Creating a ContextMenu on a ListView

 

layout中的main.xml

 

XML:

<?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" >      <TextView           android:layout_width ="fill_parent"           android:layout_height ="wrap_content"           android:text ="Long-Press on of the Items in the list." />      <ListView android:id ="@+id/list_favorites"           android:layout_width ="fill_parent"           android:layout_height ="fill_parent" /> </LinearLayout>

 

 

源代码是：

 

package com.gggeye.study;

import java.util.ArrayList;

import android.app.Activity;
import android.os.Bundle;
import android.view.ContextMenu;
import android.view.MenuItem;
import android.view.View;
import android.view.ContextMenu.ContextMenuInfo;
import android.view.View.OnCreateContextMenuListener;
import android.widget.ArrayAdapter;
import android.widget.ListView;
 

public class ContextMenuSample extends Activity {

     // ===========================================================
     // Final Fields
     // ===========================================================
     protected static final int CONTEXTMENU_DELETEITEM = 0;

     // ===========================================================
     // Fields
     // ===========================================================

     protected ListView mFavList;
     protected ArrayList<Favorite> fakeFavs = new ArrayList<Favorite>();

     // ===========================================================
     // "Constructors"
     // ===========================================================

     /** Called when the activity is first created. */
     @Override
     public void onCreate(Bundle icicle) {
          super.onCreate(icicle);
          setContentView(R.layout.main);

          /* Add some items to the list the listview will be showing. */
          fakeFavs.add(new Favorite("John", "nice guy"));
          fakeFavs.add(new Favorite("Yasmin", "hot girl"));
          fakeFavs.add(new Favorite("Jack", "cool guy"));

          this.mFavList = (ListView) this.findViewById(R.id.list_favorites);
          initListView();
     }

     private void refreshFavListItems() {
          mFavList.setAdapter(new ArrayAdapter<Favorite>(this,
                    android.R.layout.simple_list_item_1, fakeFavs));
     }

     private void initListView() {
          /* Loads the items to the ListView. */
          refreshFavListItems();

          /* Add Context-Menu listener to the ListView. */
          mFavList.setOnCreateContextMenuListener(new OnCreateContextMenuListener() {

               public void onCreateContextMenu(ContextMenu conMenu, View view , ContextMenuInfo info) {
                    conMenu.setHeaderTitle("ContextMenu");
                    conMenu.add(0, 0, 0, "Delete this favorite!");
                  
                    /* Add as many context-menu-options as you want to. */
               }
          });
     }

     // ===========================================================
     // Methods from SuperClass/Interfaces
     // ===========================================================

     @Override
     public boolean onContextItemSelected(MenuItem aItem) {
          ContextMenuInfo menuInfo = (ContextMenuInfo) aItem.getMenuInfo();

          /* Switch on the ID of the item, to get what the user selected. */
          switch (aItem.getItemId()) {
               case CONTEXTMENU_DELETEITEM:
                    /* Get the selected item out of the Adapter by its position. */
                    Favorite favContexted = (Favorite) mFavList.getAdapter()
                         .getItem(0);
                    /* Remove it from the list.*/
                    fakeFavs.remove(favContexted);

                    refreshFavListItems();
                    return true; /* true means: "we handled the event". */
          }
          return false;
     }

     // ===========================================================
     // Inner and Anonymous Classes
     // ===========================================================

     /** Small class holding some basic */
     protected class Favorite {

          protected String name;
          protected String kindness;

          protected Favorite(String name, String kindness) {
               this.name = name;
               this.kindness = kindness;
          }

          /** The ListView is going to display the toString() return-value! */
          public String toString() {
               return name + " (" + kindness + ")";
          }

          public boolean equals(Object o) {
               return o instanceof Favorite && ((Favorite) o).name.compareTo(name) == 0;
          }
     }
}