androoid framework学习之 - ContextMenu上下文菜单

来源：互联网发布：包头稀土高新区大数据编辑：程序博客网时间：2024/05/16 09:11

转载自http://stephen830.iteye.com/blog/1130637

Android 菜单(ContextMenu)

Android 的ContextMenu，即上下文菜单。（类似电脑上的鼠标右键功能，选中某个元素，然后点右键，在弹出菜单上执行操作。）在手机上，通过长时间按住界面上的元素，就会出现事先设计好的上下文菜单。

主要用到的方法有：

Java代码  
// 创建显示上下文菜单  
setOnCreateContextMenuListener  
  
//监听长按事件  
setOnItemLongClickListener  
  
//监听普通按键事件  
setOnItemClickListener  
  
//上下文菜单的选中事件  
onContextItemSelected  
  
//监听上下文菜单关闭事件  
onContextMenuClosed  

示例（ListView上下文菜单）

效果图

main_list_view.xml 配置

Xml代码  
<?xml version="1.0" encoding="utf-8"?>  
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  
    android:orientation="vertical"  
    android:layout_width="fill_parent"  
    android:layout_height="fill_parent"  
    >  
<ListView  
    android:id="@+id/main_list_view_listview"  
    android:layout_width="fill_parent"  
    android:layout_height="fill_parent"  
    />  
</LinearLayout>  

main_list_view_item.xml配置

Xml代码  
<?xml version="1.0" encoding="utf-8"?>  
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  
    android:id="@+id/RelativeLayout_Item"  
    android:layout_width="fill_parent" android:layout_height="wrap_content"  
    android:paddingBottom="5dip"  
    >  
    <TextView   
        android:id="@+id/main_list_view_item_item_text"  
        android:layout_centerHorizontal="true"   
        android:layout_width="wrap_content"  
        android:layout_height="wrap_content"   
        android:textSize="20px"  
        android:layout_gravity="center"  
        />  
</LinearLayout>  

Activity代码

Java代码  
package com.zhouzijing.android;  
  
import java.util.ArrayList;  
import com.zhouzijing.android.util.MenuEntity;  
import com.zhouzijing.android.util.SimpleAdapterUtil;  
import android.app.Activity;  
import android.content.Context;  
import android.os.Bundle;  
import android.view.ContextMenu;  
import android.view.Menu;  
import android.view.MenuItem;  
import android.view.View;  
import android.view.ContextMenu.ContextMenuInfo;  
import android.view.View.OnCreateContextMenuListener;  
import android.widget.AdapterView;  
import android.widget.AdapterView.OnItemLongClickListener;  
import android.widget.ListView;  
import android.widget.SimpleAdapter;  
import android.widget.Toast;  
import android.widget.AdapterView.OnItemClickListener;  
  
public class Menu2 extends Activity {  
    final Context context = this;  
    //定义1个ListView  
    private ListView listView = null;  
    //定义ListView需要显示的数据  
    private ArrayList<ArrayList<Object>> viewInfos = null;  
    //定义上下文菜单  
    final private static int CONTEXT_MENU_EDIT = 0;//菜单[编辑]的编号   
    final private static int CONTEXT_MENU_SHARE = 1;//菜单[分享]的编号   
    final private static int CONTEXT_MENU_DELETE = 2;//菜单[删除]的编号   
    final private static int CONTEXT_MENU_CANCEL = 3;//菜单[取消]的编号   
    private int itemLongClickSelected = 0;  
    private MenuEntity[] contextMenus = {  
            new MenuEntity(0, CONTEXT_MENU_EDIT, 0, "编辑"),  
            new MenuEntity(0, CONTEXT_MENU_SHARE, 1, "分享"),  
            new MenuEntity(0, CONTEXT_MENU_DELETE, 2, "删除"),  
            new MenuEntity(0, CONTEXT_MENU_CANCEL, 3, "取消"),  
            };  
  
    @Override  
    public void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.main_list_view);  
        //初始化要显示的内容  
        initListViewInfos();  
        //显示ListView  
        showListView();  
        //显示ListView的上下文菜单  
        showListViewContextMenu();  
    }  
      
    /** 
     * 初始化ListView需要显示的内容. 
     */  
    public void initListViewInfos(){  
        viewInfos = new ArrayList<ArrayList<Object>>();  
        ArrayList<Object> countrys = new ArrayList<Object>();  
        countrys.add("Austria");  
        countrys.add("China");  
        countrys.add("Egypt");  
        countrys.add("France");  
        countrys.add("Ireland");  
        countrys.add("Japan");  
        countrys.add("Spain");  
        countrys.add("United Kingdom");  
        countrys.add("United States");  
        viewInfos.add(countrys);  
    }  
      
    /** 
     * 从ListView显示内容中删除1条记录. 
     */  
    public void removeItem(int index){  
        viewInfos.get(0).remove(index);  
    }  
    /** 
     * 从ListView显示内容中读取1条记录 
     * @param index 
     * @return 
     */  
    public Object readItem(int index){  
        return viewInfos.get(0).get(index);  
    }  
      
    /** 
     * 读取当前执行的菜单 
     * @param index 
     * @return 
     */  
    public CharSequence readContextMenu(int index){  
        for(int i=0;i<contextMenus.length;i++){  
            if(contextMenus[i].getItemId()==index) return contextMenus[i].getTitle();  
        }  
        return "";  
    }  
    /** 
     * 显示ListView. 
     */  
    public void showListView(){  
        final Context context = this;  
          
        //定义适配器to参数  
        int[] to = {R.id.main_list_view_item_item_text};  
        int resource = R.layout.main_list_view_item;  
          
        //生成适配器:使用自定义工具类 SimpleAdapterUtil.java来生成适配器  
        SimpleAdapter simpleAdapter = SimpleAdapterUtil.create(context,viewInfos,resource,to);   
          
        listView = (ListView)findViewById(R.id.main_list_view_listview);  
        listView.setAdapter(simpleAdapter);  
    }  
    /** 
     * 显示ListView的上下文菜单 
     */  
    public void showListViewContextMenu(){  
        //创建上下文菜单  
        listView.setOnCreateContextMenuListener(new OnCreateContextMenuListener(){  
  
            @Override  
            public void onCreateContextMenu(ContextMenu menu, View v,  
                    ContextMenuInfo menuInfo) {  
                menu.setHeaderTitle(readItem(itemLongClickSelected).toString());  
                MenuEntity menuEntity = null;  
                for(int i=0;i<contextMenus.length;i++){  
                    menuEntity = contextMenus[i];  
                    menu.add(menuEntity.getGroupId(),menuEntity.getItemId(),menuEntity.getOrder(),menuEntity.getTitle());  
                }  
            }  
        });  
          
        //监听列表项目的长按事件  
        listView.setOnItemLongClickListener(new OnItemLongClickListener(){  
  
            @Override  
            public boolean onItemLongClick(AdapterView<?> parent, View view,  
                    int position, long id) {  
                itemLongClickSelected = position;  
                Toast.makeText(context,"item["+position+":"+readItem(itemLongClickSelected).toString()+"]被长时间点击了.",Toast.LENGTH_SHORT).show();  
                return false;  
            }  
              
        });  
          
        //监听列表项目的普通点击事件  
        listView.setOnItemClickListener(new OnItemClickListener(){  
  
            @Override  
            public void onItemClick(AdapterView<?> parent, View view,  
                    int position, long id) {  
                Toast.makeText(context,"item["+position+":"+readItem(position).toString()+"]被点击了.",Toast.LENGTH_SHORT).show();  
            }  
        });  
    }  
  
    @Override  
    public boolean onContextItemSelected(MenuItem item) {//执行上下文菜单中的菜单  
        int itemId = item.getItemId();  
        Toast.makeText(context,"Context menu item["+itemId+":"+readContextMenu(itemId)+"] is Selected.",Toast.LENGTH_SHORT).show();  
        if(CONTEXT_MENU_DELETE==itemId){//删除  
            //当前选中的ListView中的item编号  
            int index = itemLongClickSelected;  
            //在当前ListView中删除选中的元素  
            removeItem(index);  
            //重新显示ListView  
            showListView();  
        }  
        return super.onContextItemSelected(item);  
    }  
  
    @Override  
    public void onContextMenuClosed(Menu menu) {//关闭上下文菜单  
        Toast.makeText(context,"Context Menu is Closed.",Toast.LENGTH_SHORT).show();  
        super.onContextMenuClosed(menu);  
    }  
      
      
}  

备注：

Java代码  
private MenuEntity[] contextMenus = {  
            new MenuEntity(0, CONTEXT_MENU_EDIT, 0, "编辑"),  
            new MenuEntity(0, CONTEXT_MENU_SHARE, 1, "分享"),  
            new MenuEntity(0, CONTEXT_MENU_DELETE, 2, "删除"),  
            new MenuEntity(0, CONTEXT_MENU_CANCEL, 3, "取消"),  
            };  

参考关于菜单基础属性的实体类

Java代码  
SimpleAdapter simpleAdapter = SimpleAdapterUtil.create(context,viewInfos,resource,to);   

参考 1个简单的SimpleAdapter工具类-SimpleAdapterUtil（版本二：数据格式为ArrayList<ArrayList<Object>>）

关于根据上下文菜单来获取当前选中的GridView(或ListView等)的元素

Java代码  
        //OnCreateContextMenuListener  
        gridPhoneBook.setOnCreateContextMenuListener(new OnCreateContextMenuListener(){  
            @Override  
            public void onCreateContextMenu(ContextMenu menu, View v,  
                    ContextMenuInfo menuInfo) {  
                //获取上下文菜单点击的GridView中的元素  
                AdapterContextMenuInfo info = (AdapterContextMenuInfo) menuInfo;  
                int position = info.position;  
                //设置上下文菜单的标题  
                PhoneBook phoneBook = (PhoneBook)phoneBookAdapter.getItem(position);  
                menu.setHeaderTitle(phoneBook.getName());  
                //设置上下文菜单  
                MenuEntity menuEntity;  
                for(int i=0;i<CONTEXT_MENUS.length;i++){  
                    menuEntity = CONTEXT_MENUS[i];  
                    menu.add(menuEntity.getGroupId(), menuEntity.getItemId()  
                            ,menuEntity.getOrder(),menuEntity.getTitle());  
                }  
            }  
        });   
      
  
/** 
     * 上下文菜单-具体菜单的执行操作. 
     */  
    @Override  
    public boolean onContextItemSelected(MenuItem item) {  
          
        //获取选中的GridView的元素  
        AdapterContextMenuInfo info = (AdapterContextMenuInfo)item.getMenuInfo();  
        int position = info.position;  
        PhoneBook phoneBook = (PhoneBook)phoneBookAdapter.getItem(position);  
        //菜单ID  
        int menuId = item.getItemId();  
        switch(menuId){  
        case CONTEXT_MENU_PHONE_BOOK_DELETE:  
            doContextMenuOfDelete(phoneBook);  
            break;  
        }  
        return super.onContextItemSelected(item);  
    }  

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