troubleshooting Question

How to correct this error in Vb.Net.

Avatar of searchsanjaysharma
searchsanjaysharma asked on
Visual Basic.NET
13 Comments1 Solution314 ViewsLast Modified:
I have a put a time on Vb.NEt windows form, which fethches the data every 15 seconds. but the following error in starting.
Object reference not set to an instance of an object.

Timer1_Tick
Interval - 15000

Try
            If (txtauin.Text.Trim() <> "") Then
                con = New SqlConnection("Data Source=172.16.3.17;Initial Catalog=testadms;User Id=sa;Password=admin#cgc;")
                s1 = "select isnull(flagah,0),isnull(flagf,0),isnull(flagr,0) from mststudents where uin ='" & txtauin.Text.Trim() & "' and sname is not null"
                If (con.State = ConnectionState.Closed) Then
                    con.Open()
                End If
                da1 = New SqlDataAdapter(s1, con)
                dt1 = New DataTable
                da1.Fill(dt1)
                If (dt1.Rows.Count = 0) Then
                    MessageBox.Show("No Record Found")
                    txtauin.Text = ""
                Else
                    If (Convert.ToInt32(dt1.Rows(0)(0).ToString()) = 1) Then
                        btnah.BackColor = Color.Green
                        btnah.Visible = True

                    Else
                        btnah.BackColor = Color.Red
                        btnah.Visible = True

                    End If
                    If (Convert.ToInt32(dt1.Rows(0)(1).ToString()) = 1) Then
                        btnf.BackColor = Color.Green
                        btnf.Visible = True
                    Else
                        btnf.BackColor = Color.Red
                        btnf.Visible = True
                    End If
                    If (Convert.ToInt32(dt1.Rows(0)(2).ToString()) = 1) Then
                        btnr.BackColor = Color.Green
                        btnr.Visible = True
                    Else
                        btnr.BackColor = Color.Red
                        btnr.Visible = True
                    End If
                End If
            End If
        Catch ex As Exception
            MsgBox("Error Occurred " + ex.ToString())
        Finally
            If ConnectionState.Open Then
                con.Close()
            End If
        End Try
ASKER CERTIFIED SOLUTION
Dirk Haest
Project manager

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