Android之菜单一——选项菜单

Android平台下所提供的菜单大体上可分为三类：选项菜单、上下文菜单和子菜单。

当Activity在前台运行时，如果用户按下手机上的Menu键，此时就会在屏幕低端弹出相应的选项菜单。但这个功能需要开发人员编程来实现的，如果在开发应用程序时没有实现该功能，那么程序运行时按下手机的meun键是不会起作用的。

对于携带图标的选项菜单，每次最多只能显示6个，当菜单选项多于6个时，将只显示前5个和一个扩展菜单选项，点击扩展菜单选项将会弹出其余的菜单项。扩展菜单项中将不会显示图标，但是可以显示单选按钮和复选框。

以下模拟选项菜单

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="您的选择为\n">        </EditText>    </ScrollView></LinearLayout>

MeunActivity类

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];// 爱好菜单项组    MenuItem maleMenuItem = null;// 男性菜单项    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);    }    /**j     * 初始化选项菜单     */    @Override    public boolean onCreateOptionsMenu(Menu menu) {        //单选菜单选项        SubMenu genderMenu = menu.addSubMenu(MAIN_GROUP, MENU_GENDER, 0, "性别");        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");        //设置菜单项为单选菜单项，互斥的        genderMenu.setGroupCheckable(GENDER_GROUP, true, true);                //复选菜单选项        SubMenu hobbyMenu = menu.addSubMenu(MAIN_GROUP,MENU_HOBBY,0,"爱好");        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, "编程");        //设置菜单项为复选菜单项        hoddyMenuItems[0].setCheckable(true);        hoddyMenuItems[1].setCheckable(true);        hoddyMenuItems[2].setCheckable(true);                //确定菜单项        MenuItem ok=menu.add(MAIN_GROUP,MENU_OK,0,"确定");        ok.setOnMenuItemClickListener(new OnMenuItemClickListener(){            public boolean onMenuItemClick(MenuItem item) {                appendStateStr();                return true;            }        });        //给确定菜单项添加快捷键        ok.setAlphabeticShortcut('o');//设置字符快捷键        //ok.setNumericShortcut('1');//设置数字快捷键        //ok.setShortcut('a', '2');//同时设置两种快捷键。注意：同时设置多次时只有最后一个设置起作用        return true; // 记得返回true，否则无效    }        /**     * 在菜单选项中某个选项被选中时调用该事件     */    @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 = "您选择的性别为：";        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 + ",您的爱好为："                    + hobbyStr.substring(0, hobbyStr.length() - 1) + "。\n";        } else {            result = result + "。\n";        }        EditText et = (EditText) MeunActivity.this.findViewById(R.id.editText);        et.append(result);    }}

运行结果

1、2、

3、4、