asp.net UpdatePanel with UserControls and Page Level Async Method

问题

I have an asp.net page which has amoungst some basic labels etc, and an updatepanel containing a dynamic list of UserControls. Each control has its own UpdatePanel, and basic controls. I have hatched together a collaps/expand feature for these controls and has been working fine to date.

To make the page more efficient I have been working to 'Async-ify' the heavy data processing that happens during load, to display in these fields and user controls.

After all of these changes everything still works fine (including a massive performance boost), except one thing - the collapse/expand no longer works. The limited data viewable in collapsed mode' has updated fine.

Reverting back to a non async call for the data, and everything works fine again, but slow again.

It is like they are constantly forced back to their original default state (collapsed), on each postback, triggered by the collapse/expand button. But nothing has changed from this perspective. I have literally only changed the data call to await async instead of non-async, which as i overstate, is fine for everything except this issue.

I can post any code, but not sure what is relevant. The only change I have made is as follows:

Protected Async Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
   Update()
End Sub

Private Async Function Update() As Task

    Dim AController As New CIP_WS.ARFController

    ARF = AController.GetARFWithResults(Client.ClientID, PRN, Nothing, StartTime, EndTime, CIP_WS.LabResultController.InequalityModes.AsIs)

    PrintBasic()

    PrintSPC()

    PrintPhotos()

    PrintResults()

    PrintHistoricEdits()

End Function

Above works fine - non async

Protected Async Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
   RegisterAsyncTask(New PageAsyncTask(Function() Update()))
End Sub

Private Async Function Update() As Task

    Dim AController As New CIP_WS.ARFController

    Dim ARFTask As Task(Of CIP_WS.ARF) = AController.GetARFWithResultsAsync(Client.ClientID, PRN, Nothing, StartTime, EndTime, CIP_WS.LabResultController.InequalityModes.AsIs)

    ARF = Await ARFTask

    PrintBasic()

    PrintSPC()

    PrintPhotos()

    PrintResults()

    PrintHistoricEdits()

End Function

Above, everything works fine, except usercontrol's not persisting their updated collapsed/expanded state.

Any help most appreciated

EDIT _____

Expand/Collaps method, as requested:

Partial Class wucLabResultPack

Inherits System.Web.UI.UserControl
Private _Expanded As Boolean

 Public Property Expanded() As Boolean
    Get
        Return _Expanded
    End Get
    Set(ByVal value As Boolean)
        _Expanded = value
        ViewState("Expanded") = _Expanded
        UpdateExpandPanel()
    End Set
End Property

Protected Sub imgExpand_Click(ByVal sender As Object, ByVal e As System.Web.UI.ImageClickEventArgs) Handles imgExpand.Click
    ToggleExpanded()
End Sub

Private Sub ToggleExpanded()
    Expanded = Not Expanded
End Sub

Private Sub UpdateExpandPanel()
    If Expanded Then
        pnlDetail.Visible = True
        imgExpand.ImageUrl = "Images/Shrink.png"
    Else
        pnlDetail.Visible = False
        imgExpand.ImageUrl = "Images/Expand.png"
    End If
End Sub

 Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
    If IsPostBack Then
        Expanded = CInt(ViewState("Expanded"))
    End If
End Sub

来源：https://stackoverflow.com/questions/44285371/asp-net-updatepanel-with-usercontrols-and-page-level-async-method

标签

ASP.NET

vb.net

asynchronous

user-controls

updatepanel