如何在 Visual Basic 中在图表上绘制垂直线

Question

我是 Visual Basic 的初学者。我试图在图表的 X 轴上画一条垂直线，但找不到方法。请指教。

Private Sub Chart()

'Display Chart
Chart1.Series("ScoreChart").Points.Clear()
For xx As Integer = 0 To DataGridView4.RowCount - 1
    Me.Chart1.Series("ScoreChart").Points.AddXY(DataGridView4.Rows(xx).Cells(0).Value, DataGridView4.Rows(xx).Cells(DataGridView4.ColumnCount - 1).Value)
Next

结束子

Answer 1

可以参考以下代码添加垂直线。

    Dim verticalLine As VerticalLineAnnotation = New VerticalLineAnnotation()
    verticalLine.AxisX = Chart1.ChartAreas(0).AxisX
    verticalLine.IsInfinitive = True
    verticalLine.ClipToChartArea = Chart1.ChartAreas(0).Name
    verticalLine.LineColor = Color.Red
    verticalLine.LineWidth = 2
    verticalLine.X = 2
    Chart1.Annotations.Add(verticalLine)

结果如下：

Answer 2

使用下面的代码时，给出“AxisX”不是“Form1.VerticalLineAnnotation”成员的声明，下一步是什么

Dim verticalLine As VerticalLineAnnotation = New VerticalLineAnnotation()
verticalLine.AxisX = Chart1.ChartAreas(0).AxisX
verticalLine.IsInfinitive = True
verticalLine.ClipToChartArea = Chart1.ChartAreas(0).Name
verticalLine.LineColor = Color.Red
verticalLine.LineWidth = 2
verticalLine.X = 2
Chart1.Annotations.Add(verticalLine)