求解释下搜索功能代码？
搜索是通过一个自定义控件来实现的src.ascx.cs
 protected void Button1_Click(object sender, EventArgs e)
  {
  string whe = Server.HtmlEncode(scrtb.Text.ToString());
  switch (scrddl.SelectedValue)
  {
  case "name":
  Response.Redirect("screch.aspx?sql=name&key="+whe);
  break;
  case "title":
  Response.Redirect("screch.aspx?sql=title&key=" + whe);
  break;
  case "concent":
  Response.Redirect("screch.aspx?sql=concent&key=" + whe);
  break;
  }
  }

搜索结果页放了个gridview
 protected void Page_Load(object sender, EventArgs e)
  {
  if (!IsPostBack)
  {
  fill();
  }
  }
  public void fill()
  {
  string sql = Request.QueryString["sql"];
  string whe = Request.QueryString["key"];

  string que = "";
  switch (sql)
  {
  case "name":
  　que += ("select * from guest where name like '%" + whe + "%' order by id Desc");
  break;
  case "title":
  que += ("select * from guest where title like '%" + whe + "%' order by id Desc");
  break;
  case "concent":
  que += ("select * from guest where concent like '%" + whe + "%' order by id Desc");
  break;
  }

  if ((odb.ds(que)).Rows.Count <= 0)
  {
  Response.Write("未找到你想要的，<a href=javascript:history.back()>返回</a>重新来过吧！");
  }
  else
  {
  GridView1.DataSource = odb.ds(que);//odb是数据库链接类
  GridView1.DataBind();
  }
   
  }

------解决方案--------------------
protected void Button1_Click(object sender, EventArgs e) 
{ 
string whe = Server.HtmlEncode(scrtb.Text.ToString());//获取搜索的关键字 
switch (scrddl.SelectedValue) //选择搜索的选项:名称(name),标题(title),内容(content)
{ 
case "name": 
Response.Redirect("screch.aspx?sql=name&key="+whe); 
break; 
case "title": 
Response.Redirect("screch.aspx?sql=title&key=" + whe); 
break; 
case "concent": 
Response.Redirect("screch.aspx?sql=concent&key=" + whe); 
break; 
} //选择好后,跳转到screch.aspx页面,传递sql,key参数
} 
--------------------------------
protected void Page_Load(object sender, EventArgs e) 
{ 
if (!IsPostBack) 
{ 
fill(); //显示查找的数据
} 
} 
public void fill() 
{ 
string sql = Request.QueryString["sql"]; 
string whe = Request.QueryString["key"]; //获取传递的两个参数,sql和key

string que = ""; 
switch (sql)//跟据查找的类型写出查询语句,这里的查询是模糊查询并且以id字段进行降序排列