List view sort arrow vb.net - vb.net

Question

i am trying to draw sort arrows on list view column header along with the default visual styles
so far i have got this
Private Sub List_DrawColumnHeader(sender As Object, e As DrawListViewColumnHeaderEventArgs) Handles List.DrawColumnHeader
e.DrawDefault = True
If e.ColumnIndex = selectedIndex Then
e.Graphics.DrawImage(ImageList1.Images(1), CType(e.Bounds.Left + e.Bounds.Width / 2, Single) - 5, -2)
End If
End Sub
but the visual style is drawn over the arrow somehow
so i figured i could try this :
Private Sub List_DrawColumnHeader(sender As Object, e As DrawListViewColumnHeaderEventArgs) Handles List.DrawColumnHeader
e.DrawDefault = True
If lastDrawn.ColumnIndex = selectedIndex Then
e.Graphics.DrawImage(ImageList1.Images(1), CType(lastDrawn.Bounds.Left + lastDrawn.Bounds.Width / 2, Single) - 5, -2)
End If
lastDrawn=e
End Sub
and it draws the arrow when the next corresponding column is being drawn
but with this i cant get it to draw for the last column
Screenshots:

Answer 1

In order to use the .NET build in solution for showing a custom icon for a list view column header you need to:
create an ImageList
add three images (up / down arrow and empty) to it
bind the image list to the ListView control
bind to the ColumnClick event of the ListView control
when sorting the columns set the ImageKey property of the currently sorted column depending on the sorting direction
This example class (a simple form) shows how to set the images correctly not using custom drawing for the ListView header columns.
It does not implement any sort! (how to implement a ListViewSorter is shown in this MSDN article)
You need to implement a custom ListView-Sorter class and retrieve the image or the image key from it, after a column is sorted.
Public Class SimpleForm
Inherits Form
Private sortItems = New ImageList()
Dim lv As ListView = New ListView()
Dim so = System.Windows.Forms.SortOrder.Ascending
Public Sub New()
' create columns, items and ListView
Dim columns = New List(Of ColumnHeader)
Dim c1 = New ColumnHeader()
c1.Name = "c1"
c1.Text = "Name"
Dim c2 = New ColumnHeader()
c2.Name = "c2"
c2.Text = "Type"
columns.Add(c1)
columns.Add(c2)
Dim items = New List(Of ListViewItem)
Dim i1 = New ListViewItem("Terminator")
i1.SubItems.Add("T1000")
Dim i2 = New ListViewItem("Terminator")
i2.SubItems.Add("T10")
Dim i3 = New ListViewItem("J.C.")
i3.SubItems.Add("Human")
items.Add(i1)
items.Add(i2)
items.Add(i3)
' init and bind column click
lv.Columns.AddRange(columns.ToArray())
lv.Items.AddRange(items.ToArray())
lv.SmallImageList = sortItems
lv.View = View.Details
lv.Dock = DockStyle.Fill
Controls.Add(lv)
AddHandler lv.ColumnClick, AddressOf clickEventHandler
' init images list
sortItems.TransparentColor = System.Drawing.Color.Transparent
sortItems.Images.Add("up", Image.FromFile("d:\temp\32\arrow_up.gif"))
sortItems.Images.Add("down", Image.FromFile("d:\temp\32\arrow_down.gif"))
sortItems.Images.Add("empty", Image.FromFile("d:\temp\32\check.gif"))
End Sub
Private Sub clickEventHandler(ByVal o As Object, ByVal e As ColumnClickEventArgs)
' Implement a custom ListViewItemSorter and fetch the icon from it!
' Set the ListViewItemSorter property to a new ListViewItemComparer
' object. Setting this property immediately sorts the
' ListView using the ListViewItemComparer object.
' THIS CODE SHOWS ONLY HOW TO SET THE SORT ICON!
For i As Integer = 0 To lv.Columns.Count - 1
If (i = e.Column) Then
Select Case (so)
Case System.Windows.Forms.SortOrder.Ascending
lv.Columns(i).ImageKey = "up"
so = System.Windows.Forms.SortOrder.Descending
Case System.Windows.Forms.SortOrder.Descending
lv.Columns(i).ImageKey = "down"
so = System.Windows.Forms.SortOrder.Ascending
Case Else
lv.Columns(i).ImageKey = "empty"
so = System.Windows.Forms.SortOrder.None
End Select
Else
lv.Columns(i).ImageKey = "empty"
End If
Next i
End Sub
End Class
The output looks like this: