How do I sort a listview control

  • Thread starter Thread starter James L
  • Start date Start date
J

James L

I am trying to sort a listview control by subitem in ascending and
descending order. I followed the instructions in the Visual Studio
help. They are very explicit and detailed, but unfortuntely it does
not work. Is the help applicable to VB.NET compactframework or only to
desktop VB.NET?

First:

The help says to "add the following line to the forms constructor":

Addhandler listview.columnclick address of me.listview_columnclick

I am unlcear where I am supposed to place this line. If I place it in
the ColumnClick event of the listview it shows no errors but is that
the correct place? Does it belong in the columnclick event, or
elsewhere?

Second:
In the code window VisualStudio underlines certain items and gives me
error warnings with them. Those warnings are:

me.listview.sorting.....
'Sorting' is not a member of 'System.windows.forms.listview'

sortorder.ascending
Name SortOrder is not declared

me.listview.sort.....
'Sort' is not a member of 'System.windows.forms.listview'

me.listview.ListViewItemSorter.....
ListViewItemSorter is not a member 'System.windows.forms.listview'

I understand what the errors mean, these properties do not exist for
the listview control. But if they do not exist, why does the help tell
me to use them? Is there another system item I should be importing
that I might have missed in the Imports lines? Currently I have:

Imports System
Imports System.io
Imports System.Reflection


James Lysaght
 
OK
I checked the archives and from there I read the quickstart tutorial. I
duplicated the code from the tutorial, thinking I understood it fairly well,
and modified as necessary such as changing the name of the listview control
to the name I used for my listview control.

On the following line:
Dim clickedCol As ColHeader = CType(Me.lvwItemList.Columns(e.Column),
ColHeader)

I get this error:

An unhandled exception of type 'System.InvalidCastException' occurred in
testprogram.exe

What the heck does that mean?



ColHeader is defined with the following code:

Public Class ColHeader

Inherits ColumnHeader

Public ascending As Boolean

Public Sub New(ByVal [text] As String, ByVal width As Integer, ByVal
align As HorizontalAlignment, ByVal asc As Boolean)

Me.Text = [text]

Me.Width = width

Me.TextAlign = align

Me.ascending = asc

End Sub

End Class



James
 
Assuming lvwItemList is a ListView, Me.lvwItemList.Columns(e.Column) returns
a ColumnHeader - not ColHeader.

Cheers
Daniel
--
http://www.danielmoth.com/Blog/


JamesL said:
OK
I checked the archives and from there I read the quickstart tutorial. I
duplicated the code from the tutorial, thinking I understood it fairly
well, and modified as necessary such as changing the name of the listview
control to the name I used for my listview control.

On the following line:
Dim clickedCol As ColHeader = CType(Me.lvwItemList.Columns(e.Column),
ColHeader)

I get this error:

An unhandled exception of type 'System.InvalidCastException' occurred in
testprogram.exe

What the heck does that mean?



ColHeader is defined with the following code:

Public Class ColHeader

Inherits ColumnHeader

Public ascending As Boolean

Public Sub New(ByVal [text] As String, ByVal width As Integer,
ByVal align As HorizontalAlignment, ByVal asc As Boolean)

Me.Text = [text]

Me.Width = width

Me.TextAlign = align

Me.ascending = asc

End Sub

End Class



James

I am trying to sort a listview control by subitem in ascending and
descending order. I followed the instructions in the Visual Studio
help. They are very explicit and detailed, but unfortuntely it does
not work. Is the help applicable to VB.NET compactframework or only to
desktop VB.NET?

First:

The help says to "add the following line to the forms constructor":

Addhandler listview.columnclick address of me.listview_columnclick

I am unlcear where I am supposed to place this line. If I place it in
the ColumnClick event of the listview it shows no errors but is that
the correct place? Does it belong in the columnclick event, or
elsewhere?

Second:
In the code window VisualStudio underlines certain items and gives me
error warnings with them. Those warnings are:

me.listview.sorting.....
'Sorting' is not a member of 'System.windows.forms.listview'

sortorder.ascending
Name SortOrder is not declared

me.listview.sort.....
'Sort' is not a member of 'System.windows.forms.listview'

me.listview.ListViewItemSorter.....
ListViewItemSorter is not a member 'System.windows.forms.listview'

I understand what the errors mean, these properties do not exist for
the listview control. But if they do not exist, why does the help tell
me to use them? Is there another system item I should be importing
that I might have missed in the Imports lines? Currently I have:

Imports System
Imports System.io
Imports System.Reflection


James Lysaght
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