Get an image resource from external content resolver randomly in Android.

getRandomExternalImageContent.java

protected static Uri getRandomExternalImageContent(Context c) {
	ContentResolver resolver = c.getContentResolver();
	if (resolver == null)
		return null;
	
	String [] proj = { MediaStore.Images.Media.DATA };
	Cursor cursor = resolver.query(Images.Media.EXTERNAL_CONTENT_URI, proj, null, null, null);
	
	int count = cursor.getCount();
	int position = (int) (Math.random() * count);
	if (! cursor.moveToPosition( position ) ) {
		return null;
	}
	
	int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
	String path = cursor.getString(column_index); 
	cursor.close();
	return Uri.fromFile(new File(path));
}