[RESOLVED] Buffer cannot be null

[chdboy]

I'm trying to get values from DataGridView to the another form in textboxes and in Picturebox ,data in textboxes are there but when I trying to get a picture in a picturebox from DB it gives me this error



and here is the code

 Private Sub dgv1_CellDoubleClick(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles DGV1.CellDoubleClick
        Dim frm As New Edit_Employee()
        frm.MdiParent = Mainfrm
        frm.Show()
        
        frm.TextBox1.Text = DGV1.Rows(e.RowIndex).Cells(1).Value.ToString
        frm.TextBox2.Text = DGV1.CurrentRow.Cells(2).Value.ToString
        frm.TextBox3.Text = DGV1.CurrentRow.Cells(3).Value.ToString
        frm.TextBox4.Text = DGV1.CurrentRow.Cells(4).Value.ToString
        frm.TextBox5.Text = DGV1.CurrentRow.Cells(5).Value.ToString
        frm.TextBox6.Text = DGV1.CurrentRow.Cells(6).Value.ToString
        frm.TextBox7.Text = DGV1.CurrentRow.Cells(7).Value.ToString
        frm.TextBox8.Text = DGV1.CurrentRow.Cells(8).Value.ToString
        frm.DateTimePicker1.Text = DGV1.CurrentRow.Cells(9).Value.ToString
        frm.TextBox9.Text = DGV1.CurrentRow.Cells(10).Value.ToString
        frm.TextBox10.Text = DGV1.CurrentRow.Cells(11).Value.ToString
        frm.TextBox11.Text = DGV1.CurrentRow.Cells(12).Value.ToString
        frm.TextBox12.Text = DGV1.CurrentRow.Cells(13).Value.ToString
        frm.TextBox13.Text = DGV1.CurrentRow.Cells(14).Value.ToString
        frm.TextBox14.Text = DGV1.CurrentRow.Cells(15).Value.ToString
        frm.TextBox15.Text = DGV1.CurrentRow.Cells(16).Value.ToString
        frm.DateTimePicker2.Text = DGV1.CurrentRow.Cells(17).Value.ToString
        frm.DateTimePicker3.Text = DGV1.CurrentRow.Cells(18).Value.ToString
        frm.TextBox16.Text = DGV1.CurrentRow.Cells(19).Value.ToString
        frm.TextBox17.Text = DGV1.CurrentRow.Cells(20).Value.ToString
        frm.TextBox18.Text = DGV1.CurrentRow.Cells(21).Value.ToString
        frm.TextBox19.Text = DGV1.CurrentRow.Cells(22).Value.ToString
        frm.Txtbonus.Text = DGV1.CurrentRow.Cells(23).Value.ToString
        frm.TextBox21.Text = DGV1.CurrentRow.Cells(24).Value.ToString
        

        Try
            Dim connection As New SqlConnection("Data Source=.\SQLEXPRESS;AttachDbFilename=C:\Users\Danial\documents\visual studio 2010\Projects\ESI_PF_Payroll_V1\ESI_PF_Payroll_V1\Pay.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True")
            Dim command As New SqlCommand("SELECT Imagedata FROM Employee WHERE Firstname = '" & TextBox1.Text & "'", connection)

            connection.Open()

            Dim pictureData As Byte() = DirectCast(command.ExecuteScalar(), Byte())

            connection.Close()

            Dim picture As Image = Nothing

            'Create a stream in memory containing the bytes that comprise the image.
            Using stream As New IO.MemoryStream(pictureData)
                'Read the stream and create an Image object from the data.
                picture = Image.FromStream(stream)
                
                frm.PB1.Image = (picture)
            End Using
        Catch ex As Exception
            MsgBox(ex.Message)
        End Try

        
        frm.Txtfilepath1.Text = DGV1.CurrentRow.Cells(27).Value.ToString
        frm.Txtfilename.Text = DGV1.CurrentRow.Cells(26).Value.ToString
        frm.TxtGross.Text = DGV1.CurrentRow.Cells(28).Value.ToString
        frm.RTB1.Text = DGV1.CurrentRow.Cells(29).Value.ToString
    End Sub

[Joacim Andersson]

It would be nice if you temporarily removed your Try Catch code so that you could tell us which line you're getting the error. But I suspect that you get it on your Using stream line and that your pictureData is null.

[dunfiddlin]

Clearly pictureData is null causing the failure of the Stream.

[chdboy]

It would be nice if you temporarily removed your Try Catch code so that you could tell us which line you're getting the error. But I suspect that you get it on your Using stream line and that your pictureData is null.

Yes you are right I'm getting an error on that line.
here is the screen shot without Try and catch


How can I change the code to make it work?

[Joacim Andersson]

Yes, so obviously your query does not return a byte array.

[chdboy]

ok my sql query has a problem ?

[Joacim Andersson]

Yes, obviously this call returns null.

 Dim pictureData As Byte() = DirectCast(command.ExecuteScalar(), Byte())

Try setting a break point at this line as see what you get.

[chdboy]

I have changed the Sql statement ..where clause is gone,I have got the image but not according to the name,just one picture is showing no matter which row I click .

Dim connection As New SqlConnection("Data Source=.\SQLEXPRESS;AttachDbFilename=C:\Users\Danial\documents\visual studio 2010\Projects\ESI_PF_Payroll_V1\ESI_PF_Payroll_V1\Pay.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True")
        connection.Open()
        Dim command As New SqlCommand("SELECT Imagedata FROM Employee ", connection)
Dim pictureData As Byte() = DirectCast(command.ExecuteScalar(), Byte())
        connection.Close()
        Dim picture As Image = Nothing

        'Create a stream in memory containing the bytes that comprise the image.
        Using stream As New IO.MemoryStream(pictureData)
            'Read the stream and create an Image object from the data.
            picture = Image.FromStream(stream)
            frm.PB1.Image = (picture)
        End Using

[Joacim Andersson]

Yes, you're calling ExecuteScalar which will only return 1 result. Call ExecuteReader instead and loop through the result.

[chdboy]

My where clause has the problem ...so I changed it to this

where Firstname = '" & _
                  DGV1.CurrentRow.Cells(1).Value() & "'"

and now it works fine
Thank you all for guiding me and helping me in this thread ,I have learned some new things in this process .I hope I will keep that in mind.

[chdboy]

Now how do I make this thread [solved]?

[Joacim Andersson]

Pull down the Thread Tools menu close to the top and select Mark as resolved.