Android: Problem with Media Scanner not Running

Question

I have an app that user's can draw with, and then 'export' that drawing as a .png file to external storage, if present. Generating the PNG, copying the file to external all work like a charm, but a rather unique problem happens; after the export, if the user navigates to the image via My files (Samsung Tab running 2.2 in this case), they can see the .png file, but when they open it, the screen is black for about 10 seconds... then they see the image, Additionally, the images don't show up in the user's 'Gallery' app either.

Now, if the user connects the device to the computer via USB, or reboots the device, they can access the images no problem from My files, and they appear in 'Gallery' from that point forward, but again, any newly esported files experience the same problems until they cycle/connect the device again.

My thinking was that this had to be related to the Media Scanner (at least in the case of the 'Gallery' problem, it most certainly is).

So, as I am targetting Api 8+, I am trying to use the static MediaScannerConnection.scanFile() method to have the OS re-scan and add my images into the Gallery, etc. Also hoping this solves the issue of the strange delay in opening the images. Here is my code:

MediaScannerConnection.scanFile(
  context, 
  new String[] { "/mnt/sdcard/MyApp" }, 
  null, 
  null
);

LogCat gives me the following entries when I export an image, and thus run the above call:

DEBUG/MediaScannerService(2567): IMediaScannerService.scanFile: /mnt/sdcard/MyApp mimeType: null
DEBUG/MediaScannerService(2567): onStartCommand : intent - Intent { cmp=com.android.providers.media/.MediaScannerService (has extras) }
DEBUG/MediaScannerService(2567): onStartCommand : flags [0], startId [1]
DEBUG/MediaScannerService(2567): ServiceHandler:handleMessage volume[null], filePath[/mnt/sdcard/MyApp]
DEBUG/MediaProvider(2567): getSdSerial() sd state = removed
INFO/Database(2567): sqlite returned: error code = 17, msg = prepared statement aborts at 43: [SELECT DISTINCT sd_serial FROM images WHERE sd_serial LIKE 'external_0x%']
ERROR/MediaProvider(2567): removeMediaDBData called
DEBUG/MediaScanner(2567): prescan enter: path - /mnt/sdcard/MyApp
DEBUG/MediaScanner(2567): prescan return

So, it looks like the MediaScanner is getting the correct location, but is failing to find the SD card, which is correct, and failing. The Samsung Tab has built-in non-SD external storage, which Android gives access to via Environment.getExternalStorageDirectory(). How do I tell it to scan the non-SD storage?

Any ideas how to proceed?

Paul

Answer 1

Found the solution here, which involves sending a broadcast request to the media scanner via an Intent:

How to update the Android media database

Never did figure out the issue with MediaScannerConnection.scanFile.

Answer 2

Whenever you add a file, let MediaStore Content Provider knows about it using

sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, Uri.fromFile(imageAddedOrDeleted)));

Main advantage: work with any mime type supported by MediaStore

For deletion: just use getContentResolver().delete(uri, null, null)