Question

I have an activity that shows ProgressDialog while connecting to bluetooth device. It works fine until screen orientation changes while ProgressDialog is up. ProgressDialog disappears and when after connection is established, app calls progressDialog.dismiss(); at this point app crashes because there is no ProgressDialog to dismiss. How can i prevent to ProgressDialog dismissing while screen orientation changes?

public void prepareViews(int ID, boolean state){
        switch(ID){
        case USERNAME_TEXTBOX:
            LoginUsernameTextBox.setEnabled(state);
            break;
        case PASSWORD_TEXTBOX:
            LoginPasswordTextBox.setEnabled(state);
            break;
        case LOGIN_BUTTON:
            LoginButton.setEnabled(state);
            break;
        case LOGIN_PROGRESSBAR:
            if(state == true){
                LoginProgressBar.setVisibility(View.VISIBLE);
                LoginProgressBar.setIndeterminate(true); }
            else{
                LoginProgressBar.setVisibility(View.GONE);
            }
            break;
        case CONNECTING_DIALOG:
            if(state == true){
            progressDialog = ProgressDialog.show(MainActivity.this, "", "Connecting", true); }
            else{
                progressDialog.dismiss();
            }
            break;
        }
    }

Answer 1

I end up to use DialogFragment and it works.

public class MainActivity extends Activity{



    public void prepareViews(int ID, boolean state){
        switch(ID){
        case USERNAME_TEXTBOX:
            LoginUsernameTextBox.setEnabled(state);
            break;
        case PASSWORD_TEXTBOX:
            LoginPasswordTextBox.setEnabled(state);
            break;
        case LOGIN_BUTTON:
            LoginButton.setEnabled(state);
            break;
        case LOGIN_PROGRESSBAR:
            if(state == true){
                LoginProgressBar.setVisibility(View.VISIBLE);
                LoginProgressBar.setIndeterminate(true); }
            else{
                LoginProgressBar.setVisibility(View.GONE);
            }
            break;
        case CONNECTING_DIALOG:
            if(state == true){
                showDialog();
            }
            break;
        }
    }

public void showDialog() {
        FragmentManager fragmentManager = getFragmentManager();
        ProgressDialogFragment newFragment = new ProgressDialogFragment();
        newFragment.show(fragmentManager, "Dialog");
    }

public static class ProgressDialogFragment extends DialogFragment {
        @Override
        public Dialog onCreateDialog(Bundle savedInstanceState) {
            final ProgressDialog progressDialog = ProgressDialog.show(getActivity(), "", "Connecting to " 
                    + DeviceName.subSequence(0, DeviceName.length() - 17)); 
            return progressDialog;
        }
    }
}