Merge Cells in DataGridView - How to do it correctly?

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VB

DataGridView

Hi!

I'm merging all cells of a row in a DataGridView. However, when i click on or select a merged cell, the display is flawed:

Public Class Form1

  Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
    With DataGridView1
      .Columns.Add("Col1", "Col1")
      .Columns.Add("Col2", "Col2")
      .Columns.Add("Col3", "Col3")
      .Columns.Add("Col4", "Col4")
      .Rows.Add("", "", "", "TitleTitleTitleTitleTitleTitle")
      .Rows.Add("Col1", "Col2", "Col3", "Col4")
      .Rows.Add("Col1", "Col2", "Col3", "Col4")
      .Rows.Add("Col1", "Col2", "Col3", "Col4")
      .Rows.Add("", "", "", "TitleTitleTitleTitleTitleTitle")
      .Rows.Add("Col1", "Col2", "Col3", "Col4")
      .Rows.Add("Col1", "Col2", "Col3", "Col4")
      .RowHeadersVisible = False
      .ReadOnly = True
      .SelectionMode = DataGridViewSelectionMode.FullRowSelect
      .AllowUserToResizeRows = False
    End With
  End Sub

  Private Sub DataGridView1_RowPrePaint(sender As Object, e As System.Windows.Forms.DataGridViewRowPrePaintEventArgs) Handles DataGridView1.RowPrePaint
    If e.RowIndex = 0 OrElse e.RowIndex = 4 Then
      DataGridView1.Rows(e.RowIndex).DefaultCellStyle.BackColor = Color.CadetBlue
    End If
  End Sub

  Private Sub DataGridView1_CellPainting(sender As Object, e As System.Windows.Forms.DataGridViewCellPaintingEventArgs) Handles DataGridView1.CellPainting
    If e.RowIndex = 0 OrElse e.RowIndex = 4 Then
      Dim gridBrush As Brush = New SolidBrush(DataGridView1.GridColor)
      Dim backColorBrush As Brush = New SolidBrush(e.CellStyle.BackColor)
      Dim gridLinePen As Pen = New Pen(gridBrush)

      e.Graphics.FillRectangle(backColorBrush, e.CellBounds)
      If e.ColumnIndex = 3 Then
        e.Graphics.DrawString(CType(e.Value, String),
                              e.CellStyle.Font, Brushes.Black,
                              4, Convert.ToSingle(e.CellBounds.Y + 4))
      End If
      e.Handled = True
    End If
  End Sub

End Class

If I add "Invalidate" as follows it seems to work. However, is there a better way to make it work?

Private Sub DataGridView1_MouseDown(sender As Object, e As System.Windows.Forms.MouseEventArgs) Handles DataGridView1.MouseDown
  DataGridView1.Invalidate()
End Sub
Private Sub DataGridView1_CellClick(sender As Object, e As System.Windows.Forms.DataGridViewCellEventArgs) Handles DataGridView1.CellClick
  DataGridView1.Invalidate()
End Sub
Private Sub DataGridView1_SelectionChanged(sender As Object, e As System.EventArgs) Handles DataGridView1.SelectionChanged
  DataGridView1.Invalidate()
End Sub
Private Sub DataGridView1_KeyDown(sender As Object, e As System.Windows.Forms.KeyEventArgs) Handles DataGridView1.KeyDown
  DataGridView1.Invalidate()
End Sub
Private Sub DataGridView1_CellDoubleClick(sender As Object, e As System.Windows.Forms.DataGridViewCellEventArgs) Handles DataGridView1.CellDoubleClick
  DataGridView1.Invalidate()
End Sub