/// <summary>
/// 設置餅狀圖的Lable位置
/// </summary>
/// <param name="series">Series</param>
/// <param name="lablePosition">PieSeriesLabelPosition枚舉</param>
public static void SetLablePosition(this Series series, PieSeriesLabelPosition lablePosition)
{
    if (series.Label is PieSeriesLabel)
    {
 PieSeriesLabel _label = series.Label as PieSeriesLabel;
 _label.Position = lablePosition;
    }
    //if (series.Label is Pie3DSeriesLabel)
    //{
    //    Pie3DSeriesLabel _label = series.Label as Pie3DSeriesLabel;
    //    _label.Position = lablePosition;
    //}

}