ContextMenu称为上下文菜单,一般在控件上长按时弹出。今天我们学习ContextMenu的用法,这里与listview相结合,先在ListView显示几个Item,然后在Item上长按,弹出一个菜单(就是ContextMenu),点击菜单上的项目,提示刚才长按的Item的Position. main.xml 里就一个ListView
<?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/lv"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/hello"
/>
</LinearLayout>
下面是Java代码:
package com.pocketdigi.com;
import java.util.ArrayList;
import android.app.Activity;
import android.os.Bundle;
import android.view.ContextMenu;
import android.view.ContextMenu.ContextMenuInfo;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;
public class main extends Activity {
/** Called when the activity is first created. */
ListView lv;
ArrayAdapter Adapter;
ArrayList arr=new ArrayList();
//定义菜单项
protected static final int Menu_Item1=Menu.FIRST;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
lv=(ListView)findViewById(R.id.lv);
//添加ListView项
arr.add("123");
arr.add("234");
arr.add("345");
Adapter = new ArrayAdapter(this,android.R.layout.simple_list_item_1, arr);
lv.setAdapter(Adapter);
lv.setOnCreateContextMenuListener(MenuLis);
}
ListView.OnCreateContextMenuListener MenuLis=new ListView.OnCreateContextMenuListener(){
@Override
public void onCreateContextMenu(ContextMenu menu, View v,
ContextMenuInfo menuInfo) {
// TODO Auto-generated method stub
//添加菜单项
menu.add(Menu.NONE,Menu_Item1,0,"获取position");
}
};
//选中菜单Item后触发
public boolean onContextItemSelected(MenuItem item){
//关键代码在这里
AdapterView.AdapterContextMenuInfo menuInfo;
menuInfo =(AdapterView.AdapterContextMenuInfo)item.getMenuInfo();
//输出position
Toast.makeText(main.this,String.valueOf(menuInfo.position), Toast.LENGTH_LONG).show();
return super.onContextItemSelected(item);
}
}