Android--第一行代码笔记（2）

最新推荐文章于 2025-03-10 13:47:43 发布

原创最新推荐文章于 2025-03-10 13:47:43 发布 · 322 阅读

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本文介绍如何在Android应用中创建和使用菜单。首先在res/menu下建立XML布局文件定义菜单项，然后通过重写Activity中的onCreateOptionsMenu()方法加载菜单布局，并通过onOptionsItemSelected()方法为菜单项添加点击事件。

</pre>Activity //包含用户界面的组件，主要用于和用户交互<p></p><p>Menu使用方法；</p><p><span style="white-space:pre"></span>在res目录中新建一个menu文件夹，在menu中新建一个xml文件</p><p><span style="white-space:pre"></span>main.xml</p><p><span style="white-space:pre"></span></p><pre style="background-color:#2b2b2b; color:#a9b7c6; font-family:'Consolas'; font-size:15.0pt"><span style="color:#e8bf6a"><menu </span><span style="color:#bababa">xmlns:</span><span style="color:#9876aa">android</span><span style="color:#bababa">=</span><span style="color:#6a8759">"http://schemas.android.com/apk/res/android"</span><span style="color:#e8bf6a">>
</span><span style="color:#e8bf6a">    <item
</span><span style="color:#e8bf6a">        </span><span style="color:#9876aa">android</span><span style="color:#bababa">:id=</span><span style="color:#6a8759">"@+id/add_item"
</span><span style="color:#6a8759">        </span><span style="color:#9876aa">android</span><span style="color:#bababa">:title=</span><span style="color:#6a8759">"Add"
</span><span style="color:#6a8759">        </span><span style="color:#e8bf6a">></item>
</span><span style="color:#e8bf6a">    <item
</span><span style="color:#e8bf6a">        </span><span style="color:#9876aa">android</span><span style="color:#bababa">:id=</span><span style="color:#6a8759">"@+id/remove_item"
</span><span style="color:#6a8759">        </span><span style="color:#9876aa">android</span><span style="color:#bababa">:title=</span><span style="color:#6a8759">"Remove"
</span><span style="color:#6a8759">        </span><span style="color:#e8bf6a">></item>
</span><span style="color:#e8bf6a"></menu></span>

</pre><pre name="code" class="html">

这里面写的是menu中有几个控件，

然后再Activity中重写 onCreateOptionsMenu()方法，

public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.main1,menu);
    return true;
}

给menu添加事件响应，重写onOptionsItemSelected()方法

public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
        case R.id.add_item:
            Toast.makeText(this, "You clicked Add", Toast.LENGTH_SHORT).show();
            break;
        case R.id.remove_item:
            Toast.makeText(this, "You clicked Remove", Toast.LENGTH_SHORT).show();
            break;
        default:
    }
    return true;
}