Tabpage - Add or insert tabpage with order determined

[Smartacus]

I have a main page (VB.Net 2012 4.0) which I have a treeview on the left that opens forms into a tab control page on the right. This all works fine except I would like to be able to determine the tab page display order when the treeview link is clicked. My example would be:

Treview Item

1: Demographics
2: Intake
3: Assessment(1)
4: Assessment(2)
5: Special Needs
6: Outcome

When the main form is opened, one tab page is created with a user control added as a facesheet that basically summarizes the users open tasks, the index is 0. After selecting the client filter they can then select a treeview item at random e.g. Item 4, Item 6, Item, Item 5, Item 1 and so on.

My goal is to place the new tab page in the order which they should be read as 1,2,3,4,5 as it is being added so tab 5 would always be to the left of tab 6 etc.

I have looked at dozens of examples and tried Insert instead of Add and giving the new tab page an pre-determined index but you can not add a tab with index 3 if it is greater than the collection.

Help needed.

Thanks.

[dday9]

The way that I would do it is to set the Tag property of the tab page to whatever order it should be in. Then whenever you add a page, use the Add method, then iterate through each tab to check which order they should be in, and finally set the proper order then.

[jmcilhinney]

The way that I would do it is to set the Tag property of the tab page to whatever order it should be in. Then whenever you add a page, use the Add method, then iterate through each tab to check which order they should be in, and finally set the proper order then.

I like the idea of using the Tag but don't Add and then re-order. Determine the correct order first and then use Insert. E.g.

'Get the first TabPage with a greater Tag value than the one being inserted.
Dim followingTab = myTabControl.TabPages.Cast(Of TabPage)().FirstOrDefault(Function(tp) CInt(tp.Tag) > CInt(tabToInsert.Tag))
 
If followingTab Is Nothing Then
    'There is no following tab so add this one to the end.
    myTabControl.TabPages.Add(tabToInsert)
Else
    'Insert this tab before the following one.
    myTabControl.TabPages.Insert(myTabControl.TabPages.IndexOf(followingTab), tabToInsert)
End If

[Smartacus]

Function(tp) CInt(tp.Tag) > CInt(tabToInsert.Tag)

Do I need to enter the tag property as a string "1"?

[dday9]

Yes, and then CInt converts it back to an Integer.

Edit - I wasn't thinking. You could do it like that, or you could set it to just the number 1 as a Tag is of type Object. Either way would work, but just simply setting it to 1 is sufficient enough and a little less error prone.

[jmcilhinney]

Function(tp) CInt(tp.Tag) > CInt(tabToInsert.Tag)

Do I need to enter the tag property as a string "1"?

If you set a Tag property in the designer then it will be set to a String. If you set it in code then it will hold whatever type you assign. Either way though, you'll have to cast/convert to type Integer at run time when you use it, because Tag is type Object, so you'll be using CInt either way.

[Smartacus]

I do not have something right here.

I am getting the behavior I expected with create a tabpage and adding form to it, and even my function to check for existing tabpage is working and not adding another tabpage if one by the same name already exists, but still not in order of TAG

'function Call
ShowTabForm(frmIntake, "Intake")

 'Function to show a form in tabcontrol.
    Public Function ShowTabForm(ByVal FormName As Form, ByVal strTitle As String) As Boolean

        Dim rVal As Boolean = False
        Dim frm As New Form
        frm = FormName
        Dim tpp As New TabPage
        tpp.Tag = frm.Tag
        tpp.Name = frm.Name

        Dim strTabName As String = tpp.Name
        tpp.Text = strTitle

        If Not IsTabOpen(tpp.Name) Then
            'Get the first TabPage with a greater Tag value than the one being inserted.
            Dim followingTab = tbCtrl.TabPages.Cast(Of TabPage)().FirstOrDefault(Function(tp) CInt(tp.Tag) > CInt(frm.Tag))
            If followingTab Is Nothing Then

                'There is no following tab so add this one to the end.

                tbCtrl.TabPages.Add(tpp)
                frm.TopLevel = False
                frm.FormBorderStyle = System.Windows.Forms.FormBorderStyle.None
                Me.tbCtrl.TabPages(tbCtrl.TabPages.IndexOf(tpp)).Controls.Add(frm)

                Me.tbCtrl.SelectTab(tpp.Name)
                frm.Show()
            Else
                'Insert this tab before the following one.
                tbCtrl.TabPages.Insert(tbCtrl.TabPages.IndexOf(followingTab), tpp.Tag)
            End If
        Else
            Me.tbCtrl.SelectTab(tpp.Name)
        End If
        Return rVal
    End Function
    'Determine if a formtab is already open.
    Public Function IsTabOpen(ByVal tabname As String) As Boolean
        Dim rVal As Boolean = False
        Dim tp As TabPage
        For Each tp In Me.tbCtrl.TabPages
            If tp.Name = tabname Then
                rVal = True
                Exit For
            End If
        Next
        Return rVal
    End Function

[Smartacus]

I am assuming that this is where I am getting it wrong. But I have switched things around and still not inserting before other tabs if tag value is less than the ones on right.

 'Insert this tab before the following one.
                tbCtrl.TabPages.Insert(tbCtrl.TabPages.IndexOf(followingTab), tpp.Tag)

[Smartacus]

I have checked my tags and they are numbered starting at 0, I removed the first default tab so the menu click now creates the first tab index. Still not loading in order I want. HELP!!