how to access to a specific element of every grid view item

I have a gridview in which there are two elements in each of its items, the first is an image and the second is a title, the title is invisible in the launching of the application, but I have a button outside the grid view that when I click on it, I want to change the visibility of the titles of items to become visible, my problem is that I can not access each title of each item in the grid view. When I set the visibility of the titles (TextView) in the onClick method of the independent button in my activity, it changes the visibility ONLY for the FIRST item in the grid view!

This sketch represent my interface, so the titles are invisible in the beginning, but when i click on "SetVisibilityButton", i want to set them to Visible :

    Image1    Image2      Image3
    Title1    Title2      Title3

    Image4    Image5      Image6
    Title4    Title5      Title6

    Image7    Image8      Image9
    Title7    Title8      Title9


    ----------------------------
    SetVisibilityButton
    ____________________________        

I set the grid view in my oncreate() activity :

    favorGrid = (GridView) findViewById(R.id.favorGrid);
    favorGrid.setAdapter(adapter);

In my ImageAdapter class, this is my getView() method :

          @Override
       public View getView(int position, View convertView, ViewGroup parent) 
       {
          View MyView = convertView;

           /*we define the view that will display on the grid*/

             //Inflate the layout
             LayoutInflater li = getLayoutInflater();
             MyView = li.inflate(R.layout.favor_item, null);

             // Add The Text!!!
             TextView tv = (TextView)MyView.findViewById(R.id.title);
             tv.setText(mTitles[position]);

             // Add The Image!!!           
             ImageView iv = (ImageView)MyView.findViewById(R.id.favor_item_image);
             iv.setImageResource(mT