//d打開(kāi)菜單
????public?void?openMenu()
????{
????????if(isOpen)?return;
????????this.smoothScrollTo(0,0);
????????isOpen=true;
????}
????//關(guān)閉菜單
????public?void?closeMenu()
????{
????????if(!isOpen)return;
????????this.smoothScrollTo(mMenuWidth,0);
????????isOpen=false;
????}
//切換菜單

????@Override
????public?boolean?onKeyDown(int?keyCode,?KeyEvent?event)?{

????????if(keyCode==KeyEvent.KEYCODE_BACK)
????????{
???????????closeMenu();
????????}
????????return?super.onKeyDown(keyCode,?event);
???????/*?return?isOpen=false;*/
????}

????public?void?toggle(){


????????if(isOpen)
????????{
????????????closeMenu();
????????}else
????????{
????????????openMenu();
????????}
????}

請(qǐng)問(wèn)如何監(jiān)聽(tīng)手機(jī)返回按鍵，，將菜單欄關(guān)閉，而不是直接退出程序。