在图表控件上显示鼠标轴坐标

Question

有没有一种简单的方法来检索图表区域中任何点的 X/Y 坐标（当然是相对于该图表轴）？

到目前为止，我只是在鼠标位于系列（而不是外部）上时设法检索坐标

private void chart_GetToolTipText(object sender, ToolTipEventArgs e)
{
    if (e.HitTestResult.Series != null)
    {
        e.Text = e.HitTestResult.Series.Points[e.HitTestResult.PointIndex].YValues[0] + " \n " + DateTime.FromOADate(e.HitTestResult.Series.Points[e.HitTestResult.PointIndex].XValue);
    }
}

Answer 1

无论如何，与 MS Chart Controls 一样，没有简单的方法来做事情，
但是一个时髦的解决方法可以完成事情。可惜我已经习惯了……

private void chart1_MouseWhatever(object sender, MouseEventArgs e)
{
    chartArea1.CursorX.SetCursorPixelPosition(new Point(e.X, e.Y), true);
    chartArea1.CursorY.SetCursorPixelPosition(new Point(e.X, e.Y), true);

    double pX = chartArea1.CursorX.Position; //X Axis Coordinate of your mouse cursor
    double pY = chartArea1.CursorY.Position; //Y Axis Coordinate of your mouse cursor
}

Answer 2

这适用于我的目的，不会影响光标。

private Tuple<double,double> GetAxisValuesFromMouse(int x, int y)
{
    var chartArea = _chart.ChartAreas[0];
    var xValue = chartArea.AxisX.PixelPositionToValue(x);
    var yValue = chartArea.AxisY.PixelPositionToValue(y);
    return new Tuple<double, double>(xValue, yValue);
}

Answer 3

我试过你的答案，但它对我不起作用。它最终将光标放在一个位置并且从不移动。我相信这是因为我在两个轴上都使用十进制/双精度值，并且光标正在四舍五入到最接近的整数。

经过几次尝试，我找到了一种方法来确定光标在图表中的位置。困难的部分是弄清楚图表元素的所有“位置”实际上都是百分比值（从 0 到 100）。

根据
http://msdn.microsoft.com/en-us/library/system.windows.forms.datavisualization.charting.elementposition.aspx:
“定义图表元素在相对坐标中的位置，范围从 (0,0) 到 (100,100)。”

我希望你不介意，我在这里发布这个答案只是为了后代，以防其他人遇到这个问题，而你的方法也不适用于他们。它在任何方面都不漂亮或优雅，但到目前为止它对我有用。

private struct PointD
{
  public double X;
  public double Y;
  public PointD(double X, double Y)
  {
    this.X = X;
    this.Y = Y;
  }
}

private void chart1_MouseMove(object sender, MouseEventArgs e)
{
  var pos = LocationInChart(e.X, e.Y);
  lblCoords.Text = string.Format("({0}, {1}) ... ({2}, {3})", e.X, e.Y, pos.X, pos.Y);
}

private PointD LocationInChart(double xMouse, double yMouse)
{
  var ca = chart1.ChartAreas[0];

  //Position inside the control, from 0 to 100
  var relPosInControl = new PointD
  (
    ((double)xMouse / (double)execDetailsChart.Width) * 100,
    ((double)yMouse / (double)execDetailsChart.Height) * 100
  );

  //Verify we are inside the Chart Area
  if (relPosInControl.X < ca.Position.X || relPosInControl.X > ca.Position.Right
  || relPosInControl.Y < ca.Position.Y || relPosInControl.Y > ca.Position.Bottom) return new PointD(double.NaN, double.NaN);

  //Position inside the Chart Area, from 0 to 100
  var relPosInChartArea = new PointD
  (
    ((relPosInControl.X - ca.Position.X) / ca.Position.Width) * 100,
    ((relPosInControl.Y - ca.Position.Y) / ca.Position.Height) * 100
  );

  //Verify we are inside the Plot Area
  if (relPosInChartArea.X < ca.InnerPlotPosition.X || relPosInChartArea.X > ca.InnerPlotPosition.Right
  || relPosInChartArea.Y < ca.InnerPlotPosition.Y || relPosInChartArea.Y > ca.InnerPlotPosition.Bottom) return new PointD(double.NaN, double.NaN);

  //Position inside the Plot Area, 0 to 1
  var relPosInPlotArea = new PointD
  (
    ((relPosInChartArea.X - ca.InnerPlotPosition.X) / ca.InnerPlotPosition.Width),
    ((relPosInChartArea.Y - ca.InnerPlotPosition.Y) / ca.InnerPlotPosition.Height)
  );

  var X = relPosInPlotArea.X * (ca.AxisX.Maximum - ca.AxisX.Minimum) + ca.AxisX.Minimum;
  var Y = (1 - relPosInPlotArea.Y) * (ca.AxisY.Maximum - ca.AxisY.Minimum) + ca.AxisY.Minimum;

  return new PointD(X, Y);
}

Answer 4

private void OnChartMouseMove(object sender, MouseEventArgs e)
{
    var sourceChart = sender as Chart;
    HitTestResult result = sourceChart.HitTest(e.X, e.Y);
    ChartArea chartAreas = sourceChart.ChartAreas[0];

    if (result.ChartElementType == ChartElementType.DataPoint)  
    {
        chartAreas.CursorX.Position = chartAreas.AxisX.PixelPositionToValue(e.X);
        chartAreas.CursorY.Position = chartAreas.AxisY.PixelPositionToValue(e.Y);
    }
}

Answer 5

这行得通

private void chart1_MouseWhatever(object sender, MouseEventArgs e)
{   
    Point chartLocationOnForm = chart1.FindForm().PointToClient(chart1.Parent.PointToScreen(chart1.Location));     

    double x = chart1.ChartAreas[0].AxisX.PixelPositionToValue(e.X - chartLocationOnForm.X);    
    double y = chart1.ChartAreas[0].AxisY.PixelPositionToValue(e.Y - chartLocationOnForm.Y);
}

这行得通

private void chart1_MouseWhatever(object sender, MouseEventArgs e)
{ 
    Point chartLocationOnForm = chart1.FindForm().PointToClient(chart1.Parent.PointToScreen(chart1.Location));                

    chart1.ChartAreas[0].CursorX.SetCursorPixelPosition(new PointF(e.X - chartLocationOnForm.X, e.Y - chartLocationOnForm.Y), true);
    chart1.ChartAreas[0].CursorY.SetCursorPixelPosition(new PointF(e.X - chartLocationOnForm.X, e.Y - chartLocationOnForm.Y), true);

    double x = chart1.ChartAreas[0].CursorX.Position;
    double y = chart1.ChartAreas[0].CursorY.Position;
}

Answer 6

这就是我得到的，我认为我们中的许多人都在同一条线上，但对您要寻找的东西有不同的解释。

这将为您提供绘图区域中任何位置的坐标。我发现HitTest 提供了一个简洁明了的解决方案，但是需要进行一些检查，无论光标是在数据点、网格线上还是在绘图区域（似乎按此顺序优先）。我假设您会对坐标感兴趣，无论鼠标在哪个对象上。

private void chart_GetToolTipText(object sender, ToolTipEventArgs e)
{
    // If the mouse isn't on the plotting area, a datapoint, or gridline then exit
    HitTestResult htr = chart.HitTest(e.X, e.Y);
    if (htr.ChartElementType != ChartElementType.PlottingArea && htr.ChartElementType != ChartElementType.DataPoint && htr.ChartElementType != ChartElementType.Gridlines)
        return;

    ChartArea ca = chart.ChartAreas[0]; // Assuming you only have 1 chart area on the chart

    double xCoord = ca.AxisX.PixelPositionToValue(e.X);
    double yCoord = ca.AxisY.PixelPositionToValue(e.Y);

    e.Text = "X = " + Math.Round(xCoord, 2).ToString() + "\nY = " + Math.Round(yCoord, 2).ToString();
}

Answer 7

VB.net 版本，带缩放校正：

Private Function LocationInChart(xMouse, yMouse) As PointF
    Dim ca = Chart1.ChartAreas(0)

    'Position inside the control, from 0 to 100
    Dim relPosInControl = New PointF((xMouse / Chart1.Width) * 100, (yMouse / Chart1.Height) * 100)

    'Verify we are inside the Chart Area
    If (relPosInControl.X < ca.Position.X Or relPosInControl.X > ca.Position.Right Or relPosInControl.Y < ca.Position.Y Or relPosInControl.Y > ca.Position.Bottom) Then Return New PointF(Double.NaN, Double.NaN)

    'Position inside the Chart Area, from 0 to 100
    Dim relPosInChartArea = New PointF(((relPosInControl.X - ca.Position.X) / ca.Position.Width) * 100, ((relPosInControl.Y - ca.Position.Y) / ca.Position.Height) * 100)

    'Verify we are inside the Plot Area
    If (relPosInChartArea.X < ca.InnerPlotPosition.X Or relPosInChartArea.X > ca.InnerPlotPosition.Right Or relPosInChartArea.Y < ca.InnerPlotPosition.Y Or relPosInChartArea.Y > ca.InnerPlotPosition.Bottom) Then Return New PointF(Double.NaN, Double.NaN)

    'Position inside the Plot Area, 0 to 1
    Dim relPosInPlotArea = New PointF(((relPosInChartArea.X - ca.InnerPlotPosition.X) / ca.InnerPlotPosition.Width), ((relPosInChartArea.Y - ca.InnerPlotPosition.Y) / ca.InnerPlotPosition.Height))

    Dim X = relPosInPlotArea.X * (ca.AxisX.Maximum - ca.AxisX.Minimum) + ca.AxisX.Minimum
    Dim Y = (1 - relPosInPlotArea.Y) * (ca.AxisY.Maximum - ca.AxisY.Minimum) + ca.AxisY.Minimum

    ' zoomo korekcija
    Dim zoomx = (ca.AxisX.ScaleView.ViewMaximum - ca.AxisX.ScaleView.ViewMinimum) / (ca.AxisX.Maximum - ca.AxisX.Minimum)
    Dim zoomy = (ca.AxisY.ScaleView.ViewMaximum - ca.AxisY.ScaleView.ViewMinimum) / (ca.AxisY.Maximum - ca.AxisY.Minimum)
    Dim xx = ca.AxisX.ScaleView.ViewMinimum + X * zoomx
    Dim yy = ca.AxisY.ScaleView.ViewMinimum + Y * zoomy

    Return New PointF(xx, yy)
End Function