弹出菜单是停靠在一个View上的一个模式菜单。

假设View对象下方有空间，那么弹出菜单将显示在停靠对象的下方，否则会显示在上方。

这是很实用的：

源代码地址：http://download.csdn.net/detail/u013922681/8951537

文章引用：

mod=viewthread&tid=83489">1.Android 关于PopupMenu的演示样例
2.Android应用中菜单(Menu)的位置显示问题

源代码：
MainActivity.java

package com.example.popMenu;

import android.os.Bundle;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.PopupMenu;
import android.widget.PopupMenu.OnMenuItemClickListener;
import android.widget.Toast;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    public void showPopup(View view) {
        PopupMenu popupMenu = new PopupMenu(MainActivity.this, view);
        popupMenu.getMenuInflater().inflate(R.menu.main, popupMenu.getMenu());
        popupMenu.setOnMenuItemClickListener(new OnMenuItemClickListener() {

            @Override
            public boolean onMenuItemClick(MenuItem item) {
                // TODO Auto-generated method stub
                switch (item.getItemId()) {
                case R.id.action_settings:
                    Toast.makeText(MainActivity.this, "click", 0).show();
                    break;

                default:
                    break;
                }
                return false;
            }
        });
        popupMenu.show();
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // TODO Auto-generated method stub
        switch (item.getItemId()) {
        case R.id.action_settings:
            Toast.makeText(MainActivity.this, "click", 0).show();
            break;

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

}

activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_marginLeft="96dp"
        android:layout_marginTop="111dp"
        android:text="@string/hello_world" 
        android:onClick="showPopup"/>

</RelativeLayout>

效果