Question

I have an activity that queries a server database and returns a list of results…while querying the app displays a simple progressDialog on the onCreate method like so:

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

//display progress dialog while querying server for values
        final ProgressDialog dialog = ProgressDialog.show(this,"","Retrieving listings please wait...");
        dialog.setCancelable(true);
        dialog.show();

If the user clicks on an item from the list then another activity placeDetails is opened. Once done a user can press the back button to go back to the previous activity which displays the listings.

When I tested it naturally it shows the above dialog and sends the query back to the server even though the listings can be seen in the background of the progressDialog.

What I want to know is how would I prevent the database being queried again and the above progressDialog from displaying when the user presses the back button.

Do I have to go down the caching route? or is there another way?

Answer 1

I managed to solve this issue the missing link was I did not know how to check for dialog windows the following code helped:

//first declare the dialog so its accessible globally through out the class
public class ListPlaces extends ListActivity {
 ProgressDialog dialog;

then on the onCreate first check that a dialog exists or not

if(dialog == null){
            dialog = ProgressDialog.show(this,"","Retrieving listings please wait...");
            //display progress dialog while querying server for values
            dialog.setCancelable(true);
            dialog.show();
        } 

And the mistake was I was using

dialog.hide();

instead of
dialog.dismiss();

Thanks for the contributions