[RESOLVED] DataGridView visible interference while scrolling

[projecttoday]

I have a datagridview on a form which displays data. The datagridview scrolls both horizontally and vertically. It works but when I scroll to the right and then scroll up and down you can see flashes of gray on the view during the scroll. Once you stop scrolling the gray disappears. This affects approximately the right third of the dgv. If I don't scroll to the right and scroll up and down I don't see these artifacts. What can I do to get rid of these flashes of gray while vertical scrolling?

[kareninstructor]

Hello,

Are there any events you have the DataGridView subscribed to e.g. CellFormatting etc.

[projecttoday]

There is a cellclick event.

[projecttoday]

Removing the cellclick handler made no difference.

The part of the dgv where the artifacts appear is on the right side and corresponds, almost, to the part which cannot be seen when the dgv is scrolled fully left.

[.paul.]

Try subclassing your DGV and making it DoubleBuffered:

Public Class DoubleBufferedDataGridView
    Inherits DataGridView

    Public Sub New()
        Me.DoubleBuffered = True
    End Sub

End Class

[projecttoday]

Thanks. I've never heard of a double-buffered datagridview. My dgv is created with code. Simply adding "DoubleBuffered" to the declaration did not work. What to do?

Dim ReportDataGridView as DataGridView

ReportDataGridView = New DataGridView
ReportDataGridView.Name = "Stock Items Report"
ReportDataGridView.Left = 14
ReportDataGridView.Top = 82
ReportDataGridView.Height = 520
ReportDataGridView.Width = 956
ReportDataGridView.BorderStyle = BorderStyle.None
ReportDataGridView.RowsDefaultCellStyle.SelectionBackColor = Color.DarkKhaki
ReportDataGridView.RowsDefaultCellStyle.SelectionForeColor = Color.Black
ReportDataGridView.RowsDefaultCellStyle.BackColor = Color.LightYellow
ReportDataGridView.RowsDefaultCellStyle.Font = New Font("Microsoft Sans Serif", 12)
ReportDataGridView.AlternatingRowsDefaultCellStyle.BackColor = Color.PaleGoldenrod
ReportDataGridView.ColumnHeadersDefaultCellStyle.Font = New Font("Microsoft Sans Serif", 11)
ReportDataGridView.ColumnHeadersHeight = 28
ReportDataGridView.AllowUserToAddRows = False
ReportDataGridView.AllowUserToDeleteRows = False
AddHandler ReportDataGridView.CellClick, AddressOf ReportDataGridView_CellClick

Controls.Add(ReportDataGridView)

[.paul.]

Add the DoubleBufferedDataGridView class to your project (from post #5), then:

Dim ReportDataGridView as DoubleBufferedDataGridView

ReportDataGridView = New DoubleBufferedDataGridView

It will automatically be doublebuffered with no further code, and the dgv will be as a standard dgv except double buffering, which will hopefully improve the graphics performance...

[projecttoday]

When I change Dim ReportDataGridView as DataGridView to Dim ReportDataGridView as DoubleBufferedDataGridView I get the message "Type DoubleBufferedDataGridView is not defined". I'm using Visual Basic 2010 Express.

[.paul.]

Did you add a class, name it DoubleBufferedDataGridView and paste the code from post #5 into the class as i told you to do?
DoubleBufferedDataGridView is a custom control. It is necessary because that is the only way to apply double buffering to a dgv.

[projecttoday]

It's working beautiflly! Thank you. You rate a 10.

[.paul.]

Glad i was able to help. That was my best shot. If that hadn't worked it might've been unsolveable.