title: how to show dialog while doInBackground(). Asynctask
body: <p>I'm triying to do a task with an Asynctask in android. </p>
  
  <pre><code>class GetItemNames extends AsyncTask&lt;CosmeConnection, String, String&gt; {
  
      @Override
      protected void onPreExecute() {
          super.onPreExecute();
      }
  
      @Override
      protected String doInBackground(CosmeConnection... cosme) {
          ContentValues cv;
          cosme[0].orderListOfNames();
          while(!(cosme[0].getState() == CosmeStates.RECEIVED_LIST_OF_NAMES)){}
          DBHandler dbHandler = new DBHandler(getApplicationContext());
          SQLiteDatabase db = dbHandler.getReadableDatabase();
          if(db != null){
              db.delete(DBHandler.TABLE_SERVER_ITEM, null, null);
  
              String[] nombres = cosme[0].getExistingNames().getListOfNames().toString().replaceAll("[\\[\\]]", "").split(",");
              for (String str : nombres){
                  cv = new ContentValues();
                  cv.put(DBHandler.SERVER_ITEM_NAME, str);
                  cv.put(DBHandler.SERVER_ITEM_NAME, "N");
                  try{
                      db.insert(DBHandler.TABLE_SERVER_ITEM, null, cv);
                  }catch (Exception e){
                      e.printStackTrace();
                  }
              }
          }
          db.close();
          dbHandler.close();
          return null;
      }
  
      @Override
      protected void onProgressUpdate(String... progress) {
  
      }
  
      @Override
      protected void onPostExecute(String result) {
  
      }
  }
  </code></pre>
  
  <p>I'm launching this asyncktask like this:</p>
  
  <pre><code>new GetItemNames().execute(cosme, null, null);  
  </code></pre>
  
  <p>I want to show a dialog wiht the message "obtaining lis of names from server" while doInBackGround() is running. I tried to do in this way:</p>
  
  <pre><code>protected void onProgressUpdate(String... progress) {
          String title = getString(R.string.received_list_of_names_title);
          String msg = getString(R.string.received_list_of_names_msg);
          DialogHelper.getAlertDialog(getApplicationContext(), title, msg);
  }
  </code></pre>
  
  <p>DialogHelper is just a class that manage dialogs, getAlertDialog() mehots is showing an normal alert dialog with a title and a message.</p>
  
  <p>But this is nor working, i can't figure how to show a dialog that opens automaticlly and close when "doInBackGround()" has finished. </p>
  
  <p>How can i do this?</p>
  
  <p>Thanks a lot!</p>
  
  <p>EDIT: after try the suggestion i have this exception:</p>
  
  <pre><code>09-21 14:07:21.966: E/AndroidRuntime(22016): FATAL EXCEPTION: main
  09-21 14:07:21.966: E/AndroidRuntime(22016): Process: tfc.unizar.blasmobile, PID: 22016
  09-21 14:07:21.966: E/AndroidRuntime(22016): android.view.WindowManager$BadTokenException: Unable to add window -- token null is not for an application
  09-21 14:07:21.966: E/AndroidRuntime(22016):    at android.view.ViewRootImpl.setView(ViewRootImpl.java:643)
  09-21 14:07:21.966: E/AndroidRuntime(22016):    at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:261)
  09-21 14:07:21.966: E/AndroidRuntime(22016):    at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:69)
  09-21 14:07:21.966: E/AndroidRuntime(22016):    at android.app.Dialog.show(Dialog.java:286)
  09-21 14:07:21.966: E/AndroidRuntime(22016):    at tfc.unizar.blasmobile.BagContent$GetItemNames.onPreExecute(BagContent.java:263)
  09-21 14:07:21.966: E/AndroidRuntime(22016):    at android.os.AsyncTask.executeOnExecutor(AsyncTask.java:587)
  09-21 14:07:21.966: E/AndroidRuntime(22016):    at android.os.AsyncTask.execute(AsyncTask.java:535)
  09-21 14:07:21.966: E/AndroidRuntime(22016):    at tfc.unizar.blasmobile.BagContent.onOptionsItemSelected(BagContent.java:133)
  09-21 14:07:21.966: E/AndroidRuntime(22016):    at android.app.Activity.onMenuItemSelected(Activity.java:2633)
  09-21 14:07:21.966: E/AndroidRuntime(22016):    at com.android.internal.policy.impl.PhoneWindow.onMenuItemSelected(PhoneWindow.java:1040)
  09-21 14:07:21.966: E/AndroidRuntime(22016):    at com.android.internal.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:735)
  09-21 14:07:21.966: E/AndroidRuntime(22016):    at com.android.internal.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:152)
  09-21 14:07:21.966: E/AndroidRuntime(22016):    at com.android.internal.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:874)
  09-21 14:07:21.966: E/AndroidRuntime(22016):    at com.android.internal.view.menu.MenuPopupHelper.onItemClick(MenuPopupHelper.java:184)
  09-21 14:07:21.966: E/AndroidRuntime(22016):    at android.widget.AdapterView.performItemClick(AdapterView.java:299)
  09-21 14:07:21.966: E/AndroidRuntime(22016):    at android.widget.AbsListView.performItemClick(AbsListView.java:1152)
  09-21 14:07:21.966: E/AndroidRuntime(22016):    at android.widget.AbsListView$PerformClick.run(AbsListView.java:3014)
  09-21 14:07:21.966: E/AndroidRuntime(22016):    at android.widget.AbsListView$3.run(AbsListView.java:3865)
  09-21 14:07:21.966: E/AndroidRuntime(22016):    at android.os.Handler.handleCallback(Handler.java:808)
  09-21 14:07:21.966: E/AndroidRuntime(22016):    at android.os.Handler.dispatchMessage(Handler.java:103)
  09-21 14:07:21.966: E/AndroidRuntime(22016):    at android.os.Looper.loop(Looper.java:193)
  09-21 14:07:21.966: E/AndroidRuntime(22016):    at android.app.ActivityThread.main(ActivityThread.java:5296)
  09-21 14:07:21.966: E/AndroidRuntime(22016):    at java.lang.reflect.Method.invokeNative(Native Method)
  09-21 14:07:21.966: E/AndroidRuntime(22016):    at java.lang.reflect.Method.invoke(Method.java:515)
  09-21 14:07:21.966: E/AndroidRuntime(22016):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:824)
  09-21 14:07:21.966: E/AndroidRuntime(22016):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:640)
  09-21 14:07:21.966: E/AndroidRuntime(22016):    at dalvik.system.NativeStart.main(Native Method)
  </code></pre>
  
  <p>The application is closed by force after this. Any suggestion?</p>