title: Delete thumbnail by id
body: <p>I use below code to get photo's path and id:</p>
  
  <pre><code>String[] projection = {MediaStore.Images.Media._ID, MediaStore.Images.Media.DATA, MediaStore.Images.ImageColumns.DATA};  
  Cursor cursor = managedQuery( MediaStore.Images.Media.EXTERNAL_CONTENT_URI, projection, null, null, MediaStore.Images.Media._ID); 
  int count = cursor.getCount();
  int image_column_index = cursor.getColumnIndex(MediaStore.Images.Media._ID); 
  int image_path_index = cursor.getColumnIndex(MediaStore.Images.Media.DATA);
  int i;
  for(i = 0; i &lt; count; i++) {
  cursor.moveToPosition(i);
  long id = cursor.getInt(image_column_index);
  String p = cursor.getString(image_path_index);
  photo.add(id, p);
  }
  </code></pre>
  
  <p>And use below code to get thumbnail:</p>
  
  <pre><code>bitmap = MediaStore.Images.Thumbnails.getThumbnail(this.getApplicationContext().getContentResolver(), id, MediaStore.Images.Thumbnails.MICRO_KIND, null);
  </code></pre>
  
  <p>While I delete one photo by its path.
  The thumbnail of the delete one's still exist.
  How to delete the thumbnail at the same time?</p>