IComparer练习

Partial Class test_t_Compare
    Inherits System.Web.UI.Page

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

    End Sub

    Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim c As String = Me.DropDownList1.SelectedValue
        Dim b As Boolean = IIf(Me.DropDownList2.SelectedValue = "1", True, False)
        Dim list As List(Of TestSortData) = New List(Of TestSortData)
        list.Add(New TestSortData(1, 4, 3))
        list.Add(New TestSortData(1, 2, 1))
        list.Add(New TestSortData(1, 2, 3))
        list.Add(New TestSortData(5, 2, 3))
        list.Add(New TestSortData(3, 6, 3))
        list.Add(New TestSortData(3, 1, 3))
        list.Sort(New TestSortDataComparer(c, b))
        For Each item As TestSortData In list
            Response.Write(item.Clm1.ToString() + " - " + item.Clm2.ToString() + " - " + item.Clm3.ToString() + "<br>")
        Next
    End Sub


    Protected Sub Button3_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button3.Click
        Dim list As ArrayList = New ArrayList()
        list.Add("3")
        list.Add("2")
        list.Add("1")
        list.Sort()
        For Each item As String In list
            Response.Write(item + " - ")
        Next
    End Sub
End Class

Public Class TestSortData
    Private m_clm1 As Int32
    Private m_clm2 As Int32
    Private m_clm3 As Int32
    Public Sub New(ByVal c1 As Int32, ByVal c2 As Int32, ByVal c3 As Int32)
        m_clm1 = c1
        m_clm2 = c2
        m_clm3 = c3
    End Sub
    Public Property Clm1() As Int32
        Get
            Return m_clm1
        End Get
        Set(ByVal value As Int32)
            m_clm1 = value
        End Set
    End Property
    Public Property Clm2() As Int32
        Get
            Return m_clm2
        End Get
        Set(ByVal value As Int32)
            m_clm2 = value
        End Set
    End Property
    Public Property Clm3() As Int32
        Get
            Return m_clm3
        End Get
        Set(ByVal value As Int32)
            m_clm3 = value
        End Set
    End Property
End Class

Public Class TestSortDataComparer
    Implements IComparer(Of TestSortData)
    Private m_SortField As String
    Private m_IsAsc As Boolean
    Public Sub New(ByVal sort_field As String, Optional ByVal is_asc As Boolean = True)
        Me.m_SortField = sort_field
        Me.m_IsAsc = is_asc
    End Sub
    Public Function Compare(ByVal x As TestSortData, ByVal y As TestSortData) As Integer Implements System.Collections.Generic.IComparer(Of TestSortData).Compare
        Dim seq As Int32 = 1
        If Not Me.m_IsAsc Then seq = -1
        Select Case Me.m_SortField
            Case "C1"
                Dim rs21 As Int32 = x.Clm1.CompareTo(y.Clm1)
                If rs21 = 0 Then
                    Dim rs22 As Int32 = x.Clm2.CompareTo(y.Clm2)
                    If rs22 = 0 Then
                        Dim rs23 As Int32 = x.Clm3.CompareTo(y.Clm3)
                        If rs23 = 0 Then
                            Return 0
                        Else
                            Return rs23
                        End If
                    Else
                        Return rs22
                    End If
                Else
                    If rs21 > 0 Then rs21 = 1
                    If rs21 < 0 Then rs21 = -1
                    rs21 = rs21 * seq
                    Return rs21
                End If
            Case "C2"
　　　　　　..............
            Case "C3"
　　　　　　...............
        End Select

    End Function
End Class

转载于:https://www.cnblogs.com/liangzi_net/archive/2010/04/15/1712700.html