/* * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net) * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package net.micode.notes.ui;//导入ui包 import android.content.Context;//引入需要使用的Context、Menu等包 import android.view.Menu; import android.view.MenuItem;//菜单条款 import android.view.View; import android.view.View.OnClickListener;//监听点击 import android.widget.Button;//导入按钮工具 import android.widget.PopupMenu;//弹出菜单 import android.widget.PopupMenu.OnMenuItemClickListener;//菜单点击监听器 import net.micode.notes.R; public class DropdownMenu {//声明一个下拉菜单 private Button mButton;//定义按钮控件 private PopupMenu mPopupMenu;//定义弹出式菜单 private Menu mMenu;//定义菜单 public DropdownMenu(Context context, Button button, int menuId) {//设置显示一个菜单 mButton = button;//设置按钮样式 mButton.setBackgroundResource(R.drawable.dropdown_icon);//设置其背景资源为下拉菜单的图标 mPopupMenu = new PopupMenu(context, mButton);//实例化一个弹出式菜单 mMenu = mPopupMenu.getMenu();//获得弹出式菜单的菜单项 mPopupMenu.getMenuInflater().inflate(menuId, mMenu);//获得弹出式菜单的菜单项 mButton.setOnClickListener(new OnClickListener() {//当我们点击mButton时,会弹出菜单 public void onClick(View v) { mPopupMenu.show(); }//设点击显示菜单 }); } public void setOnDropdownMenuItemClickListener(OnMenuItemClickListener listener) {//置下拉菜单的点击监听方法 if (mPopupMenu != null) { mPopupMenu.setOnMenuItemClickListener(listener);//对非空的菜单的具体条目设置监听 } } public MenuItem findItem(int id) { return mMenu.findItem(id); }//对于菜单选项的初始化,根据索引搜索菜单需要的选项 public void setTitle(CharSequence title) { mButton.setText(title); }//根据索引搜索菜单需要的选项 }