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>
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; } } }