ขอความช่วยเหลือ!! select ข้อมูลจาก database แล้วข้อมูลไม่ขึ้นที่ Gridview

<p>
        <asp:GridView ID="GridView1" runat="server" ShowFooter="true" DataKeyNames="id" CellPadding="0" BorderWidth="1px" 
            ForeColor="#333333" AutoGenerateColumns="false" AllowSorting="true" PageSize="30" AllowPaging="true"
             OnPageIndexChanging="GridView1_PageIndexChanging">

            <Columns>
                <asp:BoundField DataField="" InsertVisible="False" ReadOnly="True" ItemStyle-Width="50px">
                    <ItemStyle Width="50px"></ItemStyle>
                </asp:BoundField>

                <asp:TemplateField ItemStyle-Width="200px" HeaderStyle-Height="30" Visible="false" >
                    <ItemTemplate>
                        <asp:Label ID="id" runat="server" Text='<%# Eval("id")%>'></asp:Label>
                    </ItemTemplate>               
                    <HeaderStyle Height="30px"></HeaderStyle>
                    <ItemStyle Width="200px"></ItemStyle>    
                </asp:TemplateField>

                <asp:TemplateField ItemStyle-Width="200px" HeaderText="รหัสวัตถุดิบ" HeaderStyle-Height="30">
                    <InsertItemTemplate>
                        <asp:Label ID="lbl_material" runat="server" Text='<%#Eval("num_material")%>'></asp:Label>
                    </InsertItemTemplate>
                    <HeaderStyle Height="30px"></HeaderStyle>
                    <ItemStyle Width="200px"></ItemStyle>
                </asp:TemplateField>

                <asp:TemplateField ItemStyle-Width="200px" HeaderText="วัตถุดิบ" HeaderStyle-Height="30">
                    <InsertItemTemplate>
                        <asp:Label ID="lbl_material_etc" runat="server" Text='<%#Eval("name_material")%>'></asp:Label>
                    </InsertItemTemplate>
                    <HeaderStyle Height="30px"></HeaderStyle>
                    <ItemStyle Width="200px"></ItemStyle>
                </asp:TemplateField>

                <asp:TemplateField ItemStyle-Width="200px" HeaderText="จุดที่พบปัญหา" HeaderStyle-Height="30">
                    <InsertItemTemplate>
                        <asp:Label ID="lbl_area" runat="server" Text='<%#Eval("area")%>'></asp:Label>
                    </InsertItemTemplate>
                    <HeaderStyle Height="30px"></HeaderStyle>
                    <ItemStyle Width="200px"></ItemStyle>
                </asp:TemplateField>

                <asp:TemplateField ItemStyle-Width="200px" HeaderText="วันที่รับเข้า" HeaderStyle-Height="30">
                    <InsertItemTemplate>
                        <asp:Label ID="lbl_dateInput_in" runat="server" Text='<%#Eval("input_dt")%>'></asp:Label>
                    </InsertItemTemplate>
                    <HeaderStyle Height="30px"></HeaderStyle>
                    <ItemStyle Width="200px"></ItemStyle>
                </asp:TemplateField>

                <asp:TemplateField ItemStyle-Width="50px" HeaderText="Lot." HeaderStyle-Height="30">
                    <InsertItemTemplate>
                        <asp:Label ID="lbl_lot" runat="server" Text='<%#Eval("lot")%>'></asp:Label>
                    </InsertItemTemplate>
                    <HeaderStyle Height="30px"></HeaderStyle>
                    <ItemStyle Width="50px"></ItemStyle>
                </asp:TemplateField>

                <asp:TemplateField ItemStyle-Width="200px" HeaderText="ลูกค้า/Supplier" HeaderStyle-Height="30">
                    <InsertItemTemplate>
                        <asp:Label ID="lbl_sup" runat="server" Text='<%#Eval("supplier")%>'></asp:Label>
                    </InsertItemTemplate>
                    <HeaderStyle Height="30px"></HeaderStyle>
                    <ItemStyle Width="200px"></ItemStyle>
                </asp:TemplateField>

                <asp:TemplateField ItemStyle-Width="250px" HeaderText="สิ่งแปลกปลอมที่พบ" HeaderStyle-Height="30">
                    <InsertItemTemplate>
                        <asp:Label ID="lbl_obj" runat="server" Text='<%#Eval("obj")%>'></asp:Label>
                    </InsertItemTemplate>
                    <HeaderStyle Height="30px"></HeaderStyle>
                    <ItemStyle Width="250px"></ItemStyle>
                </asp:TemplateField>

                <asp:TemplateField ItemStyle-Width="100px" HeaderText="Corective" HeaderStyle-Height="30">
                    <InsertItemTemplate>
                        <asp:LinkButton ID="lnkCorective" runat="server" Text="Click" CommandName="Click" ToolTip="Click" CommandArgument=''>Click!</asp:LinkButton>
                    </InsertItemTemplate>
                    <HeaderStyle Width="50px"></HeaderStyle>
                    <ItemStyle HorizontalAlign="Center" />
                </asp:TemplateField>

            </Columns>

            <HeaderStyle BackColor="#71D149" />
            <PagerSettings PageButtonCount="5" />
            <RowStyle HorizontalAlign="Center" />
        </asp:GridView>
    </p>

Imports System
Imports System.Data
Imports System.Data.SqlClient

Partial Class _Default
    Inherits System.Web.UI.Page
    Dim strConnString As String = ConfigurationManager.ConnectionStrings("ConnString").ConnectionString

    Dim Conn As SqlConnection
    Dim Cmd As SqlCommand
    Dim sql As String
    Dim reader As SqlDataReader

    Sub setYear()
        System.Threading.Thread.CurrentThread.CurrentCulture = System.Globalization.CultureInfo.CreateSpecificCulture("en-US")
        System.Threading.Thread.CurrentThread.CurrentUICulture = System.Threading.Thread.CurrentThread.CurrentCulture
    End Sub

    Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
        If Not IsPostBack Then
            bindata()
        End If
        setYear()
    End Sub

    Sub bindata()
        Dim con As New SqlConnection(strConnString)
        Dim dt As New DataTable()
        Dim query As String = " SELECT id, num_material, name_material, area, input_dt, lot, supplier, obj FROM obj_tbl "
        Dim objda As New SqlDataAdapter(query, con)
        con.Open()
        objda.Fill(dt)
        objda = Nothing
        If dt.Rows.Count > 0 Then
            GridView1.DataSource = dt
            GridView1.DataBind()
        End If
        con.Close()
    End Sub

    Protected Sub GridView1_PageIndexChanging(sender As Object, e As GridViewPageEventArgs)
        GridView1.PageIndex = e.NewPageIndex
        bindata()
    End Sub
End Class