Android学习笔记之PopupMenu弹出菜单

（1）布局文件：用于弹出菜单的处罚button：

<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:onClick="showPopup"
        android:text="弹出菜单" />

</RelativeLayout>

<menu xmlns:android="http://schemas.android.com/apk/res/android" >

    <item
        android:id="@+id/open"
        android:orderInCategory="100"
        android:showAsAction="never"
        android:title="@string/open"/>
    <item
        android:id="@+id/close"
        android:orderInCategory="100"
        android:showAsAction="never"
        android:title="@string/close"/>

</menu>

package com.example.menu_popupmenu;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.PopupMenu;

public class MainActivity extends Activity {

	private Button button;

	@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.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;
	}

}