error ส่วนที่คอมเม้นไว้อะคะ error ' Dim objDR As SqlDataReader รบกวนผู้รูหน่อยคะ

Sub BindData()
        Dim strConn As String = "Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\Rescuedb.mdf;Integrated Security=True;User Instance=True"
        Dim objConn As New SqlConnection(strConn)
        objConn.Open()
        Dim cmdSQL As String = "SELECT StaffID+''+StaffName+''+StaffAge+''+StaffP As StaffData" & "FROM dbo.Staff "
        Dim Cmd As New SqlCommand(cmdSQL, objConn)

        ' Dim objDR As SqlDataReader
        'objDR = Cmd.ExecuteReader(System.Data.CommandBehavior.CloseConnection)
        ' lstStaff.DataSource = objDR

        lstStaff.DataValueField = "StaffID"
        lstStaff.DataTextField = "StaffData"
        lstStaff.DataBind()
        If lstStaff.Rows > 0 Then
            lstStaff.SelectedIndex = 0
        End If
        lstStaff.Focus()
        objConn.Close()
    End Sub

Imports System.Data
Imports System.Data.SqlClient

Public Class MStaff
    Inherits System.Web.UI.Page

   

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
        If Not IsPostBack Then
            TxtSurname.Text = ""
            Txtage.Text = ""
            TxtP.Text = ""
            TxtSurname.Focus()
        End If
        BSDel.Attributes.Add("onclick", "if(!window.confirm('Are you sure delete record??'))" & "return false;")
        If Not IsPostBack Then
            BindData()
        End If

    End Sub

    Protected Sub BSDel_Click(ByVal sender As Object, ByVal e As EventArgs) Handles BSDel.Click
        'Delete Data
        Dim strConn As String = "Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\Rescuedb.mdf;Integrated Security=True;User Instance=True"
        Dim objConn As New SqlConnection(strConn)
        objConn.Open()
        Dim cmdSQL As String = "DELETE FROM dbo.Staff" & "WHERE StaffID=@StaffID"
        Dim Cmd As New SqlCommand(cmdSQL, objConn)
        Cmd.Parameters.Add(New SqlParameter("@StaffID", lblStaffID.Text))
        Cmd.ExecuteNonQuery()
        objConn.Close()
        BindData()
        lstStaff.Focus()
        lblMessage.Text = "Successfully Delete:" & TxtSurname.Text & " " & Txtage.Text & " " & TxtP.Text
        TxtSurname.Enabled = False
        Txtage.Enabled = False
        TxtP.Enabled = False
        BSUpdate.Visible = False
        BSDel.Visible = False
    End Sub


    Protected Sub BSAdd_Click(ByVal sender As Object, ByVal e As EventArgs) Handles BSAdd.Click
        lblErrorSurname.Visible = False
        lblErrorage.Visible = False
        lblErrorP.Visible = False
        'Check Error input
        If TxtSurname.Text = "" Then
            lblErrorSurname.Visible = True
            lblError.Text = "Please Enter Name"
            TxtSurname.Focus()
            Return
        End If
        If Txtage.Text = "" Then
            lblErrorage.Visible = True
            lblError.Text = "Please Enter age"
            Txtage.Focus()
            Return
        End If
        If TxtP.Text = "" Then
            lblErrorP.Visible = True
            lblError.Text = "Please Enter P"
            TxtP.Focus()
            Return
        End If
        'Insert Data into SQL Server 2008
        Dim strConn As String = "Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\Rescuedb.mdf;Integrated Security=True;User Instance=True"
        Dim objConn As New SqlConnection(strConn)
        objConn.Open()
        Dim cmdSQL As String = "INSERT INTO dbo.Staff" & "(StaffName,StaffAge,StaffP)" & "VALUES(@StaffName,@StaffAge,@StaffP)"
        Dim Cmd As New SqlCommand(cmdSQL, objConn)
        Cmd.Parameters.Add(New SqlParameter("@StaffName", TxtSurname.Text))
        Cmd.Parameters.Add(New SqlParameter("@StaffAge", Txtage.Text))
        Cmd.Parameters.Add(New SqlParameter("@StaffP", TxtP.Text))
        Cmd.ExecuteNonQuery()
        objConn.Close()
        lblError.Text = "Successfully Insert:" & TxtSurname.Text & " " & Txtage.Text & " " & TxtP.Text
        TxtSurname.Text = ""
        Txtage.Text = ""
        TxtP.Text = ""
        TxtSurname.Focus()

    End Sub

   
  
   

    Protected Sub BSUpdate_Click(ByVal sender As Object, ByVal e As EventArgs) Handles BSUpdate.Click
       
        'Check Error input
        lblMessage.Text = ""
        lblErrorSurname.Visible = False
        lblErrorage.Visible = False
        lblErrorP.Visible = False
        If TxtSurname.Text = "" Then
            lblErrorSurname.Visible = True
            lblError.Text = "Please Enter Name"
            TxtSurname.Focus()
            Return
        End If
        If Txtage.Text = "" Then
            lblErrorage.Visible = True
            lblError.Text = "Please Enter age"
            Txtage.Focus()
            Return
        End If
        If TxtP.Text = "" Then
            lblErrorP.Visible = True
            lblError.Text = "Please Enter P"
            TxtP.Focus()
            Return
        End If
        'Update Data
        Dim strConn As String = "Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\Rescuedb.mdf;Integrated Security=True;User Instance=True"
        Dim objConn As New SqlConnection(strConn)
        objConn.Open()
        Dim cmdSQL As String = "UPDATE dbo.Staff" & "SET StaffName=@StaffName,StaffAge=@StaffAge,StaffP=@StaffP " & "WHERE StaffID=@StaffID"
        Dim Cmd As New SqlCommand(cmdSQL, objConn)
        Cmd.Parameters.Add(New SqlParameter("@StaffID", lblStaffID.Text))
        Cmd.Parameters.Add(New SqlParameter("@StaffName", TxtSurname.Text))
        Cmd.Parameters.Add(New SqlParameter("@StaffAge", Txtage.Text))
        Cmd.Parameters.Add(New SqlParameter("@StaffP", TxtP.Text))
        Cmd.ExecuteNonQuery()
        objConn.Close()
        BindData()
        lstStaff.SelectedIndex = lstStaff.Items.IndexOf(lstStaff.Items.FindByValue(lblStaffID.Text))
        lstStaff.Focus()
        lblMessage.Text = "Successfully Update:" & TxtSurname.Text & " " & Txtage.Text & " " & TxtP.Text
        TxtSurname.Enabled = False
        Txtage.Enabled = False
        TxtP.Enabled = False
        BSUpdate.Visible = False
        BSDel.Visible = False      
    End Sub


    Protected Sub BSEdit_Click(ByVal sender As Object, ByVal e As EventArgs) Handles BSEdit.Click
        If lstStaff.SelectedIndex < 0 Then
            lblMessage.Text = "Please Select Staff"
            Return
        End If
        Dim strConn As String = "Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\Rescuedb.mdf;Integrated Security=True;User Instance=True"
        Dim objConn As New SqlConnection(strConn)
        objConn.Open()
        Dim cmdSQL As String = "SELECT StaffID,StaffName,StaffAge,StaffP" & "FROM dbo.Staff Where StaffID =" & lstStaff.SelectedItem.Value
        Dim Cmd As New SqlCommand(cmdSQL, objConn)
        Dim objDR As SqlDataReader
        objDR = Cmd.ExecuteReader(System.Data.CommandBehavior.CloseConnection)
        While objDR.Read()
            lblStaffID.Text = objDR("StaffID")
            TxtSurname.Text = objDR("StaffName")
            Txtage.Text = objDR("StaffAge")
            TxtP.Text = objDR("StaffP")
        End While
        TxtSurname.Enabled = True
        Txtage.Enabled = True
        TxtP.Enabled = True
        BSUpdate.Visible = True
        BSDel.Visible = True
        lblMessage.Text = ""
        lblErrorSurname.Visible = False
        lblErrorage.Visible = False
        lblErrorP.Visible = False
    End Sub



   

    Sub BindData()
        Dim strConn As String = "Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\Rescuedb.mdf;Integrated Security=True;User Instance=True"
        Dim objConn As New SqlConnection(strConn)
        objConn.Open()
        Dim cmdSQL As String = "SELECT StaffID+''+StaffName+''+StaffAge+''+StaffP As StaffData" & "FROM dbo.Staff "
        Dim Cmd As New SqlCommand(cmdSQL, objConn)
        ' Dim objDR As SqlDataReader
        'objDR = Cmd.ExecuteReader(System.Data.CommandBehavior.CloseConnection)
        ' lstStaff.DataSource = objDR
        lstStaff.DataValueField = "StaffID"
        lstStaff.DataTextField = "StaffData"
        lstStaff.DataBind()
        If lstStaff.Rows > 0 Then
            lstStaff.SelectedIndex = 0
        End If
        lstStaff.Focus()
        objConn.Close()
    End Sub

End Class