本文实例讲述了Android编程实现二级下拉菜单及快速搜索的方法。分享给大家供大家参考,具体如下:
一、我们要做什么?

上面有个搜索框,下面是一个二级下拉菜单。

输入查询内容,下面列表将显示查询结果。
二、界面设计
(1)这是主框架(部分属性已经省去,请看源码),从上至下分别是文本框,列表,二级列表。
<?xml version="1.0" encoding="utf-8"?><LinearLayout> <LinearLayoutandroid:id="@+id/city_middle"><EditText android:id="@+id/txtfind" android:hint="请输入" ></EditText><ListView android:id="@+id/listfind" ></ListView><ExpandableListView android:id="@+id/exList" /> </LinearLayout></LinearLayout>
(2)一级菜单栏样式,图片将区别是否展开
<?xml version="1.0" encoding="utf-8"?><LinearLayout > <TextViewandroid:id="@+id/group" > </TextView> <ImageViewandroid:id="@+id/tubiao"> </ImageView></LinearLayout>
(3)二级菜单栏样式
<?xml version="1.0" encoding="utf-8"?><LinearLayout > <TextViewandroid:id="@+id/child"> </TextView></LinearLayout>
三、代码设计
(1) 定义菜单对应数据
public static List<BasicNameValuePair> fatherList = new ArrayList<BasicNameValuePair>();public static List<List<BasicNameValuePair>> childList = new ArrayList<List<BasicNameValuePair>>();
生成测试数据
for (int i = 0; i < 20; i++) { fatherList.add(new BasicNameValuePair("father" + i, "father" + i)); List<BasicNameValuePair> cList = new ArrayList<BasicNameValuePair>(); for (int j = 0; j < 5; j++) {cList.add(new BasicNameValuePair("child" + i + ":" + j, "child"+ i + ":" + j)); } childList.add(cList);}
(2)定义列表适配器
protected class ListAdapter extends BaseAdapter {private LayoutInflater mInflater;//查询结果列表private List<BasicNameValuePair> list = new ArrayList<BasicNameValuePair>();public ListAdapter(Context context, String strin) { mInflater = LayoutInflater.from(context); //查询匹配 for (int i = 0; i < childList.size(); i++) {for (int j = 0; j < childList.get(i).size(); j++) { String tmp = childList.get(i).get(j).getValue(); if (tmp.indexOf(strin) >= 0) {list.add(new BasicNameValuePair(childList.get(i).get(j).getName(), tmp)); }} }}public int getCount() { return list.size();}public Object getItem(int position) { return position;}public long getItemId(int position) { return position;}public View getView(final int position, View convertView,ViewGroup parent) { convertView = mInflater.inflate(R.layout.child, null); TextView title = (TextView) convertView.findViewById(R.id.child); title.setText(list.get(position).getValue()); return convertView;} }
初始化列表,默认为隐藏
list = (ListView) findViewById(R.id.listfind);list.setVisibility(View.GONE);
(3)定义二级列表适配器
protected class ExAdapter extends BaseExpandableListAdapter {@Overridepublic int getGroupCount() { return fatherList.size();}@Overridepublic int getChildrenCount(int groupPosition) { return childList.get(groupPosition).size();}@Overridepublic Object getGroup(int groupPosition) { return fatherList.get(groupPosition).getValue();}@Overridepublic Object getChild(int groupPosition, int childPosition) { return childList.get(groupPosition).get(childPosition).getValue();}@Overridepublic long getGroupId(int groupPosition) { return groupPosition;}@Overridepublic long getChildId(int groupPosition, int childPosition) { return childPosition;}@Overridepublic View getGroupView(int groupPosition, boolean isExpanded,View convertView, ViewGroup parent) { View view = convertView; if (view == null) {LayoutInflater inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);view = inflater.inflate(R.layout.group, null); } TextView t = (TextView) view.findViewById(R.id.group); t.setText(fatherList.get(groupPosition).getValue()); //展开,改变图片 ImageView gImg = (ImageView) view.findViewById(R.id.tubiao); if (isExpanded)gImg.setBackgroundResource(R.drawable.mm_submenu_down_normal); elsegImg.setBackgroundResource(R.drawable.mm_submenu_normal); return view;}@Overridepublic View getChildView(int groupPosition, int childPosition,boolean isLastChild, View convertView, ViewGroup parent) { View view = convertView; if (view == null) {LayoutInflater inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);view = inflater.inflate(R.layout.child, null); } TextView t = (TextView) view.findViewById(R.id.child); t.setText(childList.get(groupPosition).get(childPosition) .getValue()); return view;}@Overridepublic boolean hasStableIds() { return true;}@Overridepublic boolean isChildSelectable(int groupPosition, int childPosition) { return true;}}
初始化二级菜单
exList = (ExpandableListView) findViewById(R.id.exList);exList.setAdapter(new ExAdapter());exList.setGroupIndicator(null);exList.setDivider(null);
(4)搜索事件,输入改变即触发
txtFind = (EditText) findViewById(R.id.txtfind);txtFind.addTextChangedListener(new TextWatcher() { @Override public void beforeTextChanged(CharSequence s, int start, int count, int after) { } @Override public void onTextChanged(CharSequence s, int start, int before, int count) { } @Override public void afterTextChanged(Editable s) {if (s != null && !s.toString().equals("")) { list.setAdapter(new ListAdapter(DWinterDemoActivity.this, s .toString())); list.setVisibility(View.VISIBLE); exList.setVisibility(View.GONE);} else { list.setVisibility(View.GONE); exList.setVisibility(View.VISIBLE);} }});
(5)去除焦点自动弹出输入
getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);
希望本文所述对大家Android程序设计有所帮助。