@Override public boolean onCreateOptionsMenu(Menu menu){   MenuInflater inflater = getMenuInflater();   inflater.inflate(R.menu.main, menu);   return true; } 

<menu xmlns:android="http://schemas.android.com/apk/res/android" >   <item     android:id="@+id/action_cart"     android:title="掃描"     android:orderInCategory="100"     android:showAsAction="always"/> </menu> 

@Override  public boolean onOptionsItemSelected(MenuItem item){   switch (item.getItemId()) {   case R.id.action_cart://監聽菜單按鈕          break;   }   return super.onOptionsItemSelected(item); }