private void ChartRevenueDetail_MouseMove(object sender, MouseEventArgs e) { if (e.Y <= -1) { an.Visible = false; return; } else { an.Visible = true; t.SetToolTip(chartRevenueRouteDetail, an.AnchorY.ToString("C0")); } an.BeginPlacement(); an.AnchorY = chartRevenueRouteDetail.ChartAreas[0].AxisY.PixelPositionToValue(e.Y); an.EndPlacement(); }