/// <summary>
/// 創建Drill-Down樣式的Title
/// </summary>
/// <param name="chart">ChartControl</param>
/// <param name="title">title文字</param>
/// <param name="visible">是否可見</param>
public static void AddDrillDownTitle(this ChartControl chart, string title, bool visible)
{
    ChartTitle _chartTitle = new ChartTitle();
    _chartTitle.Alignment = StringAlignment.Near;
    _chartTitle.Antialiasing = false;
    _chartTitle.Font = new Font("Tahoma", 10F, FontStyle.Underline);
    _chartTitle.Indent = 20;
    _chartTitle.Text = title;
    _chartTitle.TextColor = Color.RoyalBlue;
    _chartTitle.Visible = false;
    chart.Titles.Add(_chartTitle);
}