Winform Chart 通过X值取得曲线的Y值

Question

一个SeriesPoint是由一个X坐标值和一个Y坐标值构成的，只要取得这个SeriesPoint就可以了。

Answer 1

是介于两个SeriesPoint之间的值，怎么取？

Answer 2

两个SeriesPoint之间的话，X就没有特定的值啊，怎么根据X的值取Y的值。

Answer 3

可以取到特定的值，如果这样设置，就能在ChartAreaS上看到一个十字线，从这个十字线上就可以同时取到X和Y的值。但我只想获得两个Series与红线交叉点的对应值。chart.ChartAreas[0].CursorX.IsUserEnabled = true;
chart.ChartAreas[0].CursorY.IsUserEnabled = true;

Answer 4

已经搞定，下面是代码：        /// <summary>
        /// Set Cursor Position to Edit control.
        /// </summary>
        /// <param name="e"></param>
        /// <param name="axis"></param>
        /// <param name="position"></param>
        private void SetPosition(CursorEventArgs e, Axis axis, double position)
        {
            if (double.IsNaN(position))
            {
                return;
            }            if (axis.AxisName == AxisName.X)
            {
                RefreshBoilerAndHeat();                DateTime dateTimeX = DateTime.FromOADate(position);
                this._chartControl.labInfo.Text = "时间： " + dateTimeX.ToString("yyyy-MM-dd HH:mm:ss") + "\n\n";                for (int i = 0; i < this._chartControl.chart.Series.Count; i++ )
                {
                    Series series = this._chartControl.chart.Series[i];
                    DataPoint lastPoint = null;
                    DataPoint nextPoint = null;
                        
                    for (int j = 0; j < series.Points.Count; j++)
                    {
                        DataPoint point = series.Points[j];
                        DateTime pointDateTime = DateTime.FromOADate(point.XValue);
                        TimeSpan ts = new TimeSpan();
                        ts = dateTimeX - pointDateTime;
                        if ((ts.TotalSeconds < 0 && j==0) || (ts.TotalSeconds >0 && j+1 == series.Points.Count))
                        {
                            break;
                        }                        if (ts.TotalSeconds < 0)
                        {
                            lastPoint = series.Points[j - 1];
                            nextPoint = point;
                            break;
                        }
                    }                    if (lastPoint == null && nextPoint == null)
                    {
                        this._chartControl.labInfo.Text = "时间：" + dateTimeX.ToString("yyyy-MM-dd HH:mm:ss") + "\n\n数值：";
                        break;
                    }
                    else
                    {
                        double diff = (nextPoint.YValues[0] - lastPoint.YValues[0]) / (nextPoint.XValue - lastPoint.XValue);
                        double yValue = diff * position - diff * lastPoint.XValue + lastPoint.YValues[0];
                        this._chartControl.labInfo.Text += series.Name + ": " + Math.Round(yValue,1).ToString() + "\n\n";
                    }
                }
            }
        }

Answer 5

DateTime dateTimeX = DateTime.FromOADate(position);
为什么能根据position拿到时间啊   能讲下原理吗   谢谢

Answer 6

我也遇到了，mousemove里怎么通过e.x获取到横坐标的值···

Answer 7

像素值转用户值
double yValue = chart_xxx.ChartAreas[x].AxisY.PixelPositionToValue(e.Y);