Question

I am working on an Android app which will support the Ice cream sandwich API but work on older devices such as running android 2.1.

I’m doing this by doing a check of what the current API version is, and if its post ice cream sandwich call one activity and then if its anything below, call a different activity.

I am allowing the user to perform a search, when it gets the results it then clears ArrayList and then adds the items from the search back in, and then calls the arrayadapter.notifydatasetchanged. This code I’ve copied and pasted from the ICS version into the pre ICS version, the ICS works fine but on the pre ics version the list view doesn’t get updated. Below is the code that I have.

public void performSearch(ArrayList<Spanned> searchPasswords)
    {
        if (searchPasswords.size() > 0)
        {
            btnClearSearch.setVisibility(View.VISIBLE);
            passwords.clear();
            for (int i = 0; i < searchPasswords.size(); i++)
            {
                passwords.add(searchPasswords.get(i));
            }

            passwordArrayAdapter.notifyDataSetChanged();
            btnClearSearch.setOnClickListener(mBtnClearSearch);
            common.showToastMessage(searchPasswords.size() + " result(s) found", Toast.LENGTH_LONG);
        }
        else
        {
            common.showToastMessage("No search results found", Toast.LENGTH_LONG);
        }
    }

I’ve debugged this function so it is definetely calling it, and its displaying the toast messags with saying how many results were found, but the list view doesn’t get changed.

Update

I have just made a discovery which is a bit confusing. As a test in the function that does the initial loading of the list view I manually create a new search ArrayList<Spanned> and pass this to the same PerformSearch(ArrayList<Spanned>) that I am having the problem with and this works without any problems.

The problem with the performSearch not updating the ListView only seems to happen when it is being called from onActivityResult. I know that onActivityResult is working fine as when the performSearch function is called it then prints out there is 1 result(s) found so its definitely got data just the list view doesn’t get refreshed from the onActivityResult calling the performSearch function.

Answer 1

Thanks everyone for your help and suggestions, I’ve managed to find out what the problem was.

In my OnResume method for the activity I call a function called populateListArray which retrieves all of the information from the database and lists in the ListView.

When the activity was returned it was calling the OnResume method so after it got the results it then reset the list view back with all the original content.

To get round it I added a variable called performingSearch which I initialise to false. When I perform the search I set this to true and in the onResume, if the variable is true I don’t do anything and after the perform search function has finished I set the variable back to false again.

Thanks everyone again for your help