

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(); 
} 
}

現在嘗試通過調用downladFile(String url);方法

來源

2017-09-20 17:48:04

下載後如何打開下載的文件？

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