/// <summary>
        /// 目标值系列曲线
         /// </summary>
        private Series DestSeries { get { return chartMain.Series.Count > 0 ? chartMain.Series[0] : null; } }

        /// <summary>
        /// X轴值范围
        /// </summary>
        private AxisRange XRange
        {
            get
            {
                SwiftPlotDiagram diagram = chartMain.Diagram as SwiftPlotDiagram;
                if (diagram != null)
                    return diagram.AxisX.Range;
                return null;
            }
        }

       private void SetChartData(CollectPointData pointData)
        {
            if (this.InvokeRequired)
            {
                this.Invoke(new Action<CollectPointData>(SetChartData), pointData);
            }
            else
            {
                decimal colValue = pointData.Value;

                RealSeries.Points.Add(new SeriesPoint(pointData.Time, colValue));
                float minTime = pointData.Time - 30f;
                for (int i = 0; i < DestSeries.Points.Count; i++)
                {
                    if (DestSeries.Points[i].NumericalArgument > minTime)
                    {
                       DestSeries.Points.RemoveRange(0, i);
                       break;
                    }
                }

                XRange.SetMinMaxValues(minTime, pointData.Time);
            }
        }

       public class CollectPointData
       {
        public CollectPointData() { }

        public CollectPointData(float time, decimal value)
            : this()
        {
            this.Time = time;
            this.Value = value;
        }

        public float Time { get; set; }
        public decimal Value { get; set; }
    }