To take it one step further (this allows you to sort strings, dates and
numbers columns appropriately) Don't think I ever finished the
enumSortType.DateSort code completely... Not sure.
HTH,
Greg
in your form's class add:
' form level variable
Private lvwColumnSorter1 As ListViewColumnSorter
Public Sub New()
MyBase.New()
'This call is required by the Windows Form Designer.
InitializeComponent()
'Add any initialization after the InitializeComponent() call
' Create an instance of a ListView column sorter and assign it
' to the ListView control.
lvwColumnSorter1 = New ListViewColumnSorter
Me.lvw.ListViewItemSorter = lvwColumnSorter1
End Sub
Private Sub lvw_ColumnClick(ByVal sender As Object, ByVal e As
System.Windows.Forms.ColumnClickEventArgs) Handles lvw.ColumnClick
Select Case e.Column
Case TheNumericColumn -- sample custom enum for my columns...
lvwColumnSorter1.SortType =
ListViewColumnSorter.enumSortType.NumericSort
Case Else
lvwColumnSorter1.SortType =
ListViewColumnSorter.enumSortType.AlphaSort
End Select
' Determine if the clicked column is already the column that is
' being sorted.
If (e.Column = lvwColumnSorter1.SortColumn) Then
' Reverse the current sort direction for this column.
If (lvwColumnSorter1.Order = SortOrder.Ascending) Then
lvwColumnSorter1.Order = SortOrder.Descending
Else
lvwColumnSorter1.Order = SortOrder.Ascending
End If
Else
' Set the column number that is to be sorted; default to
ascending.
lvwColumnSorter1.SortColumn = e.Column
lvwColumnSorter1.Order = SortOrder.Ascending
End If
' Perform the sort with these new sort options.
Me.lvw.Sort()
End Sub
Add this helper class to project:
Imports System.Collections
Imports System.Windows.Forms
Public Class ListViewColumnSorter
Implements System.Collections.IComparer
Private ColumnToSort As Integer
Private OrderOfSort As SortOrder
Private ObjectCompare As CaseInsensitiveComparer
Private TypeOfSort As enumSortType
Enum enumSortType
AlphaSort
NumericSort
DateSort
End Enum
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 default column type to be Alpha.
TypeOfSort = enumSortType.AlphaSort
End Sub
Public Function Compare(ByVal x As Object, ByVal y As Object) As Integer
Implements IComparer.Compare
Dim compareResult As Integer
Dim listviewX As ListViewItem
Dim listviewY As ListViewItem
' Cast the objects to be compared to ListViewItem objects.
listviewX = CType(x, ListViewItem)
listviewY = CType(y, ListViewItem)
' Compare the two items.
Select Case TypeOfSort
Case enumSortType.AlphaSort, enumSortType.DateSort
compareResult =
ObjectCompare.Compare(listviewX.SubItems(ColumnToS ort).Text,
listviewY.SubItems(ColumnToSort).Text)
Case enumSortType.NumericSort
Dim intx As Integer =
CInt(listviewX.SubItems(ColumnToSort).Text)
Dim inty As Integer =
CInt(listviewY.SubItems(ColumnToSort).Text)
If intx = inty Then
compareResult = 0
ElseIf intx > inty Then
compareResult = 1
Else
compareResult = -1
End If
End Select
' Calculate the correct return value based on the object
' comparison.
If (OrderOfSort = SortOrder.Ascending) Then
' Ascending sort is selected, return typical 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 that they are equal.
Return 0
End If
End Function
Public Property SortColumn() As Integer
Set(ByVal Value As Integer)
ColumnToSort = Value
End Set
Get
Return ColumnToSort
End Get
End Property
Public Property Order() As SortOrder
Set(ByVal Value As SortOrder)
OrderOfSort = Value
End Set
Get
Return OrderOfSort
End Get
End Property
Public Property SortType() As enumSortType
Get
Return TypeOfSort
End Get
Set(ByVal Value As enumSortType)
TypeOfSort = Value
End Set
End Property
End Class
"Glenn Wilson" <Gl*********@discussions.microsoft.com> wrote in message
news:87**********************************@microsof t.com...
Class ListViewItemComparer
Implements IComparer
Private col As Integer
Public Sub New()
col = 0
End Sub
Public Sub New(ByVal column As Integer)
col = column
End Sub
Public Function Compare(ByVal x As Object, ByVal y As Object) As Integer
Implements IComparer.Compare Return [String].Compare(CType(x, ListViewItem).SubItems(col).Text,
CType(y, ListViewItem).SubItems(col).Text) End Function
End Class
Public Sub ColumnClick(ByVal sender As Object, ByVal e As
ColumnClickEventArgs) Handles listNumberList.ColumnClick
Me.listNumberList.ListViewItemSorter = New ListViewItemComparer(e.Column)
End Sub
"billuy" wrote:
Is there a way to sort by a specified column in a listview? I'd like my
users to be able to click on the column heading and have the listview sort
by that column.
Thanks,
Billyb
