Question

我有一个数组s()，如下所示，我想根据值s().Mean对数组进行排序，值最高或最低，反之亦然。我是VB.NET的新手，所以对任何解决方案都感兴趣。我将所有平均值复制到一个简单的数组中，并尝试执行Array.Sort(s,Compare)，但收到一条ICompare错误消息，因此现在对下一步操作有些迷茫。

Public Class Form1

    Public Structure Values

        Public DateTime As String
        Public Value As Double

    End Structure

    Public Structure QDAS

        Public Index As Integer
        Public ID As String
        Public Description As String
        Public PartType As String
        Public Operation As String
        Public Status As Boolean
        Public Mean As Double
        Public Nominal As Double
        Public USL As Double
        Public LSL As Double
        Public Deviation As Double
        Public ErrorAfterTol As Double
        Public Max As Double
        Public Min As Double
        Public Range As Double
        Public TotalTolerance As Double
        Public PercentOfTol As Double
        Public Repeatability As Double
        Public Units As String
        Public Values() As Values


    End Structure

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click

        Dim s(5) As QDAS

        Dim i

        For i = 0 To 5

            s(i).Description = "F" & i
            ReDim Preserve s(i).Values(5)

            For j = 0 To 5
                s(i).Values(j).Value = Rnd()
            Next

            For j = 0 To UBound(s(i).Values)
                s(i).Mean = s(i).Mean + s(i).Values(j).Value
            Next

            s(i).Mean = s(i).Mean / (UBound(s(i).Values) + 1)

        Next


        MsgBox("Done")

        Dim Compare() As Double = Nothing

        ReDim Compare(UBound(s))

        For i = 0 To UBound(s)

            Compare(i) = s(i).Mean
        Next

        Array.Sort(s, Compare)

    End Sub
End Class

Answer 1

您正在使用的Array.Sort的重载假定第一个参数是您要排序的键数组，第二个参数是您要排序的值数组。

只需反转参数即可：

' Sort low-to-high
Array.Sort(Compare, s)

或

' Sort high-to-low
For i = 0 To UBound(s)
    Compare(i) = -s(i).Mean
Next
Array.Sort(Compare, s)

如果您熟悉Object Initializers，Lambda Expressions和LINQ等更高级的主题，则可以将Button1_Click处理程序简化为：

Dim CreateQDAS As Func(Of Integer, QDAS) = _
    Function (i As Integer) New QDAS With {
        .Values = Enumerable.Range(0, 5).Select(Function (j) New Values With { .Value = Rnd() }).ToArray(),
        .Mean = .Values.Average(Function (v) v.Value)
    }

Dim s = Enumerable.Range(0, 5).Select(CreateQDAS)
' Sort low-to-high
Dim Sorted = s.OrderBy(Function (item) item.Mean)

或

' Sort high-to-low
Dim Sorted = s.OrderByDescending(Function (item) item.Mean)

对基于结构的数组进行排序

1 个答案: