Get ValueMember of Selected item in ListBox - vb.net

Question

I've seen a couple of posts asking a similar question but I have not been able to duplicate the answers in my code successfully.
The following code adds items and their value member to a list box.
Public Shared Sub ListFiles(hTab As Hashtable)
Debug.Print("create file and key" & Now)
Dim Enumerator As IDictionaryEnumerator
Enumerator = hTab.GetEnumerator()
Dim MyKeys As ICollection
Dim Key As Object
MyKeys = hTab.Keys()
If (hTab.Count > 0) Then
For Each Key In MyKeys
Dim sfileName As String = hTab(Key)
Dim first As Integer = sfileName.IndexOf("_")
Dim last As Integer = sfileName.LastIndexOfAny("_")
Dim first2 = (first + 1)
Dim splitFile = sfileName.Substring(first2)
frmViewFiles.ListBox1.Items.Add(splitFile)
frmViewFiles.ListBox1.ValueMember = Key
frmViewFiles.ListBox1.SelectedValue = Key
Next
End If
End Sub
When I run my code to get the selected items value member
Dim file = ListBox1.ValueMember.ToString()
I can acess the first item I choose but subsequent selections dont change the value member to that of the selected item.
Please direct me.
Thank you for your answers. this is my new code:
Public Shared Sub runListFiles(CustomerId As String)
Dim cfp As New CloudFilesProvider(cloudId)
Dim containerObjectList As IEnumerable(Of ContainerObject) = cfp.ListObjects(container:="EstherTest", identity:=cloudId, prefix:=CustomerId & "_")
For Each file As ContainerObject In containerObjectList
Dim sFullFileName As String = file.Name
Dim first As Integer = sFullFileName.IndexOf("_")
Dim first2 = (first + 1)
Dim splitFile = sFullFileName.Substring(first2)
'frmViewFiles.ListBox1.Items.Add(splitFile)
'frmViewFiles.ListBox1.ValueMember = sFullFileName
Dim fb = New myFile
fb.FileName = splitFile
fb.FullPath = sFullFileName
frmViewFiles.ListBox1.Items.Add(fb)
frmViewFiles.ListBox1.DisplayMember = fb.FileName
frmViewFiles.ListBox1.ValueMember = fb.FullPath
This is my class:
Public Class myFile
Public Property FileName As String
Public Property FullPath As String
Public Sub New(f As String, b As String)
FileName = f
FullPath = b
End Sub
End Class
Please see my comment below and assist

Answer 1

ValueMember is supposed to indicate the property name of an object added to the Items collection: the property to use as the actual value for the items in the ListControl.
You are not adding objects to the control, so Key from the hashtable is meaningless as the ValueMember. Your post references a file variable in passing, so I will assume this revolves around showing the filename while wanting to get the full pathname when selected/clicked. WebForms/Winforms/WPF was not indicated, I am assuming WinForms:
Public Class myFile
Public Property FileName As String
Public Property FullPath As String
Public Property FileSize As Int64 ' just so there is something else
Public Sub New(f as String, p as String, s as Int64)
FileName = f
FullPath = b
FileSize = s
End Sub
End Class
Lets say we want to add some of these to a ListBox, for each item added we want FileName to display as the text, but want to get them back by FullPath:
Dim f As myFile
' assume these come from a fileinfo
For Each fi as FileInfo in DirectoryInfo.GetFiles(searchFor)
f = New myFile
f.FileName = fi.Name
f.FullPath = fi.FullPath
f.FileSize = fi.Length
' myFile accepts all the prop values in the constructor
' so creating a new one could also be written as:
' f = New myFile(fi.Name, fi.FullPath, fi.Length)
myListBox.Items.Add(f)
Next n
If the myFile objects were stored to a List(of myFile) rather than adding them to the control, we can bind the List as the DataSource and not have to iterate or copy:
mylistBox.DataSource = myFileList
Either way, Display- and ValueMember refer to the property names we wish to use:
myListBox.DisplayMember = "FileName" ' indicate property name of obj to SHOW
myListBox.ValueMember = "FullPath" ' prop name of object to return
When you select a listbox item, myListBox.SelectedValue would refer to the FullPath of the myFile object clicked on. The SelectedIndex would still refer to the index of the item in the list.
tl;dr
ValueMember and DisplayMember refers to the Property Names of Objects represented in the list.
Note:

Answer 2

I know this is many years later, but still relevant information.
It took me a while to parse what was said above, until I grokked it fully, so I thought it might help if I restated it slightly.
When you select a listbox item,
myListBox.SelectedValue is the contents of the field, myListBox.ValueMember. ValueMember contains the Field Name, SelectedValue contains the contents of the field.
myListBox.SelectedItem is the contents of the field myListBox.DisplayMember. DisplayMember contains the field name and SelectedItem contains the value of the field.
The SelectedIndex refers to the index of the item in the list. To see which item is selected, reference myListBox.SelectedIndex. You can, for example, change the selection to the last item in the list by using myListBox.SelectedIndex = myListBox.Items.Count - 1
If you want to display the values, then
Console.WriteLine("The value of {0} is {1}",myListBoxDisplayMember,myListBox.SelectedItem)
Console.WriteLine("The Value of {0} is {1}",myListBox.ValueMember,myListBox.SelectedValue)