给一个控件加下上文菜单(ContextMenu)Creating a ContextMenu on a View

给一个控件加上下文菜单(ContextMenu)Creating a ContextMenu on a View

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：

Java代码

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;  
          }  
     }  
}