Question

当我绘制小于1的图表时，我的图表将崩溃（退出尝试）。有人知道为什么吗？带有正数，可以绘制出漂亮的图！我正在为其输入Double值，并且X和Y数据类型在属性中设置为“自动”。

如果值是正数，就可以了：

Dim dataStr As String =“ 1,2,3,4,5,6,7,8,9,10，*”

Dim dataStr As String = "-1,-2,-3,-4,-5,-6,-7,-8,-9,-10,*"
            Try
                Chart1.Series(0).Points.Clear()
                dataStr = dataStr.Replace(",*", "") ' Remove last comma and *
                Dim myArray = Array.ConvertAll(dataStr.Split(","c), AddressOf Convert.ToDouble)
                For Each point As Integer In myArray
                    Chart1.Series(0).Points.Add(myArray(point - 1))
                Next
            Catch
            End Try

Answer 1

更新：为避免在使用其他dataStr值（根据LarsTech注释）时出现异常，可以使用For循环，如下所示：

    Dim dataStr As String = "-1,-2,-3,-4,-5,-6,-7,-8,-9,-20,*"
    Try
        Chart1.Series(0).Points.Clear()
        dataStr = dataStr.Replace(",*", "") ' Remove last comma and *

        Dim myArray = Array.ConvertAll(dataStr.Split(","c), AddressOf Convert.ToDouble)
        Dim max As Integer = myArray.Length
        Dim i As Integer

        For i = 0 To max - 1
            Chart1.Series(0).Points.Add(myArray(i))
        Next
    Catch ex As Exception
        MsgBox(ex.Message)
    End Try

Answer 2

由于索引到负值，因此出现错误。您可以使用点变量的绝对值，如下所示。

    Dim dataStr As String = "-1,-2,-3,-4,-5,-6,-7,-8,-9,-10,*"

    Try
        Chart1.Series(0).Points.Clear()
        dataStr = dataStr.Replace(",*", "") ' Remove last comma and *
        Dim myArray = Array.ConvertAll(dataStr.Split(","c), AddressOf Convert.ToDouble)
        For Each point As Integer In myArray
           Chart1.Series(0).Points.Add(myArray(Math.Abs(point) - 1))
        Next
    Catch ex as exception
        MsgBox(ex.Message)
    End Try

VB.NET-图表无法绘制小于1的任何图形，例如：0，-1，-2

2 个答案: