Android编程实现二级下拉菜单及快速搜索的方法

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>
 <LinearLayout
  android: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 >
 <TextView
  android:id="@+id/group" >
 </TextView>
 <ImageView
  android:id="@+id/tubiao">
 </ImageView>
</LinearLayout>

（3）二级菜单栏样式

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout >
 <TextView
  android: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 {
  @Override
  public int getGroupCount() {
   return fatherList.size();
  }
  @Override
  public int getChildrenCount(int groupPosition) {
   return childList.get(groupPosition).size();
  }
  @Override
  public Object getGroup(int groupPosition) {
   return fatherList.get(groupPosition).getValue();
  }
  @Override
  public Object getChild(int groupPosition, int childPosition) {
   return childList.get(groupPosition).get(childPosition).getValue();
  }
  @Override
  public long getGroupId(int groupPosition) {
   return groupPosition;
  }
  @Override
  public long getChildId(int groupPosition, int childPosition) {
   return childPosition;
  }
  @Override
  public 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);
   else
    gImg.setBackgroundResource(R.drawable.mm_submenu_normal);
   return view;
  }
  @Override
  public 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;
  }
  @Override
  public boolean hasStableIds() {
   return true;
  }
  @Override
  public 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。