Disabling checkbox selections in VB .NET 2008 Winform Listview - vb.net

Question

How do you disable additional checkbox selections/deselections without sacrificing the functionality of the ListView? I know you can call: ListView.Enabled = False, but that also disables any scrolling within it.
For example: I have a timer that starts a backup based on the Listview items that are checked. After a certain time, I don't want the end-user to be able to click on any of the checkboxes within the listview (so I have a set number of items to backup), but I do want them to be able to scroll the list while the backup is being performed. I tried this:
Private Sub clboxOptions_ItemChecked(ByVal sender As System.Object, ByVal e As System.Windows.Forms.ItemCheckedEventArgs) Handles clboxOptions.ItemChecked
If backupStarted = True Then
If e.Item.Checked = True Then
e.Item.Checked = False
Else
e.Item.Checked = True
End If
But this doesn't seem to work for me.
Thanks!
JFV

Answer 1

Here is an other method to disable the users click on listviewitem checkbox.
Public Sub ChangeItemCheckState(ByVal val As Boolean, ByVal index As Integer)
If Monitor.TryEnter(Me.Items(index), 10) Then
Try
Me.Items(index).Checked = val
Finally
Monitor.Exit(Me.Items(index))
End Try
End If
End Sub
Public Sub ChangeItemCheckState(ByVal val As Boolean, ByVal item As ListViewItem)
If Monitor.TryEnter(item, 10) Then
Try
item.Checked = val
Finally
Monitor.Exit(item)
End Try
End If
End Sub
Private Sub ListviewOPC_ItemCheck(sender As Object, e As ItemCheckEventArgs) Handles Me.ItemCheck
If Monitor.IsEntered(Me.Items(e.Index)) Then
'
Else
'prevent click from users
e.NewValue = e.CurrentValue
End If
End Sub
this method is thread safe. To change the checkedstate of an item you have to call the ChangeItemCheckState methods. If you want to enable/disable the itemcheck by click, you have to add another property.
Private disableUserCheckItem As Boolean
Public Property PreventUserCheckItem() As Boolean
Get
Return disableUserCheckItem
End Get
Set(ByVal value As Boolean)
disableUserCheckItem = value
End Set
End Property
Public Sub ChangeItemCheckState(ByVal val As Boolean, ByVal index As Integer)
If Monitor.TryEnter(Me.Items(index), 10) Then
Try
Me.Items(index).Checked = val
Finally
Monitor.Exit(Me.Items(index))
End Try
End If
End Sub
Public Sub ChangeItemCheckState(ByVal val As Boolean, ByVal item As ListViewItem)
If Monitor.TryEnter(item, 10) Then
Try
item.Checked = val
Finally
Monitor.Exit(item)
End Try
End If
End Sub
Private Sub ListviewOPC_ItemCheck(sender As Object, e As ItemCheckEventArgs) Handles Me.ItemCheck
If Monitor.IsEntered(Me.Items(e.Index)) Then
'do nothing or other nessesary things.
Else
'prevent click from users
If PreventUserCheckItem Then
e.NewValue = e.CurrentValue
End If
End If
End Sub

Answer 2

Instead using the built-in CheckBoxes property, you could draw the check boxes yourself.
Google around and find an example of an OwnerDraw ListView. Draw the checkboxes yourself. Add a new property to your ListView (something like ReadOnly). When ReadOnly is true, draw the checkboxes as disabled and ignore the click messages.

Answer 3

You could use ObjectListView (which is a wrapper around a normal .NET ListView). It provides a callback, CheckStatePutter, which is called when the user clicks on a checkbox. In that callback, you can decide whether or not to accept the new checkbox value.
This is a recipe describing this process: How do I use checkboxes in my ObjectListView?

Answer 4

I found out what my issue was. I was using the 'ItemChecked' instead of the 'ItemCheck' Method. The below code works for me:
Private Sub clboxOptions_ItemCheck(ByVal sender As System.Object, ByVal e As System.Windows.Forms.ItemCheckEventArgs) Handles clboxOptions.ItemCheck
Try
If backupStarted = True Then
If e.CurrentValue <> e.NewValue Then
e.NewValue = e.CurrentValue
Else
e.NewValue = e.NewValue
End If
End If
End Sub

Answer 5

I want disable CheckBox in Listview. When I click Button Go. I was using the 'ItemChecked' Method. I use code this:
Public Sub CheckBoxChecked(ByVal sender As Object, ByVal e As System.Windows.Forms.ItemCheckedEventArgs)
Try
If bCheckFromEvent Then
bCheckFromEvent = False
Return
End If
If BrunService Then
bCheckFromEvent = True
ListView.Items(e.Item.Index).Checked = Not ListView.Items(e.Item.Index).Checked
End If
Catch ex As Exception
MsgBox("CheckBoxChecked: " & ex.Message, MsgBoxStyle.Critical Or MsgBoxStyle.OkOnly, "ERROR")
End Try
End Sub