DataGridViewの行全体にグラデーションをかける方法

DataGridViewの行全体にグラデーションをかける方法
VB.NET

Private Sub dgv1_RowPrePaint(ByVal sender As Object, _
        ByVal e As DataGridViewRowPrePaintEventArgs) _
        Handles dgv1.RowPrePaint
    If (e.PaintParts And DataGridViewPaintParts.Background) = _
            DataGridViewPaintParts.Background Then
        Dim bColor1, bColor2 As Color
        If (e.PaintParts And DataGridViewPaintParts.SelectionBackground) = _
                DataGridViewPaintParts.SelectionBackground AndAlso _
            (e.State And DataGridViewElementStates.Selected) = _
                DataGridViewElementStates.Selected Then
            bColor1 = e.InheritedRowStyle.SelectionBackColor
            bColor2 = Color.Black
        Else
            bColor1 = e.InheritedRowStyle.BackColor
            bColor2 = Color.YellowGreen
        End If

        Dim dgv As DataGridView = CType(sender, DataGridView)
        Dim rectLeft2 As Integer = _
            IIf(dgv.RowHeadersVisible, dgv.RowHeadersWidth, 0)
        Dim rectLeft As Integer = _
            rectLeft2 - dgv.HorizontalScrollingOffset
        Dim rectWidth As Integer = _
            dgv.Columns.GetColumnsWidth(DataGridViewElementStates.Visible)
        Dim rect As New Rectangle(rectLeft, e.RowBounds.Top, _
            rectWidth, e.RowBounds.Height - 1)

        Using b As New System.Drawing.Drawing2D.LinearGradientBrush( _
            rect, bColor1, bColor2, _
            System.Drawing.Drawing2D.LinearGradientMode.Horizontal)

            rect.X = rectLeft2
            rect.Width -= dgv.HorizontalScrollingOffset
            e.Graphics.FillRectangle(b, rect)
        End Using
        e.PaintHeader(True)
        e.PaintParts = _
            e.PaintParts And Not DataGridViewPaintParts.Background
    End If
End Sub

Private Sub dgv1_ColumnWidthChanged(ByVal sender As Object, _
        ByVal e As DataGridViewColumnEventArgs) _
        Handles dgv1.ColumnWidthChanged
    Dim dgv As DataGridView = CType(sender, DataGridView)
    dgv.Invalidate()
End Sub

C#

private void dgv1_RowPrePaint(object sender,
    DataGridViewRowPrePaintEventArgs e)
{
    if ((e.PaintParts & DataGridViewPaintParts.Background) ==
        DataGridViewPaintParts.Background)
    {
        Color bColor1, bColor2;
        if ((e.PaintParts & DataGridViewPaintParts.SelectionBackground) ==
                DataGridViewPaintParts.SelectionBackground &&
            (e.State & DataGridViewElementStates.Selected) ==
                DataGridViewElementStates.Selected)
        {
            bColor1 = e.InheritedRowStyle.SelectionBackColor;
            bColor2 = Color.Black;
        }
        else
        {
            bColor1 = e.InheritedRowStyle.BackColor;
            bColor2 = Color.YellowGreen;
        }

        DataGridView dgv = (DataGridView)sender;
        int rectLeft2 = dgv.RowHeadersVisible ? dgv.RowHeadersWidth : 0;
        int rectLeft = rectLeft2 - dgv.HorizontalScrollingOffset;
        int rectWidth = dgv.Columns.GetColumnsWidth(
            DataGridViewElementStates.Visible);
        Rectangle rect = new Rectangle(rectLeft, e.RowBounds.Top,
            rectWidth, e.RowBounds.Height - 1);

        using (System.Drawing.Drawing2D.LinearGradientBrush b =
            new System.Drawing.Drawing2D.LinearGradientBrush(
            rect, bColor1, bColor2,
            System.Drawing.Drawing2D.LinearGradientMode.Horizontal))
        {
            rect.X = rectLeft2;
            rect.Width -= dgv.HorizontalScrollingOffset;
            e.Graphics.FillRectangle(b, rect);
        }

        e.PaintHeader(true);

        e.PaintParts &= ~DataGridViewPaintParts.Background;
    }
}

private void dgv1_ColumnWidthChanged(object sender,
    DataGridViewColumnEventArgs e)
{
    DataGridView dgv = (DataGridView)sender;
    dgv.Invalidate();
}