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。