I always found the following answer for my Question:
context.sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED, Uri.parse("file://"
+ Environment.getExternalStorageDirectory())));
but it do not work on my System (Nexus4 Android 4. ...)
I can create a File and add it to the Media-DB whith this code
Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
Uri contentUri = Uri.fromFile(file);
mediaScanIntent.setData(contentUri);
context.sendBroadcast(mediaScanIntent);
Where "file" is the new image-file i want to add.
after deleting the File I try to refresch the gallery by
Intent intent = new Intent(Intent.ACTION_MEDIA_MOUNTED);
Uri contentUri = Uri.parse("file://" + Environment.getExternalStorageDirectory());
intent.setData(contentUri);
context.sendBroadcast(intent);
or
context.sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED, Uri.parse("file://"
+ Environment.getExternalStorageDirectory())));
but there are still empty placeholder in the Galery.
I do not know why?...
To be on the safe side I add too my Activity in the AndroidManifest.xml
<intent-filter>
<action android:name="android.intent.action.MEDIA_MOUNTED" />
<data android:scheme="file" />
</intent-filter>
but the result is the same. Any idea to solve the problem?