图表控制Y轴自动缩放滚动

Question

我一直在寻找网络一段时间，但仍然没有找到任何好的解决方案，我的问题。我想让MS Chart在滚动时自动重新调整Y轴，以确保所有数据点都可见。这里的扭曲是我需要有能力排除某些系列被用于自动缩放。到目前为止，我只找到提供在AxisViewChanged事件上遍历整个点集合的解决方案，当您有大量点集合和一些系列迭代时，这种方法效果不佳。我想知道是否有任何方法通过获取当前可见的最小和最大X值之间的数据点来缩小搜索范围。任何帮助，将不胜感激。

编辑继承人的形象。正如你所看到的，中间的烛台并不完全可见。

Answer 1

你可以试试这个代码

 DateTime date = DateTime.Now; 
     chart1.ChartAreas[0].AxisX.Minimum = 0; 
     chart1.ChartAreas[0].AxisX.Maximum = 20; 
     Random r = new Random((int)date.Ticks); 

     chart1.Series[0].ChartType = SeriesChartType.Candlestick; 
     chart1.Series[0].Color = Color.Green; 
     chart1.Series[0].XValueType = ChartValueType.Time; 
     chart1.Series[0].IsXValueIndexed = true; 
     chart1.Series[0].YValuesPerPoint = 4; 
     chart1.Series[0].CustomProperties = "MaxPixelPointWidth=10"; 
     for (int i = 0; i < 100; i++) 
     { 
      DataPoint point = new DataPoint(date.AddHours(i).ToOADate(), new double[] { r.Next(10, 20), r.Next(30, 40), r.Next(20, 30), r.Next(20, 30) }); 
      chart1.Series[0].Points.Add(point); 
     } 

     int min = (int)chart1.ChartAreas[0].AxisX.Minimum; 
     int max = (int)chart1.ChartAreas[0].AxisX.Maximum; 

     if (max > chart1.Series[0].Points.Count) 
      max = chart1.Series[0].Points.Count; 

     var points = chart1.Series[0].Points.Skip(min).Take(max - min); 

     var minValue = points.Min(x => x.YValues[0]); 
     var maxValue = points.Max(x => x.YValues[1]); 

     chart1.ChartAreas[0].AxisY.Minimum = minValue; 
     chart1.ChartAreas[0].AxisY.Maximum = maxValue; 

Answer 2

使用查询来找出你要使用的代码中发现y最小和y哪个系列。

private void chart1_AxisViewChanged(object sender, ViewEventArgs e) 
    { 
     if (e.Axis.AxisName == AxisName.X) 
     { 
      int start = (int)e.Axis.ScaleView.ViewMinimum; 
      int end = (int)e.Axis.ScaleView.ViewMaximum; 

      // Series ss = chart1.Series.FindByName("SeriesName"); 
      // use ss instead of chart1.Series[0] 

      double[] temp = chart1.Series[0].Points.Where((x, i) => i >= start && i <= end).Select(x => x.YValues[0]).ToArray(); 
      double ymin = temp.Min(); 
      double ymax = temp.Max(); 

      chart1.ChartAreas[0].AxisY.ScaleView.Position = ymin; 
      chart1.ChartAreas[0].AxisY.ScaleView.Size = ymax - ymin; 
     } 
    } 

Answer 3

这是从Shivaram Kr的优良提交一个小的改进，以防止打开，关闭和低脱落的最低点底部与四个Y值金融图表：高，低，打开关闭。

// The following line goes in your form constructor 
this.chart1.AxisViewChanged += new EventHandler<ViewEventArgs> (this.chart1_AxisViewChanged); 


private void chart1_AxisViewChanged(object sender, ViewEventArgs e) 
{ 
    if (e.Axis.AxisName == AxisName.X) 
    { 
     int start = (int)e.Axis.ScaleView.ViewMinimum; 
     int end = (int)e.Axis.ScaleView.ViewMaximum; 
     // Use two separate arrays, one for highs (same as temp was in Shavram's original) 
     // and a new one for lows which is used to set the Y axis min. 
     double[] tempHighs = chart1.Series[0].Points.Where((x, i) => i >= start && i <= end).Select(x => x.YValues[0]).ToArray(); 
     double[] tempLows = chart1.Series[0].Points.Where((x, i) => i >= start && i <= end).Select(x => x.YValues[1]).ToArray(); 
     double ymin = tempLows.Min(); 
     double ymax = tempHighs.Max(); 

     chart1.ChartAreas[0].AxisY.ScaleView.Position = ymin; 
     chart1.ChartAreas[0].AxisY.ScaleView.Size = ymax - ymin; 
    } 
} 

Answer 4

基于以前的答案

private void chart1_AxisViewChanged(object sender, ViewEventArgs e) 
    { 
     if(e.Axis.AxisName == AxisName.X) 
     { 
      int start = (int)e.Axis.ScaleView.ViewMinimum; 
      int end = (int)e.Axis.ScaleView.ViewMaximum; 

      List<double> allNumbers = new List<double>(); 

      foreach(Series item in chart1.Series) 
       allNumbers.AddRange(item.Points.Where((x, i) => i >= start && i <= end).Select(x => x.YValues[0]).ToList()); 

      double ymin = allNumbers.Min(); 
      double ymax = allNumbers.Max(); 

      chart1.ChartAreas[0].AxisY.ScaleView.Position = ymin; 
      chart1.ChartAreas[0].AxisY.ScaleView.Size = ymax - ymin; 
     } 
    } 

这可能是你在chartarea更多的系列。在这种情况下，您可以选择该区域所有系列的高位和低位，而不是一个。

问候，

Matthijs

Answer 5

以上回答对我来说非常有帮助。但是，我有一个包含多个图表区域的图表。我已调整代码以扩大到所有图表区域：

foreach (ChartArea area in chart1.ChartAreas) 
    { 
     List<double> allNumbers = new List<double>(); 

     foreach (Series item in chart1.Series) 
     if (item.ChartArea == area.Name) 
      allNumbers.AddRange(item.Points.Where((x, i) => i >= start && i <= end).Select(x => x.YValues[0]).ToList()); 

     double ymin = allNumbers.Min(); 
     double ymax = allNumbers.Max(); 

     if (ymax > ymin) 
     { 
     double offset = 0.02 * (ymax - ymin); 
     area.AxisY.Maximum = ymax + offset; 
     area.AxisY.Minimum = ymin - offset; 
     } 
    }