รับค่ารหัสกิจกรรมจากDropdownListในPage1 แล้วให้แสดงรายชื่อนักศึกษาที่เข้าร่วมกิจกรรมนั้นในPage2 (asp.net + ฐานข้อมูลSQLServer2005)

<%@ Import Namespace="System.Data"%> 
<%@ Import Namespace="System.Data.SqlClient"%> 
<%@ Page Language="VB" %> 
<script runat="server"> 
    
    Dim objConn As SqlConnection
    Dim objCmd As SqlCommand
    Dim dtReader As SqlDataReader
    Dim strConnString, strSQL As String
    
    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)
        strConnString = "Data Source=.\SQLEXPRESS;AttachDbFilename=D:\Project\web site\App_Data\Activity.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True"
        objConn = New SqlConnection(strConnString)
        objConn.Open()
        
        'Dim empid As String = Request.QueryString("emp")
        'Me.lblempid.Text = empid
        Dim acid As String = Request.QueryString("acid")
        Me.lblacid.Text = acid

        Dim dtAdapter As SqlDataAdapter
        Dim dt1 As New DataTable
        
        strSQL = "SELECT * FROM Calendar_Activity WHERE AcID = '" & Me.lblacid.Text & "'"
        dtAdapter = New SqlDataAdapter(strSQL, objConn)
        dtAdapter.Fill(dt1)
        
        If dt1.Rows.Count > 0 Then
            Me.lblname.Text = dt1.Rows(0)("AcName")
            Me.lbldate.Text = dt1.Rows(0)("AcDate")
            Me.lblmonth.Text = dt1.Rows(0)("AcMonth")
            Me.lblyear.Text = dt1.Rows(0)("AcYear")
            Me.lblterm.Text = dt1.Rows(0)("Term")
            Me.lbledu.Text = dt1.Rows(0)("Eduyear")
        End If
        
        If Not Page.IsPostBack() Then
            BindData()
        End If
        
    End Sub
    
    Sub BindData()
        Dim objConn As New SqlConnection
        Dim objCmd As New SqlCommand
        Dim dtAdapter As New SqlDataAdapter
        Dim ds As New DataSet
        Dim strConnString, strSQL As String
        Dim acid As String = Request.QueryString("acid")
        Me.lblacid.Text = acid
        
        strConnString = "Data Source=.\SQLEXPRESS;AttachDbFilename=D:\Project\web site\App_Data\Activity.mdf;Integrated Security=True;Max Pool Size=5000;Connect Timeout=30;User Instance=True"
        strSQL = "SELECT Student.StdID,StdFName,StdLName,Gender,Faculty,HouseNo,SubDistrict,District,Province,ZipCode,Email,Phone FROM Student,Calendar_Activity ,Do_Activitys WHERE(Do_Activitys.StdID = Student.StdID) AND Do_Activitys.AcID = '" & Me.lblacid.Text & "'"
       
        objConn = New SqlConnection(strConnString)
        
        With objCmd
            .Connection = objConn
            .CommandText = strSQL
            .CommandType = CommandType.Text
        End With
        dtAdapter.SelectCommand = objCmd

        dtAdapter.Fill(ds)
        
        '*** BindData to GridView ***'
        myGridView.DataSource = ds
        myGridView.DataBind()

        dtAdapter = Nothing
        'objConn.Close()
        'objConn = Nothing
    End Sub
    
    Sub myGridView_RowDataBound(ByVal sender As Object, ByVal e As GridViewRowEventArgs)
        '*** StdID ***'
        Dim stdid As Label = CType(e.Row.FindControl("StdID"), Label)
        If Not IsNothing(stdid) Then
            stdid.Text = e.Row.DataItem("StdID")
        End If
        '*** StdFName ***'
        Dim stdfname As Label = CType(e.Row.FindControl("StdFName"), Label)
        If Not IsNothing(stdfname) Then
            stdfname.Text = e.Row.DataItem("StdFName")
        End If
        '*** StdLName ***'
        Dim stdlname As Label = CType(e.Row.FindControl("StdLName"), Label)
        If Not IsNothing(stdlname) Then
            stdlname.Text = e.Row.DataItem("StdLName")
        End If
        '*** Gender ***'
        Dim gender As Label = CType(e.Row.FindControl("Gender"), Label)
        If Not IsNothing(gender) Then
            gender.Text = e.Row.DataItem("Gender")
        End If
        '*** Faculty ***'
        Dim faculty As Label = CType(e.Row.FindControl("Faculty"), Label)
        If Not IsNothing(faculty) Then
            faculty.Text = e.Row.DataItem("Faculty")
        End If
        '*** HouseNo ***'
        Dim houseno As Label = CType(e.Row.FindControl("HouseNo"), Label)
        If Not IsNothing(houseno) Then
            houseno.Text = e.Row.DataItem("HouseNo")
        End If
        '*** SubDistrict ***'
        Dim subdistrict As Label = CType(e.Row.FindControl("SubDistrict"), Label)
        If Not IsNothing(subdistrict) Then
            subdistrict.Text = e.Row.DataItem("SubDistrict")
        End If
        '*** District ***'
        Dim district As Label = CType(e.Row.FindControl("District"), Label)
        If Not IsNothing(district) Then
            district.Text = e.Row.DataItem("District")
        End If
        '*** Province ***'
        Dim province As Label = CType(e.Row.FindControl("Province"), Label)
        If Not IsNothing(province) Then
            province.Text = e.Row.DataItem("Province")
        End If
        '*** ZipCode ***'
        Dim zipcode As Label = CType(e.Row.FindControl("ZipCode"), Label)
        If Not IsNothing(zipcode) Then
            zipcode.Text = e.Row.DataItem("ZipCode")
        End If
        '*** Email ***'
        Dim email As Label = CType(e.Row.FindControl("Email"), Label)
        If Not IsNothing(email) Then
            email.Text = e.Row.DataItem("Email")
        End If
        '*** Phone ***'
        Dim phone As Label = CType(e.Row.FindControl("Phone"), Label)
        If Not IsNothing(phone) Then
            phone.Text = e.Row.DataItem("Phone")
        End If
    End Sub
    
    Sub ShowPageCommand(ByVal s As Object, ByVal e As GridViewPageEventArgs)
        myGridView.PageIndex = e.NewPageIndex
        BindData()
    End Sub

    Protected Sub btn_close_Click(ByVal sender As Object, ByVal e As System.EventArgs)
        Dim empid As String = Request.QueryString("emp")
        Response.Redirect("employee_search_acid.aspx?def=" & empid)
    End Sub
</script>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>Untitled Page</title>
    <style type="text/css">
        #form1
        {
            width: 1302px;
        }
        .newStyle1
        {
            background-color: #FFFF99;
            border: thin solid #800080;
        }
        </style>
</head>
<body bgcolor="White">
    <form id="form1" runat="server">
    <asp:Label ID="lblempid" runat="server"></asp:Label>
    <b>
    <br />
    </b>
    รหัสกิจกรรม :<b>&nbsp;
    <asp:Label ID="lblacid" runat="server" Font-Size="14pt"></asp:Label>
    &nbsp;&nbsp; 
    </b>
        ชื่อกิจกรรม :<b>&nbsp;
    <asp:Label ID="lblname" runat="server" Font-Size="14pt"></asp:Label>
    <br />
    </b>
    วันที่ดำเนินกิจกรรม :&nbsp;<b>
    <asp:Label ID="lbldate" runat="server" Font-Size="14pt"></asp:Label>
&nbsp;
    <asp:Label ID="lblmonth" runat="server" Font-Size="14pt"></asp:Label>
&nbsp;
    <asp:Label ID="lblyear" runat="server" Font-Size="14pt"></asp:Label>
    <br />
    </b>
    ภาคเรียนที่ :&nbsp;<b>
    <asp:Label ID="lblterm" runat="server" Font-Size="14pt"></asp:Label>
&nbsp;&nbsp;&nbsp; 
    </b>
    ปีการศึกษา&nbsp;:<b>
    <asp:Label ID="lbledu" runat="server" Font-Size="14pt"></asp:Label>
    <br />
    </b>
    &nbsp;&nbsp;&nbsp;&nbsp;
    <br />
&nbsp;<br />
    <asp:GridView ID="myGridView" runat="server" BorderColor="Black" Width="1300px">
        <FooterStyle HorizontalAlign="Center" VerticalAlign="Middle" />
        <RowStyle BorderColor="Black" Font-Size="14pt" HorizontalAlign="Center" 
            VerticalAlign="Middle" />
        <PagerStyle HorizontalAlign="Center" VerticalAlign="Middle" />
        <SelectedRowStyle BorderColor="Black" HorizontalAlign="Center" 
            VerticalAlign="Middle" />
        <HeaderStyle HorizontalAlign="Center" VerticalAlign="Middle" />
        <EmptyDataRowStyle HorizontalAlign="Center" VerticalAlign="Middle" />
        <Columns>
        <asp:TemplateField HeaderText="#" >
        <ItemTemplate>
                <%# Container.DataItemIndex + 1 %>
        </ItemTemplate>
            <ControlStyle Width="40px" />
            <FooterStyle HorizontalAlign="Center" VerticalAlign="Middle" Width="40px" />
            <HeaderStyle HorizontalAlign="Center" VerticalAlign="Middle" Width="40px" />
            <ItemStyle HorizontalAlign="Center" VerticalAlign="Middle" Width="40px" />
        </asp:TemplateField>
        </Columns>
        <EditRowStyle HorizontalAlign="Center" VerticalAlign="Middle" />
    </asp:GridView>
    <br />
    <br />
    <asp:Button ID="btn_close" runat="server" Font-Size="Medium" Text="กลับ" 
        Width="70px" onclick="btn_close_Click" />
    <br />
</form>
    </body>
</html>