Object reference not set to an instance of an object in vb.net

Question

I am getting the error:

Object reference not set to an instance of an object.

This appears when I'm trying to upload any file to my database. This is a project I am developing to deliver for my school (the final exam)

Here's my code:

 Try
        OpenFileDialog.Filter = "All files (*.*)|*.*| JPEG FILES(*.jpg)|*.jpg| RAW FILES (*.raw)|*.raw| WORD FILES (*.doc)|*.doc| WORD FILES (*.docx)|*.docx| EXCEL FILES (*.xls)|*.xls| EXCEL Files (*.xlsx)|*.xlsx| PNG Files (*.png)|*.png| GIF FILES (*.gif)|*.gif| PDF FILES (*.pdf)|*.pdf| RAR Files (*.rar)|*.rar| AUTOCAD FILES (*.dwg)|*.dwg| EXE FILES (*.exe)|*.exe| ZIP FILES (*.zip)|*.zip| TXT FILES (*.txt)|*.txt"
        OpenFileDialog.FilterIndex = 1
        OpenFileDialog.Title = "Open File"
        OpenFileDialog.Multiselect = True

        obj_openfile = OpenFileDialog

        'Show The Dialog
        If obj_openfile.ShowDialog = Windows.Forms.DialogResult.OK Then
            in_file = obj_openfile.FileName.ToString
            Dim fich As String = obj_openfile.SafeFileName
            obj_openfile.Dispose()
            obj_openfile = Nothing
            con.Close()
            con.ConnectionString = "Data Source=IZZ;Initial Catalog=regteste;Integrated Security=True"
            con.Open()

            'Converter to bytesream
            Dim fs As FileStream
            fs = New FileStream(in_file, FileMode.Open, FileAccess.Read)
            Dim docByte As Byte() = New Byte(fs.Length - 1) {}
            fs.Read(docByte, 0, System.Convert.ToInt32(fs.Length))
            fs.Close()

            Dim filebyte As Byte() = Nothing
            filebyte = System.IO.File.ReadAllBytes(obj_openfile.FileName)
            cmd = New SqlCommand("INSERT INTO Filestelefones_pt (Name,Data) VALUES (@Name, @Data)", con)
            cmd.Parameters.AddWithValue("@Name", fich)
            cmd.Parameters.AddWithValue("@Data", docByte)
            cmd.ExecuteNonQuery()
            con.Close()
            con.Open()

            txtabrir.Text = in_file

        End If
    Catch ex As Exception
        MsgBox(ex.Message)
    End Try
End Sub

Do you know where it fails? Can you provide more details to the error? — David Brossard, May 23 '14 at 15:36
possible duplicate of [What is a NullReferenceException and how do I fix it?](http://stackoverflow.com/questions/4660142/what-is-a-nullreferenceexception-and-how-do-i-fix-it) to start, get rid of the try/catch to identify exactly where the error is — Ňɏssa Pøngjǣrdenlarp, May 23 '14 at 15:54
Yes plutonix is the same but i'm newbie in this type of comunity. Thank you ;) — user3669457, May 23 '14 at 21:15

score 0 · Accepted Answer · answered May 23 '14 at 16:29

The easiest way to find these problems is to put a breakpoint in your code, hit F5 and step through the lines in the debugger. It's also quicker than waiting an answer.

The most likely culprit in you're code is obj_openfile.

If you look at your code in the If, you'll notice the following lines of code:

obj_openfile.Dispose()
obj_openfile = Nothing

Then a little farther down, you have this:

Dim filebyte As Byte() = Nothing
filebyte = System.IO.File.ReadAllBytes(obj_openfile.FileName)

At this point in the program, you've already set obj_openfile to Nothing (null), so this is most likely where you're getting the error, as you're trying to read the property of a null object.

Thank you so much for all your help. It was spot on. :) – user3669457 May 23 '14 at 21:12 — user3669457, May 23 '14 at 21:12

Object reference not set to an instance of an object in vb.net

1 Answers1