Question

我在Visual Studio中使用Windows窗体图表，我想编写一个函数，给定图表区域，轴返回最大值或最小值（XValue或Yvalue，具体取决于轴参数））从该图表区域的点。我想对第二个参数使用AxisName枚举，但是，按照惯例，msdn的官方documentation不会覆盖我。枚举名称是否表示ChartArea类的Axes（）属性的索引，还是指向Axis对象的直接链接？我需要在我的类中声明枚举（继承DataVisualisation.Charts），还是已经知道？请帮助我

Public Function getAxisMinimum(ByVal area As AreaEnum, ByVal axe As AxisName) As Double
  Dim min As Double = Double.NaN
  For Each ser As Series In Series
     If ser.ChartArea = ChartAreas(area).Name And ser.Points.Count > 0 Then
        For Each p As DataPoint In ser.Points
           'compare X or Y values depending on the axe argument to set the min
        Next
     End If
  Next
  'If there are no points in any series in the area, it will return NaN
  Return min

结束功能

AreaEnum是一个整数枚举，表示与每个名称对应的ChartArea（）属性的索引。

我不需要一个如何比较我的观点的解决方案。值或如何返回它们，我只需要解释如何使用AxisName枚举

Answer 1

没关系，我想我解决了。 Visual Studio的自动完成给了我答案，因为它识别了AxisName枚举并在select语句中纠正了我。我认为这有效：

Public Function getAxisMinimum(ByVal area As AreaEnum, ByVal axe As AxisName) As Double
  Dim min As Double = Double.NaN
  For Each ser As Series In Series
     If ser.ChartArea = ChartAreas(area).Name AndAlso ser.Points.Count > 0 Then
        For Each p As DataPoint In ser.Points
           Select Case axe
              Case AxisName.X
                 If Double.IsNaN(min) OrElse p.XValue < min Then
                    min = p.XValue
                 End If
              Case AxisName.Y
                 For Each Yval As Double In p.YValues
                    If Double.IsNaN(min) OrElse Yval < min Then
                       min = Yval
                    End If
                 Next
              Case Else
                 ' Not an acceptable AxisName
                 Return Double.NaN
           End Select
        Next
     End If
  Next
  'If there are no points in any series in the area, it will return NaN
  Return min

结束功能

AxisName枚举如何在Windows.Forms.Charts中工作？

1 个答案: