title: how to make a button get invisible in listview of an android app
body: <p>in my app i have a list view. Each list consists of a image, text and three buttons. 
  I have placed all this in a ListActivity. </p>
  
  <p>When the user clicks a particular button i use to call the download function of my app. At that time i want that button to be get invisibled. Following is the part of my code</p>
  
  <pre><code>public class Content extends ListActivity 
  {
    public void onCreate(Bundle savedInstanceState) 
      {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.main);
          adapter = new EventAdapter(this);
          setListAdapter(adapter);
      }
  
    public class InventoryAdapter extends BaseAdapter implements OnClickListener
  {        
      private Context context;   
      ImageButton b1;
      public InventoryAdapter(Context ctx) 
      {     
          context = ctx;
      }
      public long getItemId(int position) 
      {
          return position;
      }
      public View getView(int position, View convertView, ViewGroup parent)
      {
          View view;
          if(convertView == null) 
          {
              LayoutInflater inflater = (LayoutInflater)
              context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
              view = inflater.inflate(R.layout.list, null);
              b1 = (ImageButton)view.findViewById(R.id.Btn1);
              b1.setOnClickListener(this);
          }
          else 
          {
              view = convertView;
          }
          b1.setTag(position);            
          return view;
     }
  
      @Override
      public void onClick(View v) 
      {
          Log.e("onclick","onclick");
          Integer position = (Integer) v.getTag();
          switch(v.getId())
          {
              case R.id.Btn1:
                  selected_url=url[position];
                  new DownloadTask1().execute();
              break;  
          }
      }
  }    
  </code></pre>
  
  <p>How to make the a particular button to get invisibled when the a position is clicked</p>