列表集合中的最小值和最大值

Question

如何从此示例中获取最小值和最大值

Public Class RowsFound
    Property RowIndex As integer
    Property Qty As Integer
    Property LineValue As Double
End Class
Dim Test as new List(Of RowsFound)

上面你可以看到我列表的结构。这就是数据的样子。

根据最大 LineValue 和最小 LineValue 的 RowIndex 获取 RowIndex 的最佳方法是什么

我已经这样做了作为测试，但想看看是否有更好的方法。

                        Dim MaxRow As Integer = 0
                        Dim MaxRowValue As Integer = 0
                        Dim MinRow As Integer = 999999
                        Dim MinRowValue As Integer = 999999
                        For Each MinMaxitem As RowsFound In ListOfRows
                            If MinMaxitem.LineValue < MinRowValue Then
                                MinRow = MinMaxitem.RowIndex
                                MinRowValue = MinMaxitem.LineValue
                            End If
                            If MinMaxitem.LineValue > MaxRowValue Then
                                MaxRow = MinMaxitem.RowIndex
                                MaxRowValue = MinMaxitem.LineValue
                            End If
                        Next

谢谢:)

Answer 1

一个简单的方法是使用 LINQ：

Public Class RowsFound
    Property RowIndex As Integer
    Property Qty As Integer
    Property LineValue As Double
    Public Sub New(i As Integer, q As Integer, v As Double)
        Me.RowIndex = i
        Me.Qty = q
        Me.LineValue = v
    End Sub
End Class
Dim Test As New List(Of RowsFound) From {New RowsFound(0, 1, 105.25), New RowsFound(1, 2, 100), New RowsFound(2, 1, 110), New RowsFound(3, 2, 60.25)}


Dim RowIndexMax As Integer = (From row As RowsFound In Test.OrderByDescending(Function(x) x.LineValue) Select row.RowIndex).First
Dim RowindexMin As Integer = (From row As RowsFound In Test.OrderBy(Function(x) x.LineValue) Select row.RowIndex).First

Answer 2

您可以使用 Lambda 表达式：

先用Max()和Min()

LineValue

使用FindIndex()

查找所需值的索引

Private Function getMaxValueIndex() As Integer
Dim maxValue As Integer = Test.Max(Function(t) t.LineValue)
Dim maxValueIndex As Integer = Test.FindIndex(Function(t) t.LineValue = maxValue)
Return maxValueIndex
End Function

Private Function getMinValueIndex() As Integer
Dim minValue As Integer = Test.Min(Function(t) t.LineValue)
Dim minValueIndex As Integer = Test.FindIndex(Function(t) t.LineValue = minValue)
Return minValueIndex
End Function

列表集合中的最小值和最大值

Min and max from list collection

vb.net

ienumerable