Question

I have a class which extends Activity this class job is to get some data from a SQLite database on the phone, and init. a ListView with all the data from the database.

This is the method for getting information from the database:

public ArrayList<Case> getFromDatabase() {

    ArrayList<Case> c = db1.getAllContacts();    
    return c; 
}

As earlier mentioned this method is inside a class that extends Activity This method is called in the onCreate method. This operation takes about 2 second if the database contains around 15 records. How can I show a ProgressDialog, when user presses the button to start this activity, just to show that something is happening?

Answer 1

Create ProgressDialog as field of the activity by declaring an ProgressDialog variable outside onCreate method:

ProgressDialog pd=null;

Create a Handler as field in Activty, by writing following block outside of onCreate method.

Handler handler=new Handler()
{
   public void handleMessage(Message msg)
   {
      pd.dismiss();
      //do other operations on EventThread.
      ArrayList<Case> c= (ArrayList<Case>)msg.obj;
      //Process c
   }
}

now in onCreate method replace your code with following:

pd=ProgressDialog.show(YourActivity.this, "title", "subtitle");
Thread thread=new Thread()
{
   public void run()
   {
       ArrayList<Case> c = db1.getAllContacts();
       Message msg=handler.obtainMessage();
       msg.obj=c;
       handler.sendMessage(msg);
   }
};
thread.start();