Question

The application that I am working on is a Service Desk App. I have a form there that uses a DropDownList that contains employees names coming from the Active Directory. Any employee can make a request and save it.

Problem arises when an employee leaves the company and consequently his account is deleted from the Active Directory. When some other employee searches the DB to finds a relevant Service Ticket that could be of his use, when tries to open it an error is thrown that indicates that the name does not exist in the DropDownList items.

What I need is a solution so that the functionality will remain the same (be able to delete the Active Directory entry), but no error will be thrown.

I am using as indicated by the tags, ASP.NET with VB. Solutions with C# are also welcome.

Thank you in advance for your suggestions to my problem.

UPDATE:

I am adding some code so that it can be more clear.

ASPX: (This is huge, I am putting only the DropDownList in question)

<asp:FormView ID="FormView1" runat="server" DataSourceID="SqlDataSource1" 
        DataKeyNames="ITRequestId">
        <EditItemTemplate>
            <br />
            <asp:LinkButton ID="LinkButton5" runat="server" CausesValidation="True" 
                CommandName="Update" Text="Update" CssClass="InsertLink" />
            &nbsp;&nbsp;&nbsp;<asp:LinkButton ID="LinkButton6" runat="server" 
                CausesValidation="False" CommandName="Cancel" Text="Cancel" CssClass="CancelLink" />

                    ........    

                    <div id="user" style="float: left;">
                        <label>User:<asp:RequiredFieldValidator ID="RequiredFieldValidator9" runat="server" ErrorMessage="User" Display="Dynamic" ControlToValidate="DropDownList5" Text="*" ForeColor="#FF0000"></asp:RequiredFieldValidator></label><br />
                        <asp:DropDownList ID="DropDownList5" runat="server" SelectedValue='<%# Bind("ITRequestUserName") %>'>
                            <asp:ListItem Value=""></asp:ListItem>
                            <asp:ListItem Value="All">All</asp:ListItem>
                            <asp:ListItem Value="NA">N/A</asp:ListItem>
                        </asp:DropDownList>
                    </div>

                    .........
        </EditItemTemplate>

CODE BEHIND vb: (This is huge, but I am putting the pageload event where the error is thrown)

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
    If (Not IsPostBack) Then
        If Request.UrlReferrer IsNot Nothing Then
            ViewState("RefUrl") = Request.UrlReferrer.ToString()
        End If
    End If
    'Handles the mode of the FormView according to the request
    If Request.QueryString.Get("ITRequestId") IsNot Nothing Then
        FormView1.DefaultMode = FormViewMode.ReadOnly
        Dim tName As String = DirectCast(FormView1.Row.FindControl("DropDownList5"), DropDownList).SelectedValue
        Dim temptype As String = DirectCast(FormView1.Row.FindControl("DropDownList1"), DropDownList).SelectedItem.Text
        Dim myAD As New tActiveDirectory(LDAPpath)
        Dim lName As String = HttpContext.Current.User.Identity.Name.ToString()
        Dim sDisplayName As String = myAD.GetUserInfo(lName, "displayName")
        Dim cName As String = DirectCast(FormView1.Row.FindControl("Label5"), Label).Text
        If Not (User.IsInRole("Developers") Or User.IsInRole("Administrators") Or tName = sDisplayName Or cName = sDisplayName) Then
            If (temptype = "Access rights") Then
                Response.Redirect("../IT/ITAccessDenied.aspx")
            End If
        End If
        If Not (User.IsInRole("Developers") Or User.IsInRole("Administrators") Or cName = sDisplayName) Then
            If (temptype = "Account") Then
                Response.Redirect("../IT/ITAccessDenied.aspx")
            End If
        End If
        If Not (User.IsInRole("LocalIT")) Then
            If (temptype = "Internal IT Task") Then
                Response.Redirect("../IT/ITAccessDenied.aspx")
            End If
        End If
    Else
        FormView1.DefaultMode = FormViewMode.Insert
        Dim tempstatus As DropDownList = DirectCast(FormView1.Row.FindControl("DropDownList2"), DropDownList)
        tempstatus.SelectedIndex = 3
    End If
End Sub

The error is thrown at Line 11 of the code when declaring the tName variable. And this is happening because the UserName that is in the database and is to be bounded by the DropDownList has been deleted from the ActiveDirectory and thus it does not exist in the values of the List.

Here is the code that populates the DropDownList:

Protected Sub FormView1_ItemCreated(ByVal sender As Object, ByVal e As System.EventArgs) Handles FormView1.ItemCreated
    Dim d1 As DropDownList
    Dim d2 As DropDownList
    Dim myAD As New tActiveDirectory(LDAPpath)
    Dim users As New ArrayList()
    users = myAD.GetAllUsersInfo()
    d1 = DirectCast(FormView1.Row.FindControl("DropDownList5"), DropDownList)
    d2 = DirectCast(FormView1.Row.FindControl("DropDownList7"), DropDownList)
    d1.DataSource = users
    d2.DataSource = users
End Sub

Public Function GetAllUsersInfo() As ArrayList
        Dim Users As New ArrayList()
        Dim myDirectory As New DirectoryEntry(sPath)
        Dim mySearcher As New DirectorySearcher(myDirectory)
        Dim fullName As String
        mySearcher.Filter = "(&(objectCategory=person)(objectClass=user))"
        mySearcher.PropertiesToLoad.Add("sn")
        mySearcher.PropertiesToLoad.Add("displayName")
        mySearcher.Sort.PropertyName = "sn"
        mySearcher.Sort.Direction = SortDirection.Ascending
        Users.Add("")
        Users.Add("N/A")
        Users.Add("All")
        For Each result As DirectoryServices.SearchResult In mySearcher.FindAll
            fullName = result.Properties("displayName")(0).ToString
            Users.Add(fullName)
        Next
        Return Users
    End Function

Any help with this will be appreciated. Thank you.

Answer 1

Your question does not have much detail regarding code. But it sounds like your app is trying to select a value in the DDL that is not there (anymore). Just check before selecting like this:

Dim ddl As DropDownList
Dim item As ListItem = ddl.Items.FindByValue("Kostopoulos")
If item IsNot Nothing Then
  ddl.SelectedIndex = ddl.Items.IndexOf(item)
Else
  ddl.Items.Add(New ListItem("Not available"))
  ddl.Enabled = False
End If