I was over-complicating things.  This works just fine. 

Private Sub WebTab1_TabItemAdded(sender As Object, e As Infragistics.Web.UI.LayoutControls.TabItemEventArgs) Handles webTab1.TabItemAdded

e.TabItem.UserControlUrl ="/user_controls/myusercontrol.ascx"

WebTab1.SelectedIndex = WebTab1.Tabs.Count - 1

WebTab1.Tabs(WebTab1.SelectedIndex).FindChildControl("txtPartNumber").Focus()

End Sub

Hello steva,

Please let me know if you need further assistance.

Hello steva,

Thank you for the update and details.

It is also possible that the event at which the textbox is being accessed is too early. I may need more information regarding the UserControl and the events at which the WebTab is created as well.

If you have any questions, please let me know as well.

It must have something to do with dynamically creating the user control and viewstate.  Viewstate is enabled for all controls.  Any suggestions?

I am now able to find the control, but the text returned from the found control is an empty string although the tab and the textboxes on it seem to be displaying correctly. Here is the code for adding the tab to the WebTab

Dim newTab As New Infragistics.Web.UI.LayoutControls.ContentTabItem

Dim newControl As WUC_CCDetail = DirectCast(LoadControl("MyUserControl.ascx"),MyUserControl)

newTab.UserControlUrl = "MyUserControl.ascx"

newControl.Part = dRow!PartNumber.ToString      (this is a public property on the user control that sets the txtPartNumber textbox text)

newTab.Text = dRow!PartNumber.ToString.Trim

newTab.Controls.Add(newControl)

WebTab1.Tabs.Add(newTab)

This seems to be working.  The tab is added and the part Number textbox is filled in.

This is what I'm doing to try to get the text of the part number textbox:

Dim tempPart As String

Dim octl As Control = WebTab1.Tabs(0).FindChildControl("txtPartNumber")

If octl IsNot Nothing Then

tempPart = CType(octl, TextBox).Text

End If

It finds the txtPartNumber control but the text in it is an empty string.