android的上下文菜单,android上下文菜单
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android的上下文菜单,android上下文菜单
android的菜单有三种:
1.main.xml布局文件
<!--此布局文件定义了listview,用来显示一组列表,稍后上下文菜单将被注册到该listview,并且响应该listview。--> <?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/layout" android:layout_width="fill_parent" android:layout_height="fill_parent"> <ListView android:id="@+id/lv_list" android:layout_width="wrap_content" android:layout_height="fill_parent"> </ListView> </RelativeLayout>
2.item.xml布局文件,用来显示listview中的一个单独的控件
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/layout" android:layout_width="fill_parent" android:layout_height="fill_parent"> <TextView android:id="@+id/tv" android:layout_width="wrap_content" android:layout_height="fill_parent" android:textSize="20dip" > </TextView> </RelativeLayout>
3. 在layout下新建一个menu文件夹,在建一个menu.xml布局文件
<?xml version="1.0" encoding="utf-8"?> <menu xmlns:android="http://schemas.android.com/apk/res/android"> <item android:id="@+id/new_game" android:title="新游戏" /> <item android:id="@+id/help" android:title="寻求帮助" /> <item android:id="@+id/addnew" android:title="添加新游戏" /> <item android:id="@+id/delete" android:title="删除游戏" /> </menu>
4.MenuActivity.java
package org.ynu.android; import java.util.ArrayList; import java.util.HashMap; import android.app.Activity; import android.os.Bundle; import android.view.ContextMenu; import android.view.ContextMenu.ContextMenuInfo; import android.view.Menu; import android.view.MenuInflater; import android.view.MenuItem; import android.view.View; import android.view.View.OnClickListener; import android.widget.AdapterView.AdapterContextMenuInfo; import android.widget.Button; import android.widget.ListView; import android.widget.SimpleAdapter; import android.widget.TextView; import android.widget.Toast; public class MenuActivity extends Activity { private ListView lv; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); //如定义了一个listview控件 ArrayList<HashMap<String, String>> list = new ArrayList<HashMap<String,String>>(); HashMap<String, String> map1 = new HashMap<String, String>(); map1.put("item", "第一个菜单项"); HashMap<String, String> map2 = new HashMap<String, String>(); map2.put("item", "第二个菜单项"); HashMap<String, String> map3 = new HashMap<String, String>(); map3.put("item", "第三个菜单项"); HashMap<String, String> map4 = new HashMap<String, String>(); map4.put("item", "第四个菜单项"); HashMap<String, String> map5 = new HashMap<String, String>(); map5.put("item", "第五个菜单项"); list.add(map1); list.add(map2); list.add(map3); list.add(map4); list.add(map5); //初始化该控件 lv=(ListView)findViewById(R.id.lv_list); //定义适配器 参数为该显示信息用的布局文件 以及显示信息用的控件,这里是一个textview控件 SimpleAdapter adapter = new SimpleAdapter(this, list, R.layout.item, new String[]{"item"}, new int[]{R.id.tv}); lv.setAdapter(adapter); //注册上下文菜单显示用的view registerForContextMenu(this.lv); } //该方法在注册的view被被长按时创建该view的上下文菜单 @Override public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) { // TODO Auto-generated method stub MenuInflater inflater = getMenuInflater(); inflater.inflate(R.menu.menu, menu); super.onCreateContextMenu(menu, v, menuInfo); } //当菜单某个选项被点击时调用该方法 @Override public boolean onContextItemSelected(MenuItem item) { // TODO Auto-generated method stub AdapterContextMenuInfo infor = (AdapterContextMenuInfo)item.getMenuInfo(); switch(item.getItemId()) { case R.id.help: Toast.makeText(this, "请求帮助", Toast.LENGTH_LONG).show(); return true; case R.id.addnew: Toast.makeText(this, "添加新的", Toast.LENGTH_LONG).show(); return true; case R.id.delete: Toast.makeText(this, "删除信息", Toast.LENGTH_LONG).show(); return true; case R.id.new_game: Toast.makeText(this, "新游戏", Toast.LENGTH_LONG).show(); return true; default: return super.onContextItemSelected(item); } } //当上下文菜单关闭时调用的方法 @Override public void onContextMenuClosed(Menu menu) { // TODO Auto-generated method stub super.onContextMenuClosed(menu); } }
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