onKeyDown Method override in android

hi all i have a problem in my application please see the code below for reference. the problem that i am facing is that when i click on Back Key Button from my Simulator i want my application to ask me that Are you sure you want to exit. and when i press Yes then it should exit otherwise it should not. i have done all the things but when i click on the back key button it shows me a dialog and exits automatically. whats the reason

code:

@Override
public boolean onKeyDown(int keyCode, KeyEvent event)  {
    if (keyCode == KeyEvent.KEYCODE_BACK) {

    AlertDialog.Builder alert_wifi = new AlertDialog.Builder(this);
            alert_wifi.setMessage("This is a Wi-Fi Service. Your Device does not have an active Wi-Fi Connection. Do you Want to Activate Wi-Fi Connection")
            .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int id) {
                // Action for 'Yes' Button

                    dialog.dismiss();

                 ViewCamera.isStop = true;

                }
                })
            .setNegativeB开发者_如何转开发utton("No", new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int id) {
                //  Action for 'NO' Button
                dialog.cancel();
                loading_act.finish();
                }
            });
            AlertDialog alert = alert_wifi.create();
            // Title for AlertDialog
            alert.setTitle("Caution!");
            alert.setIcon(R.drawable.wifi);
            // Icon for AlertDialog
            alert.show();

     }

    return super.onKeyDown(keyCode, event);
}

what could be the problem please help

return super.onKeyDown(keyCode, event);

Change it return true;

Calling super makes activity perform the default behaviour, so it exits.

Try adding this method

@Override
    public void onBackPressed() {
    ...
    }