Android ProgressDialog未显示

Question

Here is the part of my code connected to the dialog. After they press the button, it should show up and after showing up, the it should process the data and when its done, it should hide away. But it doesen't even appear?

ProgressDialog dialog = new ProgressDialog(this);
dialog.setMessage("Prosimo počakajte da naloži podatke.");
dialog.setIndeterminate(false);
dialog.setCancelable(false);
dialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);

private Button.OnClickListener listener = new Button.OnClickListener() {
    public void onClick(View v){
        if(selectedClass >= 0){
            dialog.show();

            ... data processing ...

            Intent firstUpdate = new Intent(context, ConfigurationActivity.class);
            firstUpdate.setAction("android.appwidget.action.APPWIDGET_ENABLED");
            firstUpdate.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, widget_id);
            context.sendBroadcast(firstUpdate);

            dialog.dismiss();
            setResult(RESULT_OK, firstUpdate); 
            finish(); 
        } else {
            Log.i("Schedule", "Missing selections");
        }
    }
};

Thanks for any help.

Answer 1

Thanks to "Pragnani" I have managed to make it work. Here is the final code:

private class ProgressTask extends AsyncTask<String, Void, Boolean> 
{
    private ProgressDialog dialog;
    private ConfigurationActivity activity;

    public ProgressTask(ConfigurationActivity activity) 
    {
        this.activity = activity;
        context = activity;
        dialog = new ProgressDialog(context);
    }

    private Context context;

    protected void onPreExecute() 
    {
        dialog = new ProgressDialog(context);
        dialog.setMessage("Prosimo počakajte da naloži podatke.");
        dialog.setIndeterminate(false);
        dialog.setCancelable(false);
        dialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
        dialog.show();
    }

    @Override
    protected void onPostExecute(final Boolean success) 
    {
        if (dialog.isShowing()) 
                    {
            dialog.dismiss();
        }
        if (success) 
                    {
            Toast.makeText(context, "OK", Toast.LENGTH_LONG).show();
        } 
                    else 
                    {
            Toast.makeText(context, "ERROR", Toast.LENGTH_LONG).show();
        }
    }

    @Override
    protected Boolean doInBackground(final String... args) 
    {
        try {    
            ... processing ...

            return true;
        } catch (Exception e){
            Log.e("Schedule", "UpdateSchedule failed", e);
            return false;
        }
    }

}

Calling the class:

new ProgressTask(ConfigurationActivity.this).execute();

Thanks Pragnani !