动态增加控件。转

<% @ Page Language = " C# "   %>
< script runat = " server " >
protected   void  Page_Load( object  sender, EventArgs e)
{
 if(!IsPostBack) 
 ViewState["Count"]=0;
 else 
 for(int i=1;i<=(int)ViewState["Count"];i++)
 {
 addproduct(i.ToString());
 }
}
  void  addproduct( string  num)
  {
 LiteralControl mylabel;
 TextBox mybox = new TextBox();
 mylabel = new LiteralControl();
 mylabel.Text = "<p>" + "产品:" + num;
 PlaceHolder1.Controls.Add(mylabel);
 mybox = new TextBox();
 mybox.ID = "txtProduct" + num;
 PlaceHolder1.Controls.Add(mybox);
 }
protected   void  add_btn( object  sender, EventArgs e)
{
 int count =(int)ViewState["Count"];
 count++;
 ViewState["Count"] = count;
 addproduct(ViewState["Count"].ToString());
}
</ script >
< html xmlns = " http://www.w3.org/1999/xhtml "   >
< head runat = " server " >
  < title > 动态添加控件 </ title >
</ head >
< body style = " font-size: 12px; " >
  < form id = " form1 "  runat = " server " >
  < div >
  < asp:PlaceHolder ID = " PlaceHolder1 "  runat = " server " ></ asp:PlaceHolder >
  < br  />
  < asp:Button ID = " Button1 "  runat = " server "  Text = " 增加 "  OnClick = " add_btn "   />
  </ form >
</ body >
</ html >

  Server.MapPath所在命名空间
 System.Web.HttpContext.Current. Server.MapPath