如何使一个界面上两个zedGraph收到数据 都实时的刷新 不卡死

[有时想起]

示例代码如下所示： 现在屏蔽掉一个zedgraph刷新的话 刷新可用 不然的话 就会卡死界面

 private void Form1_Load(object sender, EventArgs e)
        {
            initZedGraph(zedGraphControl1);
            Task task = new Task(new Action(sampling));
            task.Start();
        }
        private PointPairList list1 = new PointPairList();  //AD1的点
        private PointPairList list2 = new PointPairList();  //AD2的点
        private PointPairList list3 = new PointPairList();
        private PointPairList list4 = new PointPairList();  //AD1的点
        private PointPairList list5 = new PointPairList();  //AD2的点
        private PointPairList list6 = new PointPairList();
        private void initZedGraph(ZedGraphControl zedgraph)
        {
            GraphPane myPane = zedgraph.GraphPane;
            if (zedgraph == zedGraphControl1)
            {
                myPane.Title.Text = "1";
                LineItem Curve1 = myPane.AddCurve("电压1", list1, Color.Yellow, SymbolType.None);
                LineItem Curve2 = myPane.AddCurve("电压2", list2, Color.Green, SymbolType.None);
                LineItem Curve3 = myPane.AddCurve("电压3", list3, Color.Red, SymbolType.None);

                Curve1.IsY2Axis = true;
                Curve2.IsY2Axis = true;
            }
            if (zedgraph == zedGraphControl2)
            {
                myPane.Title.Text = "2";
                LineItem Curve1 = myPane.AddCurve("电压1", list4, Color.Yellow, SymbolType.None);
                LineItem Curve2 = myPane.AddCurve("电压2", list5, Color.Green, SymbolType.None);
                LineItem Curve3 = myPane.AddCurve("电压3", list6, Color.Red, SymbolType.None);

                Curve1.IsY2Axis = true;
                Curve2.IsY2Axis = true;
            }
            myPane.XAxis.Title.Text = "时间";
            myPane.YAxis.Title.Text = "距离(μm)";//"电压值"; //
            myPane.XAxis.Scale.Max = 100;
            myPane.XAxis.Scale.Min = 0;
            myPane.XAxis.MajorTic.IsOpposite = false;
            myPane.XAxis.MinorTic.IsOpposite = false;
            myPane.YAxis.Scale.Max = 3500;
            myPane.YAxis.Scale.Min = -3500;
            myPane.YAxis.MajorTic.IsOpposite = false;
            myPane.YAxis.MinorTic.IsOpposite = false; //小刻度
            myPane.YAxis.Scale.Align = AlignP.Inside;

            myPane.Y2Axis.Title.Text = "电压值";
            myPane.Y2Axis.Scale.Max = 4;
            myPane.Y2Axis.Scale.Min = -4;
            myPane.Y2Axis.Scale.FontSpec.FontColor = Color.Black;
            myPane.Y2Axis.Title.FontSpec.FontColor = Color.Black;
            myPane.Y2Axis.MajorTic.IsOpposite = false;
            myPane.Y2Axis.MinorTic.IsOpposite = false;
            myPane.Y2Axis.Scale.Align = AlignP.Inside;
            myPane.Y2Axis.IsVisible = true;
            myPane.Chart.Fill = new Fill(Color.White, Color.SteelBlue, 45.0F);
            myPane.Legend.IsVisible = false;

            zedgraph.AxisChange();
            zedgraph.Refresh();
        }
        int count = 0;
        private void sampling()
        {
            int itime = 0;
            while (true)
            {

               
                    Random rd = new Random();　　//无参即为使用系统时钟为种子
                
                list1.Add((double)itime, rd.Next(1,4));
                list2.Add((double)itime, rd.Next(1, 4));
                list4.Add((double)itime, rd.Next(1, 4));
                list5.Add((double)itime, rd.Next(1, 4));
                list3.Add((double)itime, rd.Next(1, 4000));
                list6.Add((double)itime, rd.Next(1, 4000));


                count++;
                if (count == 200)
                {
                    count = 0;
                    itime++;
                    if (itime > 10000)
                    {
                        itime = 0;
                        list1.Clear();
                        list2.Clear();
                        list4.Clear();
                        list5.Clear();
                        list3.Clear();
                        list6.Clear();
                    }
                    //Thread.Sleep(100);
                    if (itime >= 100)
                    {
                        zedGraphControl1.GraphPane.XAxis.Scale.Min = (double)itime - 100;
                        zedGraphControl1.GraphPane.XAxis.Scale.Max = (double)itime;
                        RefreshGraph(zedGraphControl1);
                        zedGraphControl2.GraphPane.XAxis.Scale.Min = (double)itime - 100;
                        zedGraphControl2.GraphPane.XAxis.Scale.Max = (double)itime;
                        RefreshGraph(zedGraphControl2);
                    }
                }
            }
        }
        private delegate void RefreshDelegate();
        private void RefreshGraph(ZedGraphControl zg)
        {
            if (zg == null)
                return;
            //判断是否是非创建控件的线程调用控件
            if (zg.InvokeRequired)
            {
                RefreshDelegate a = new RefreshDelegate(new Action(() => { zg.Invalidate();  }));
                zg.BeginInvoke(a);
            }
            else
            {
                zg.AxisChange();
                zg.Invalidate();
                zg.Refresh();
            }
        }

[有时想起]

求解。。。。。。。。