Imports System.Windows.Forms

Public Class ListViewColumnSorter
  Implements IComparer
  ' Specifies the column to be sorted
  Private ColumnToSort As Integer
  ' Specifies the order in which to sort (i.e. 'Ascending').
  Private OrderOfSort As SortOrder
  ' Case insensitive comparer object
  Private ObjectCompare As CaseInsensitiveComparer

  ' Class constructor.  Initializes various elements
  Public Sub New()
    ' Initialize the column to '0'
    ColumnToSort = 0
    ' Initialize the sort order to 'none'
    OrderOfSort = SortOrder.None
    ' Initialize the CaseInsensitiveComparer object
    ObjectCompare = New CaseInsensitiveComparer()
  End Sub

  ' This method is inherited from the IComparer interface.
  ' It compares the two objects passed using a case insensitive comparison.
  ' <param name="x">First object to be compared</param>
  ' <param name="y">Second object to be compared</param>
  ' <returns>The result of the comparison. "0" if equal,
  ' negative if 'x' is less than 'y' and positive if 'x' is greater than 'y'</returns>
  Public Function Compare(ByVal x As Object, ByVal y As Object) As Integer _
    Implements IComparer.Compare
    Dim compareResult As Integer
    Dim listviewX, listviewY As ListViewItem

    ' Cast the objects to be compared to ListViewItem objects
    listviewX = CType(x, ListViewItem)
    listviewY = CType(y, ListViewItem)

    ' Compare the two items
    compareResult = ObjectCompare.Compare(listviewX.SubItems(ColumnToSort).Text,
                                          listviewY.SubItems(ColumnToSort).Text)

    ' Calculate correct return value based on object comparison
    If (OrderOfSort = SortOrder.Ascending) Then
      ' Ascending sort is selected, return normal result of compare operation
      Return compareResult
    ElseIf (OrderOfSort = SortOrder.Descending) Then
      ' Descending sort is selected, return negative result of compare operation
      Return (-compareResult)
    Else
      ' Return '0' to indicate they are equal
      Return 0
    End If
  End Function

  ' Gets or sets the number of the column to which to apply the sorting operation (Defaults to '0').
  Public Property SortColumn() As Integer
    Set(ByVal value As Integer)
      ColumnToSort = value
    End Set
    Get
      Return ColumnToSort
    End Get
  End Property

  ' Gets or sets the order of sorting to apply (for example, 'Ascending' or 'Descending').
  Public Property Order As SortOrder
    Set(ByVal value As SortOrder)
      OrderOfSort = value
    End Set
    Get
      Return OrderOfSort
    End Get
  End Property

End Class

  Private Sub ListView1_ColumnClick(sender As Object, e As ColumnClickEventArgs) Handles ListView1.ColumnClick
 
    Dim SK As Integer = lvwColumnSorter.SortColumn 'запоминаем предыдущий ключ сортировки
    If e.Column = Column_Icon.Index Then Exit Sub 'сортировку по иконке не производим
    If (SK = e.Column) Then 'ключ сортировки не меняется,меняем порядок сортировки
      If lvwColumnSorter.Order = SortOrder.Ascending Then
        lvwColumnSorter.Order = SortOrder.Descending
        'установка иконки "Descending"
        ...
       Else
        lvwColumnSorter_Inbox.Order = SortOrder.Ascending
        'установка иконки "Ascending"
         ...
    Else 'если ключ сортировки меняется, порядок сортировки делаем по возрастанию
      lvwColumnSorter.Order = SortOrder.Ascending
      lvwColumnSorter.SortColumn = e.Column
      'удаление предыдущей иконки
      'установка иконки "Ascending"
        ...
     End If
    ListView1.Sort()
  End Sub

Imports System.Windows.Forms

Public Class ListViewColumnSorter
  Implements IComparer

  Public Enum eSortTypeConstants
    [stString] = 0
    [stStringSensitive] = 1
    [stNumeric] = 2
    [stDate] = 3
  End Enum

  ' Specifies the column to be sorted
  Private ColumnToSort As Integer
  ' Specifies the order in which to sort (i.e. 'Ascending').
  Private OrderOfSort As SortOrder
  ' Case insensitive comparer object
  Private ObjectCompare As CaseInsensitiveComparer
  ' Sort Type
  Private TypeOfSort As eSortTypeConstants

  ' Class constructor.  Initializes various elements
  Public Sub New()
    ' Initialize the column to '0'
    ColumnToSort = 0
    ' Initialize the sort order to 'none'
    OrderOfSort = SortOrder.None
    ' Initialize the CaseInsensitiveComparer object
    ObjectCompare = New CaseInsensitiveComparer()
    ' Initialize the sort type to [stString]'
    TypeOfSort = eSortTypeConstants.stString
  End Sub

  Public Sub New(ByVal column As Integer, ByVal order As SortOrder, Optional ByVal type As eSortTypeConstants = eSortTypeConstants.stString)
    ColumnToSort = column
    OrderOfSort = order
    TypeOfSort = type
    ObjectCompare = New CaseInsensitiveComparer()
  End Sub

  ' This method is inherited from the IComparer interface.
  ' It compares the two objects passed using a case insensitive comparison.
  ' <param name="x">First object to be compared</param>
  ' <param name="y">Second object to be compared</param>
  ' <returns>The result of the comparison. "0" if equal,
  ' negative if 'x' is less than 'y' and positive if 'x' is greater than 'y'</returns>
  Public Function Compare(ByVal x As Object, ByVal y As Object) As Integer _
    Implements IComparer.Compare
    Dim compareResult As Integer
    Dim listviewX, listviewY As ListViewItem

    ' Cast the objects to be compared to ListViewItem objects
    listviewX = CType(x, ListViewItem)
    listviewY = CType(y, ListViewItem)

    ' Compare the two items
    If TypeOfSort = eSortTypeConstants.stDate Then
      compareResult = DateTime.Compare(DateFromString(listviewX.SubItems(ColumnToSort).Text),
                                       DateFromString(listviewY.SubItems(ColumnToSort).Text))
    Else
      compareResult = ObjectCompare.Compare(listviewX.SubItems(ColumnToSort).Text,
                                            listviewY.SubItems(ColumnToSort).Text)
    End If

    ' Calculate correct return value based on object comparison
    If (OrderOfSort = SortOrder.Ascending) Then
      ' Ascending sort is selected, return normal result of compare operation
      Return compareResult
    ElseIf (OrderOfSort = SortOrder.Descending) Then
      ' Descending sort is selected, return negative result of compare operation
      Return (-compareResult)
    Else
      ' Return '0' to indicate they are equal
      Return 0
    End If
  End Function

  ' Gets or sets the number of the column to which to apply the sorting operation (Defaults to '0').
  Public Property SortColumn() As Integer
    Set(ByVal value As Integer)
      ColumnToSort = value
    End Set
    Get
      Return ColumnToSort
    End Get
  End Property

  ' Gets or sets the order of sorting to apply (for example, 'Ascending' or 'Descending').
  Public Property Order As SortOrder
    Set(ByVal value As SortOrder)
      OrderOfSort = value
    End Set
    Get
      Return OrderOfSort
    End Get
  End Property

  ' Gets or sets the type of sorting to apply (for example, '[stString]' or '[stDate]').
  Public Property SortType As eSortTypeConstants
    Set(ByVal value As eSortTypeConstants)
      TypeOfSort = value
    End Set
    Get
      Return TypeOfSort
    End Get
  End Property

End Class