Question

I am new to the android.os.AsyncTask approach on handling android.app.ProgressDialog. I have this problem of processing a particular query via android.database.Cursor and convert in into an entity I would need.

I am following this template but it always return me an android.view.WindowManager$BadTokenException.

List<Entity> loadData() throws Exception {
    AsyncTask<Cursor, Void, List<Entity>> process = new AsyncTask<Cursor, Void, List<Entity>>() {
        ProgressDialog dialog;
        protected void onPreExecute() {
            dialog = ProgressDialog.show(getApplicationContext(), "Please wait...", "Loading data...");         
        }
        protected void onPostExcecute() {
            dialog.dismiss();
        }
        @Override
        protected List<Entity> doInBackground(Cursor... params) {
            List<Entity> entities = new ArrayList<Entity>();
            // process of convertion of data from android.database.Cursor to <pacakge>.Entity
            return entities;
        }
    }.execute(/* the query : android.database.Cursor */)
    return process.get();
}

Am I missing something?

Answer 1

to show ProgressDialog from onPreExecute() method of AsyncTask use Current Activity Context in which AsyncTask is running instead of getApplicationContext() as :

 dialog = ProgressDialog.show(Your_Current_Activity.this, 
                    "Please wait...",
                    "Loading data...");

if AsyncTask is running in separate class from Activity then you will need to pass current activity context in AsyncTask using AsyncTask’s class constructor