Question

I m完全是新到的Anthony(Java)发展,I m如此夸大了! 谷歌的制定者指南是弹性的,我在一个小的时间内学到了很多东西。它甚至在晚上让我觉醒;

今天我接着说,我可以理解一些东西。它涉及扩大课程。该指南说:

Tip: If your application contains multiple activities and some of them provide the same Options Menu, consider creating an activity that implements nothing except the onCreateOptionsMenu() and onOptionsItemSelected() methods. Then extend this class for each activity that should share the same Options Menu. This way, you have to manage only one set of code for handling menu actions and each descendant class inherits the menu behaviors.

我看不出的是,如何扩大一等。我要说的是MainActative和SubActative。在这两项活动中,我想有相同的菜单,这样我就有了<>MainMenuActative。我如何将这一类别扩大到这两种活动?

是的,我确实在网上搜查了,但却找不到任何东西。我真的想理解这一点,因此我希望任何人都能够帮助我解答某些条码加解释。 advance!

Answer 1

它们的含义如下:

通常,你会:

public class MyActivity extends Activity{...}

如果这些活动中有4-5-6,其中每一个活动都使用相同的菜单,那么你就能够照抄和复制第4-5-6号法律。或者你可以这样做:

public class BaseActivity extends Activity{
    
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        //My menu code  
    }
}

并且将这一类别用于你的4-5-6...... 活动:

public class MyActivity extends BaseActivity{...}

这样,你就不需要把你的菜单复制到你所有的造物。此外,你的活动不一定是4-5-6. 班级将小块菜单的制造线ed。菜单现在也载于<编码>。 MyActative。

http://xahlee.info/java-a-day/extend.html” rel=“nofollow noreferer”>here,其中解释了extends的含义。

Answer 2

这确实非常简单。

http://www.ohchr.org。

public class MainMenuActivity extends Activity {
   //Override or add whatever functionality you want other classes to inherit.
}

http://www.ohchr.org。

public class MainActivity extends MainMenuActivity {
   //Add what is specific to MainActivity. The menu will be inherited from MainMenuActivity.
}

http://www.ohchr.org。

public class SubActivity extends MainMenuActivity {
   //Add what is specific to SubActivity. The menu will be inherited from MainMenuActivity.
}

友情链接