用鼠标放大图表中的每一点

我的c#windows应用程序上有一个图表。当鼠标放在图表上时，我想缩放图表的每个点。像谷歌地图

我的意思是我不想缩放图表的所有部分我想要缩放只是特定的点像谷歌地图

代码：

public partial class Form1 : Form
    {
        int[] myArrayX = new int[5];
        double[] myArrayY = new double[5];
        int lastX = -1;
        double lastY = -0.6;
        double xmax;
        Graph.Chart chart;
        public Form1()
        {
            InitializeComponent();
            this.MouseWheel += new MouseEventHandler(Form1_MouseWheel);
        }
        void Form1_MouseWheel(object sender, MouseEventArgs e)
        {
            try
            {
                if (e.Delta > 0)
                {
                    double xMin = chart.ChartAreas["draw"].AxisX.ScaleView.ViewMinimum;
                    double xMax = chart.ChartAreas["draw"].AxisX.ScaleView.ViewMaximum;
                    double yMin = chart.ChartAreas["draw"].AxisY.ScaleView.ViewMinimum;
                    double yMax = chart.ChartAreas["draw"].AxisY.ScaleView.ViewMaximum;
                    double posXStart = chart.ChartAreas["draw"].AxisX.PixelPositionToValue(e.Location.X) - (xMax - xMin) / 2;
                    double posXFinish = chart.ChartAreas["draw"].AxisX.PixelPositionToValue(e.Location.X) + (xMax - xMin) / 2;
                    double posYStart = chart.ChartAreas["draw"].AxisY.PixelPositionToValue(e.Location.Y) - (yMax - yMin) / 2;
                    double posYFinish = chart.ChartAreas["draw"].AxisY.PixelPositionToValue(e.Location.Y) + (yMax - yMin) / 2;
                    chart.ChartAreas["draw"].AxisX.ScaleView.Zoom(posXStart, posXFinish);
                    chart.ChartAreas["draw"].AxisY.ScaleView.Zoom(posYStart, posYFinish);
                }
                else if (e.Delta < 0)
                {
                    ZoomOut();
                }
            }
            catch { }

        }
        private void ZoomOut()
        {
            chart.ChartAreas["draw"].AxisX.ScaleView.ZoomReset();
            chart.ChartAreas["draw"].AxisY.ScaleView.ZoomReset();
        }

        void CreateNewGraph()
        {
            // Create new Graph
            chart = new Graph.Chart();

            chart.Location = new System.Drawing.Point(13, 185);

            chart.Size = new System.Drawing.Size(900, 500);

            chart.ChartAreas.Add("draw");


            chart.ChartAreas["draw"].AxisX.Minimum = 0;
            chart.ChartAreas["draw"].AxisX.Maximum = 20;

            chart.ChartAreas["draw"].AxisX.Interval = 1;

            chart.ChartAreas["draw"].AxisX.MajorGrid.LineColor = Color.White;

            chart.ChartAreas["draw"].AxisX.MajorGrid.LineDashStyle = Graph.ChartDashStyle.Dash;

            chart.ChartAreas["draw"].AxisY.Minimum = -0.4;
            chart.ChartAreas["draw"].AxisY.Maximum = 1;

            chart.ChartAreas["draw"].AxisY.Interval = 0.2;

            chart.ChartAreas["draw"].AxisY.MajorGrid.LineColor = Color.White;

            chart.ChartAreas["draw"].AxisY.MajorGrid.LineDashStyle = Graph.ChartDashStyle.Dash;

            chart.ChartAreas["draw"].BackColor = Color.Black;

            var series = chart.Series.Add("Test");

            chart.Series["Test"].ChartType = Graph.SeriesChartType.Line;

            chart.Series["Test"].Color = Color.Yellow;

            chart.Series["Test"].BorderWidth = 3;

            chart.Legends.Add("MyLegend");
            chart.Legends["MyLegend"].BorderColor = Color.YellowGreen;
            // Set automatic zooming
            chart.ChartAreas["draw"].AxisX.ScaleView.Zoomable = true;
            chart.ChartAreas["draw"].AxisY.ScaleView.Zoomable = true;
            // Set automatic scrolling 
            chart.ChartAreas["draw"].CursorX.AutoScroll = true;
            chart.ChartAreas["draw"].CursorY.AutoScroll = true;
            // Allow user selection for Zoom
            chart.ChartAreas["draw"].CursorX.IsUserSelectionEnabled = true;
            chart.ChartAreas["draw"].CursorY.IsUserSelectionEnabled = true;
            chart.ChartAreas["draw"].AxisX.ScaleView.Zoomable = true;
            chart.ChartAreas["draw"].AxisY.ScaleView.Zoomable = true;
            //chart.MouseWheel += new MouseEventHandler(chart_MouseWheel);
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            CreateNewGraph();
        }
        private void timer1_Tick(object sender, EventArgs e)
        {
            fillarray();
            for (int i = 1; i <= 5; i += 1)
            {
                chart.Series["Test"].Points.AddXY(myArrayX[i - 1], myArrayY[i - 1]);
                xmax = myArrayX[i - 1];
            }
            if (xmax >= 20)
            {
                chart.ChartAreas["draw"].AxisX.ScrollBar.Enabled = true;
                chart.ChartAreas["draw"].AxisX.ScaleView.Zoomable = true;
                chart.ChartAreas["draw"].AxisX.ScaleView.Zoom(0, xmax);
            }
            Controls.Add(this.chart);
        }
        public void fillarray()
        {
            for (int i = 1; i <= 5; i += 1)
            {
                lastX = lastX + 1;
                myArrayX[i - 1] = lastX;
            }
            for (int i = 1; i < 5; i += 1)
            {
                lastY = lastY + 0.2;
                myArrayY[i - 1] = lastY;
            }

        }
    }