主页面中覆盖onKeyDown方法
@Override public boolean onKeyDown(int keyCode, KeyEvent event) { // TODO Auto-generated method stub if(keyCode == KeyEvent.KEYCODE_BACK){ ShowDialog.showExitDialog(MainActivity.this); } return true; }ShowDialog.javapublic class ShowDialog{ public static void showExitDialog(Activity context){ //实例化一个关于退出的警示对话框 final AlertDialog exitDialog = new AlertDialog.Builder(context).create(); exitDialog.setTitle("提示"); exitDialog.setMessage("是否退出程序"); //点击“是”的时候触发的事件 exitDialog.setButton("是", new AlertDialog.OnClickListener(){ public void onClick(DialogInterface dialog, int which) { // TODO Auto-generated method stub exitDialog.dismiss(); System.out.println("the wopai program exit"); System.exit(0); } }); //点击“否”的时候触发的事件 exitDialog.setButton2("否", new AlertDialog.OnClickListener(){ public void onClick(DialogInterface dialog, int which) { // TODO Auto-generated method stub exitDialog.dismiss(); } }); //显示对话框 exitDialog.show(); } }