Question

我有一个子菜单，在xml中设置按钮，工作正常。

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
<!-- Single menu item
     Set id, icon and Title for each menu item
-->
 <item android:id="@+id/menu_level"
      android:title="Set Level" >
      <menu>
          <group android:checkableBehavior="single">
            <item android:id="@+id/one"
                  android:checked="false"
                  android:title="One" />
            <item android:id="@+id/two"
                  android:title="Two" />
            <item android:id="@+id/three"
                  android:title="Three" />
         </group>
     </menu>
 </item>

<item android:id="@+id/menu_save"
      android:icon="@drawable/icon_save"
      android:title="Save" />

 <item android:id="@+id/menu_about"
      android:icon="@drawable/icon_bookmark"
      android:title="About">

     <menu>
         <item  android:id="@+id/copyright"
                android:title="(c) John Beukema 2012">
         </item>
     </menu>

   <item/>
</menu>

我按如下方式访问它：

@Override
public boolean onOptionsItemSelected(MenuItem item)
{
    Editor editor = PreferenceManager
            .getDefaultSharedPreferences(this).edit();


    switch (item.getItemId())
    {

    case R.id.menu_save:
        return true;

    case R.id.menu_recall:
        return true;

    case R.id.menu_level: {
        return true;    
    }
    case R.id.menu_about:

        return true;

    case R.id.one:
        star = 1;
        editor.putInt("Star", 1);              
        editor.commit();
        item.setChecked(true);
        return true;

    case R.id.two:
        star = 2;
        editor.putInt("Star", 2);              
        editor.commit();
        item.setChecked(true);
        return true;

    case R.id.three:
        star = 3;
        editor.putInt("Star", 3);              
        editor.commit();
        item.setChecked(true);
        return true;

    case R.id.menu_delete:
        return true;

    case R.id.menu_preferences:
        return true;

    default:
        return super.onOptionsItemSelected(item);
    }
   } 
}

到目前为止没问题。但是我想从首选项启动时加载按钮。

@SuppressWarnings("deprecation")
@SuppressLint("NewApi")
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    SharedPreferences preferences = PreferenceManager
          .getDefaultSharedPreferences(this);



    star = preferences.getInt("Star", 1);

    MenuItem one = (MenuItem) findViewById(R.id.one);
    MenuItem  two = (MenuItem ) findViewById(R.id.two);
    MenuItem  three = (MenuItem) findViewById(R.id.three);

    switch(star)  
    {
    case 1:
        one.setChecked(true); break;



    case 2:
        two.setChecked(true); break;

    case 3:
        three.setChecked(true); break
        } 
   }
}

这编译但挂起。如何处理子菜单按钮？

Answer 1

我认为你不能在menuitem上做findviewbyid。您需要在onprepareoptionsmenu

中设置或取消设置选中的项目

单击菜单前的android子菜单按钮项目访问权限

1 个答案: