ReportViewer1 LocalReport SubreportProcessing event doesn't fire

Question

from following two posts, 
http://groups-beta.google.com/group/microsoft.public.sqlserver.reportingsvcs/browse_thread/thread/e5be66e6f49f9d86/f0191d9dd6e3b558?q=subreport+in+reportviewer+local+mode&rnum=1&hl=en#f0191d9dd6e3b558

http://groups-beta.google.com/group/microsoft.public.sqlserver.reportingsvcs/browse_thread/thread/4e94a8f347b4426d/3cc4e95a2fd850a6?q=subreport+in+reportviewer+local+mode&rnum=2&hl=en#3cc4e95a2fd850a6

I learned I have to wire SubreportProcessing event to make SubReport local mode to work. But my problem is the event can't be fired.

Me.ReportViewer1.LocalReport.DataSources.Add(New ReportDataSource("DataSet1", ds.Master))
AddHandler ReportViewer1.LocalReport.SubreportProcessing, AddressOf MySubReportProcessing
Me.ReportViewer1.RefreshReport()

Private Sub MySubReportProcessing(ByVal sender As Object, ByVal e As SubreportProcessingEventArgs)
      e.DataSources.Add(New ReportDataSource("DataSet1", Me.ds.Child))
End Sub

My report will show data from master table, but subreport only says error.

am I missing something here?

Answer 1

You can get that error if the RDL for the subreport cannot be found, or if you haven't supplied data for all the datasets expected by the subreport, or if the main report didn't pass a parameter expected by the subreport.

Answer 2

Here's some sample code:

Imports System
Imports System.Data
Imports System.Windows.Forms
Imports Microsoft.Reporting.WinForms

Public Class Demo
    Inherits Form

    Private orderDetailsData As DataTable = Nothing

    Private Function LoadOrdersData() As DataTable
        ' Load data from XML file
        Dim dataSet as DataSet = new DataSet()
        dataSet.ReadXml("OrderData.xml")
        return dataSet.Tables(0)
    End Function

    Private Function LoadOrderDetailsData() As DataTable
        ' Load data from XML file
        Dim dataSet as DataSet = new DataSet()
        dataSet.ReadXml("OrderDetailData.xml")
        return dataSet.Tables(0)
    End Function

    Private Sub DemoSubReportProcessingEventHandler( _
               ByVal sender As Object, ByVal e As SubreportProcessingEventArgs)
        If orderDetailsData Is Nothing Then
            orderDetailsData = LoadOrderDetailsData()
        End If
        e.DataSources.Add(New ReportDataSource("DataSet1_OrderDetails", orderDetailsData))
    End Sub

    Public Sub New
        me.Text = "Report Control Demo"
        me.ClientSize = new System.Drawing.Size(700, 500)

        Dim reportViewer as ReportViewer = new ReportViewer()

        ' Set Processing Mode

        reportViewer.ProcessingMode = ProcessingMode.Local

        ' Set RDL file

        reportViewer.LocalReport.ReportPath = "Orders.rdlc"

        ' Add a handler for SubreportProcessing

        AddHandler reportViewer.LocalReport.SubreportProcessing, _
                  AddressOf DemoSubReportProcessingEventHandler

        ' Supply a DataTable corresponding to each report data source

        reportViewer.LocalReport.DataSources.Add( _
            new ReportDataSource("DataSet1_Orders", LoadOrdersData()))

        ' Add the reportviewer to the form

        reportViewer.Dock = DockStyle.Fill
        me.Controls.Add(reportViewer)

        ' Process and render the report

        reportViewer.RefreshReport()
    End Sub

    Public Shared Sub Main(args as string())
        Application.Run(new Demo())
    End Sub
End Class

Answer 3

Rajeev, Thanks for the replies.

You are right, my subreport had error. It would be nice in the final version we can see some error message when compiling or runtime.

I have another question.

I am doing like your demo code. a little differnent is I fill my dataset first, which include two datatables for all of  the masters and details. Then in subreportprocessing event, I use details datatable.select to filter details by the e.parameter. I design it this way assuming it is much faster than going to database to get detail every time subreportprocessing fires.

But the performance is very bad, it took almost 5+ seconds to run 20+ master rows, 100+ detail rows report. It seems the botteneck is the every datatable.select statement.

What is your suggestion? From the RS BOL, I know performance is better to use data region than subreport. But it should not be that worse, I think I am doing something wrong here.

Wei

Answer 4

One thing you can try is to do the filtering in RDL instead of doing datatable.select. In my sample code I am supplying the same data each time the SubreportProcessing event fires, and then using a filter expression in the subreport RDL. You should still try to avoid subreports if you can, for performance reasons.

Answer 5

Filter in RDL of subreport does help improve performance. But still not good enough, I said it takes 5+ seconds if I use datatable.select, now I think I under estimated it. I would say it takes 10+ seconds if use datatable.select, 5+seconds if use filter in subreport.

So it is a improvement. But still not good enough compared to my Access report. You know I am importing 150+ reports from MS Access.  The same report in access only takes 2- seconds. Something can be done to improve the subreport performance, maybe the engine, maybe RDL of my report. don't know.

Answer 6

Hi all,

 

I was reading this thread (as I struggle to get subreports working) and something in this response confused me.  You wrote that some possible reasons that the subreportProcessing event isn't being triggered could be:

 

You can get that error if the RDL for the subreport cannot be found, or if you haven't supplied data for all the datasets expected by the subreport, or if the main report didn't pass a parameter expected by the subreport.

 

Here's what I don't understand:  Isn't the whole point of the subreportProcessing event firing is that that's the point at which I should take the currently selected values of the parent report parameters in order to fetch the data for all the datasets expected by the subreport?

 

Then again, I still haven't been able to get that event to fire, so I might be way off.

 

Thanks for your time in advance,

Jeremy

Answer 7

hello

I hav the same problem, I need to use a subreport to show  some detail for every row on the main report,  and I got "

• An error occurred during local report processing.
  • Value cannot be null. Parameter name: value

"

I dont know why , my situation is

the sub reoprt is in the same directory than the main report
the subreport request 2 parameters in order to call some bussines object and fill the data, I will do this in the ReportViewer1.LocalReport.SubreportProcessing

The event NEVER raise,.. I guess because the error

do u have some complete example , so I can download to really understand how to work with subreports?

THANKS IN ADVANCE

---

Salu2 Sergio T

Answer 8

C# 2010 SP1, 

Hi there,

I have the same issue.

My Parent report is fine. My Child report1 is fine as well (Has data), but I do not know how to fire           reportViewer1.LocalReport.SubreportProcessing +=  new SubreportProcessingEventHandler(ContactSupplierProcessingEventHandler);

Please help

---

Alex

Answer 9

Never mind i Found it

---

Alex

Answer 10

If you have a ReportViewer.Reset, your AddHandler must follow it.

ReportViewer1.Reset()

AddHandler ReportViewer1.LocalReport.SubreportProcessing, AddressOf LocalReport_SubreportProcessing