After some effort, I finally write down the code with some sentences. Its general code, which can be called using any Grid Paint method for C # WinForm, give it the names Grid, The Columns and the Graphics Paint object
I added a fill rectangle of size 4, which starts from the previous column on the right-2 to the next column on the left + 2, so it hides the vertical panel
Public Sub VerticalBarHide(ByVal grd As KryptonExtendedGrid, ByVal colname As String(), ByVal e As System.Drawing.Graphics)
Dim rectHeader As Rectangle
grd.EnableHeadersVisualStyles = False
Dim bgColor As Color
bgColor = grd.ColumnHeadersDefaultCellStyle.BackColor
For Each name As String In colname
rectHeader = grd.GetCellDisplayRectangle(grd.Columns(name).Index, -1, True)
rectHeader.X = rectHeader.X + rectHeader.Width - 2
rectHeader.Y += 1
rectHeader.Width = 2 * 2
rectHeader.Height -= 2
e.FillRectangle(New SolidBrush(bgColor), rectHeader)
Next
End Sub