當(dāng)Activity在前臺運行時，如果用戶按下手機(jī)上的Menu鍵，此時就會在屏幕低端彈出相應(yīng)的選項菜單。但這個功能需要開發(fā)人員編程來實現(xiàn)的，如果在開發(fā)應(yīng)用程序時沒有實現(xiàn)該功能，那么程序運行時按下手機(jī)的meun鍵是不會起作用的。

對于攜帶圖標(biāo)的選項菜單，每次最多只能顯示6個，當(dāng)菜單選項多于6個時，將只顯示前5個和一個擴(kuò)展菜單選項，點擊擴(kuò)展菜單選項將會彈出其余的菜單項。擴(kuò)展菜單項中將不會顯示圖標(biāo)，但是可以顯示單選按鈕和復(fù)選框。

以下模擬選項菜單

main.xml布局文件：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout android:id="@+id/LinearLayout01"
  android:layout_width="fill_parent" 
  android:layout_height="fill_parent"
  android:orientation="vertical"
  xmlns:android="http://schemas.android.com/apk/res/android">
  <ScrollView android:id="@+id/scrollView"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">
    <EditText android:id="@+id/editText"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent" 
      android:editable="false"
      android:cursorVisible="false" 
      android:text="您的選擇為\n">
    </EditText>
  </ScrollView>
</LinearLayout>

MeunActivity類：

package com.ljq.activity;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.SubMenu;
import android.view.MenuItem.OnMenuItemClickListener;
import android.widget.EditText;
public class MeunActivity extends Activity {
  private final int MENU_GENDER_MALE = 0; 
  private final int MENU_GENDER_FEMALE = 1;
  private final int MENU_HOBBY1 = 2; 
  private final int MENU_HOBBY2 = 3;
  private final int MENU_HOBBY3 = 4; 
  private final int MENU_OK = 5; 
  private final int MENU_GENDER = 6;
  private final int MENU_HOBBY = 7; 
  private final int GENDER_GROUP = 0;
  private final int HOBBY_GROUP = 1; 
  private final int MAIN_GROUP = 2; 
  MenuItem[] hoddyMenuItems = new MenuItem[3];// 愛好菜單項組
  MenuItem maleMenuItem = null;// 男性菜單項
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
  }
  /**j
   * 初始化選項菜單
   */
  @Override
  public boolean onCreateOptionsMenu(Menu menu) {
    //單選菜單選項
    SubMenu genderMenu = menu.addSubMenu(MAIN_GROUP, MENU_GENDER, 0, "性別");
    genderMenu.setIcon(R.drawable.gender);
    genderMenu.setHeaderIcon(R.drawable.gender);
    maleMenuItem = genderMenu.add(GENDER_GROUP, MENU_GENDER_MALE, 0, "男");
    maleMenuItem.setChecked(true);
    genderMenu.add(GENDER_GROUP, MENU_GENDER_FEMALE, 0, "女");
    //設(shè)置菜單項為單選菜單項，互斥的
    genderMenu.setGroupCheckable(GENDER_GROUP, true, true);
    //復(fù)選菜單選項
    SubMenu hobbyMenu = menu.addSubMenu(MAIN_GROUP,MENU_HOBBY,0,"愛好");
    hobbyMenu.setIcon(R.drawable.hobby);
    hobbyMenu.setHeaderIcon(R.drawable.hobby);
    hoddyMenuItems[0]=hobbyMenu.add(HOBBY_GROUP, MENU_HOBBY1, 0, "游泳");
    hoddyMenuItems[1]=hobbyMenu.add(HOBBY_GROUP, MENU_HOBBY2, 0, "唱歌");
    hoddyMenuItems[2]=hobbyMenu.add(HOBBY_GROUP, MENU_HOBBY3, 0, "編程");
    //設(shè)置菜單項為復(fù)選菜單項
    hoddyMenuItems[0].setCheckable(true);
    hoddyMenuItems[1].setCheckable(true);
    hoddyMenuItems[2].setCheckable(true);
    //確定菜單項
    MenuItem ok=menu.add(MAIN_GROUP,MENU_OK,0,"確定");
    ok.setOnMenuItemClickListener(new OnMenuItemClickListener(){
      public boolean onMenuItemClick(MenuItem item) {
        appendStateStr();
        return true;
      }
    });
    //給確定菜單項添加快捷鍵
    ok.setAlphabeticShortcut('o');//設(shè)置字符快捷鍵
    //ok.setNumericShortcut('1');//設(shè)置數(shù)字快捷鍵
    //ok.setShortcut('a', '2');//同時設(shè)置兩種快捷鍵。注意：同時設(shè)置多次時只有最后一個設(shè)置起作用
    return true; // 記得返回true，否則無效
  }
  /**
   * 在菜單選項中某個選項被選中時調(diào)用該事件
   */
  @Override
  public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
    case MENU_GENDER_MALE:
     case MENU_GENDER_FEMALE:
       item.setChecked(true); 
       appendStateStr();
       break;  
     case MENU_HOBBY1:
     case MENU_HOBBY2:
     case MENU_HOBBY3:
      item.setChecked(!item.isChecked());
      appendStateStr();
      break;  
    }
    return true;
  }
  public void appendStateStr() {
    String result = "您選擇的性別為：";
    if (maleMenuItem.isChecked()) {
      result = result + "男";
    } else {
      result = result + "女";
    }
    String hobbyStr = "";
    for (MenuItem hoddy : hoddyMenuItems) {
      if (hoddy.isChecked()) {
        hobbyStr = hobbyStr + hoddy.getTitle() + "、";
      }
    }
    if (hobbyStr.length() > 0) {
      result = result + ",您的愛好為："
          + hobbyStr.substring(0, hobbyStr.length() - 1) + "。\n";
    } else {
      result = result + "。\n";
    }
    EditText et = (EditText) MeunActivity.this.findViewById(R.id.editText);
    et.append(result);
  }
}

運行結(jié)果：