The ConnectionString not initialized - asp.net

Question

Good day All
i have an issue with connection string
I'm getting this exception
The ConnectionString property has not been initialized.
on the RowDataBound of the outer gridview sub routine (VB.NET)
when trying to bind data to inner gridview
the code:
Private Function ChildDataSource(ByVal strCustometId As String, ByVal strSort As String) As SqlDataSource
Dim strQRY As String = ""
Dim connString As String = ConfigurationManager.ConnectionStrings("SiteConnectionString").ConnectionString
Using conn As New SqlConnection(connString)
conn.Open()
strQRY = "SELECT [Sortie].[OdvID],[Sortie].[SortieID]," & "[Sortie].[Fuel],[Sortie].[Captain],[Sortie].[Crew] FROM [Sortie]" & " WHERE [Sortie].[OdvID] = '" & strCustometId & "'" & "UNION ALL " & "SELECT '" & strCustometId & "','','','','' FROM [Sortie] WHERE [Sortie].[OdvID] = '" & strCustometId & "'" & "HAVING COUNT(*)=0 " & strSort
'Initialize command object
Dim cmd As New SqlCommand(strQRY, conn)
Dim dsTemp As New SqlDataSource()
dsTemp.SelectCommand = strQRY
Return dsTemp
End Using
End Function
This event occurs for each row
Protected Sub gvOdv_RowDataBound(ByVal sender As Object, ByVal e As GridViewRowEventArgs)
Dim connString As String = ConfigurationManager.ConnectionStrings("MoyensAeriensConnectionString").ConnectionString
Dim conn As New SqlConnection(connString)
conn.Open()
Dim row As GridViewRow = e.Row
Dim strSort As String = String.Empty
' Make sure we aren't in header/footer rows
If row.DataItem Is Nothing Then
Return
End If
'Find Child GridView control
Dim gv As New GridView()
gv = DirectCast(row.FindControl("gvSorties"), GridView)
'Check if any additional conditions (Paging, Sorting, Editing, etc) to be applied on child GridView
If gv.UniqueID = gvUniqueID Then
gv.PageIndex = gvNewPageIndex
gv.EditIndex = gvEditIndex
'Check if Sorting used
If gvSortExpr <> String.Empty Then
GetSortDirection()
strSort = " ORDER BY " & String.Format("{0} {1}", gvSortExpr, gvSortDir)
End If
'Expand the Child grid
ClientScript.RegisterStartupScript([GetType](), "Expand", "<SCRIPT LANGUAGE='javascript'>expandcollapse('div" & DirectCast(e.Row.DataItem, DataRowView)("OdvID").ToString() & "','one');</script>")
End If
'Prepare the query for Child GridView by passing the Odv ID of the parent row
gv.DataSource = ChildDataSource(DirectCast(e.Row.DataItem, DataRowView)("OdvID").ToString(), strSort)
gv.DataBind()
'Add delete confirmation message for Customer
Dim l As LinkButton = DirectCast(e.Row.FindControl("linkDeleteCust"), LinkButton)
l.Attributes.Add("onclick", "javascript:return " & "confirm('Are you sure you want to delete this Customer " & DataBinder.Eval(e.Row.DataItem, "OdvID") & "')")
End Sub
thanks (I'v been hunting this error for last 3 hours)

Answer 1

It looks like both code snippets use a separate connection string. ChildDataSource uses "SiteConnectionString" and gvOdv_RowDataBound uses "MoyensAeriensConnectionString", hopefully I'm not pointing out the obvious here, but if so, are both of those present in your config file?

Answer 2

When you have created the SqlDataSource dynamically in your first code snippet, You haven't set its ConnectionString property, that's why this error is coming up.
Note that you also haven't assigned any ID to your SqlDataSource. Its better to do this too.
You also need to set the ConnectionString property of SqlDataSource.
Dim dsTemp As New SqlDataSource()
dsTemp.ID = "mySqlSourceControl"
dsTemp.ConnectionString = ConfigurationManager.ConnectionStrings("ConnectionStr").ConnectionString
dsTemp.SelectCommand = strQRY
...
Rest of things should also be fine like: web.config has a connection string for the key mentioned [ e.g. ConnectionStr here]

Answer 3

Instead of returning a SQLDataSource as the gridview's datasource, perhaps return a dataset.
Private Function ChildDataSource(ByVal strCustometId As String, ByVal strSort As String) As DataSet
Dim strQRY As String = "SELECT [Sortie].[OdvID],[Sortie].[SortieID]," & "[Sortie].[Fuel],[Sortie].[Captain],[Sortie].[Crew] FROM [Sortie]" & " WHERE [Sortie].[OdvID] = '" & strCustometId & "'" & "UNION ALL " & "SELECT '" & strCustometId & "','','','','' FROM [Sortie] WHERE [Sortie].[OdvID] = '" & strCustometId & "'" & "HAVING COUNT(*)=0 " & strSort
Dim connString As String = ConfigurationManager.ConnectionStrings("SiteConnectionString").ConnectionString
Using conn As New SqlConnection(connString)
conn.Open()
Using da As New SqlDataAdapter(strQRY, conn)
Using ds As New DataSet
If da.Fill(ds) > 0 Then
Return ds
Else
Return New DataSet
End If
End Using
End Using
End Using
End Function
The method to set the datasource of the child gridview remains the same.