alert_dialog.java

//declare diatas method
//variable global
final Context context = this;

=================================================================
//simpan dalam method
// set title
               
                AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(context);
                alertDialogBuilder.setTitle("Perhatian!");

                // set dialog message
                alertDialogBuilder
                        .setMessage("Apakah anda ingin keluar dari aplikasi ini?")
                        .setCancelable(true)
                        .setNegativeButton("Batal", new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                                //MenuActivity.this.finish();
                                dialog.dismiss();
                            }
                        })
                        .setPositiveButton("Keluar",new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog,int id) {
                                // if this button is clicked, close
                                // current activity
                                finish();
                                System.exit(0);
                                //MainActivity.this.finish();
                            }
                        });

                // create alert dialog
                AlertDialog alertDialog = alertDialogBuilder.create();

                // show it
                alertDialog.show();