/* * 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; import android.content.Context; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.PopupMenu; import android.widget.PopupMenu.OnMenuItemClickListener; import net.micode.notes.R; public class DropdownMenu {//声明一个下拉菜单类 private Button mButton;/*按钮控件、下拉菜单按键、菜单*/ private PopupMenu mPopupMenu; private Menu mMenu; public DropdownMenu(Context context, Button button, int menuId) {//首先是公有类DropdownMenu的私有数据成员申明,其中包括了对象按钮mButton, // 菜单对象mMenu和弹出菜单控件对象mPopupMenu mButton = button; //设置下拉菜单的背景 mButton.setBackgroundResource(R.drawable.dropdown_icon); // mPopupMenu = new PopupMenu(context, mButton);//初始化下拉菜单由mButton触发 mMenu = mPopupMenu.getMenu();//将menuId指向的菜单项目添加到mMenu中 mPopupMenu.getMenuInflater().inflate(menuId, mMenu); mButton.setOnClickListener(new OnClickListener() { public void onClick(View v) { mPopupMenu.show(); } }); } public void setOnDropdownMenuItemClickListener(OnMenuItemClickListener listener) {//方法:对非空的菜单的具体条目设置监听。 if (mPopupMenu != null) { mPopupMenu.setOnMenuItemClickListener(listener); } } public MenuItem findItem(int id) {//对于菜单选项的初始化,根据索引搜索菜单需要的选项 return mMenu.findItem(id); } public void setTitle(CharSequence title) {//根据索引搜索菜单需要的选项 mButton.setText(title); } }