گرفتن مقدار یه سطر انتخابی از گریدویو

[gheysar14]

سلام
من یه گریدویو برای آرشیو خبرنامه دارم که در هر سطر اون یه باتون برای ارسال خبرنامه گذاشتم . که با کیلیک باتون خبرنامه مربوط به همون سطر ارسال بشه
ولی موقع send کردن ارور Object reference not set to an instance of an object. میده
دقیقاً تو خط mail.Subject = GridView2.SelectedRow.Cells(1).Text ارور میده





Protected Sub btn_send_Click(ByVal sender As Object, ByVal e As System.EventArgs)
Dim i As Integer
Dim email As String
Dim listMail As New ArrayList()
Dim dr As SqlDataReader
Dim smtp As New System.Net.Mail.SmtpClient("mail.yahoo.com")
objCommand.Connection = objConnection
objCommand.CommandType = CommandType.Text
objCommand.CommandText = "SELECT [email] FROM [tblUser]"
objConnection.Open()
dr = objCommand.ExecuteReader
While (dr.Read)
i = i + 1 - 1
email = dr.Item(i).ToString
listMail.Add(email)
End While
dr.Close()
Try
For Each email In listMail
Dim mail As New System.Net.Mail.MailMessage()
mail.IsBodyHtml = True
mail.BodyEncoding = Encoding.GetEncoding("UTF-8")
mail.From = New System.Net.Mail.MailAddress("me@yahoo.com")
mail.Subject = GridView2.SelectedRow.Cells(1).Text
mail.To.Add(email)
mail.Body = GridView2.SelectedRow.Cells(2).Text
smtp.Host = "mail.yahoo.com"
smtp.Send(mail)
Next
objConnection.Close()
Label1.Text = "Message Sent Successfully"
Catch ex As Exception
Label1.Text = ex.Message.ToString
objConnection.Close()
End Try
End Sub