Android应用中使用Popupmenu

最终效果：

页面布局：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="#FFFFFF"
    android:orientation="vertical" >

    <RelativeLayout
        android:layout_width="fill_parent"
        android:layout_height="45dp"
        android:background="#303538" >
        <Button
            android:id="@+id/button_showPopup"
            android:layout_width="wrap_content"
            android:layout_height="fill_parent"
            android:layout_alignParentRight="true"
            android:background="#303538"
            android:text="┇"
            android:textColor="#FFFFFF"
            android:textSize="20sp" >
        </Button>
    </RelativeLayout>

</LinearLayout>

Popupmenu布局（文件在menu目录下）：

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android" >

    <item
        android:id="@+id/about"
        android:orderInCategory="100"
        android:showAsAction="never"
        android:title="关于">
    </item>
    <item
        android:id="@+id/exit"
        android:orderInCategory="100"
        android:showAsAction="never"
        android:title="退出">
    </item>

</menu>

后台代码：

package com.wangzhen.popup;

import android.app.Activity;
import android.os.Bundle;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.Window;
import android.widget.Button;
import android.widget.PopupMenu;
import android.widget.Toast;

public class Main extends Activity implements OnClickListener,
        android.widget.PopupMenu.OnMenuItemClickListener {
    /** Called when the activity is first created. */
    private Button button_showPopup;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.main);
        initViews();
    }

    // 初始化控件
    private void initViews() {
        // TODO Auto-generated method stub
        button_showPopup = (Button) findViewById(R.id.button_showPopup);
        button_showPopup.setOnClickListener(this);
    }

    public void onClick(View arg0) {
        // TODO Auto-generated method stub
        switch (arg0.getId()) {
        case R.id.button_showPopup:
            PopupMenu pop = new PopupMenu(this, arg0);
            pop.getMenuInflater().inflate(R.menu.menu, pop.getMenu());
            pop.show();
            pop.setOnMenuItemClickListener(this);
            break;
        }
    }

    public boolean onMenuItemClick(MenuItem arg0) {
        // TODO Auto-generated method stub
        switch (arg0.getItemId()) {
        case R.id.about:
            Toast.makeText(this, "关于", 1000).show();
            break;
        case R.id.exit:
            finish();
            break;
        }
        return false;
    }
}