VB.NET - Sort listview by any column
Steps to sort vb.net listview by any column (dates, ints, string or doubles)
#vbdotnet
Code:
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Public Class ListViewItemComparer
Implements IComparer
Private col As Integer
Private order As SortOrder
Public Sub New()
col = 0
order = SortOrder.Ascending
End Sub
Public Sub New(column As Integer, order As SortOrder)
col = column
Me.order = order
End Sub
Public Function Compare(x As Object, y As Object) As Integer Implements System.Collections.IComparer.Compare
Dim returnVal As Integer
Try
' Attempt to parse the two objects as DateTime
Dim firstDate As System.DateTime = DateTime.Parse(CType(x, ListViewItem).SubItems(col).Text)
Dim secondDate As System.DateTime = DateTime.Parse(CType(y, ListViewItem).SubItems(col).Text)
' Compare as date
returnVal = DateTime.Compare(firstDate, secondDate)
Catch ex As Exception
' If date parse failed then fall here to determine if objects are numeric
If IsNumeric(CType(x, ListViewItem).SubItems(col).Text) And
IsNumeric(CType(y, ListViewItem).SubItems(col).Text) Then
' Compare as numeric
returnVal = Val(CType(x, ListViewItem).SubItems(col).Text).CompareTo( _
Val(CType(y, ListViewItem).SubItems(col).Text))
Else
' If not numeric then compare as string
returnVal = [String].Compare(CType(x, _
ListViewItem).SubItems(col).Text, CType(y, ListViewItem).SubItems(col).Text)
End If
End Try
' If order is descending then invert value
If order = SortOrder.Descending Then
returnVal *= -1
End If
Return returnVal
End Function
End Class
' Value to track which column was previously sorted
Dim sortColumn as Integer = -1
Private Sub Listview1_ColumnClick(sender As Object, e As System.Windows.Forms.ColumnClickEventArgs) Handles Listview1.ColumnClick
' If current column is not the previously clicked column
' Add
If Not e.Column = sortColumn Then
' Set the sort column to the new column
sortColumn = e.Column
'Default to ascending sort order
Listview1.Sorting = SortOrder.Ascending
Else
'Flip the sort order
If Listview1.Sorting = SortOrder.Ascending Then
Listview1.Sorting = SortOrder.Descending
Else
Listview1.Sorting = SortOrder.Ascending
End If
End If
'Set the ListviewItemSorter property to a new ListviewItemComparer object
Me.Listview1.ListViewItemSorter = New ListViewItemComparer(e.Column, Listview1.Sorting)
' Call the sort method to manually sort
Listview1.Sort()
End Sub
End Class