Chapter 30 questions and Issues

Arkay_Mann · #1 (**permalink**) September 24th, 2010, 07:47 PM

I want to create a basic "this works and I can modify it once I get it working"
report. As it followed the chapter I ran into some problems.

Basically 2 things

1. In Generating the Report the is no mention of the fact that if creating a report by hand or adding it to an existing project this using needs to be added.

Code:

using Microsoft.Reporting.WinForms;

Also from searching the net it looks like the Report1.rdlc should have a BuildAction property set to "Embedded Resource"

2. I am using C# chose to embed the report. I added the 4 example lines from this section

Code:

LocalReport reportEngine = reportViewer1.LocalReport;
reportEngine.ReportEmbeddedResource = "Test4.Report1.rdlc";
reportEngine.DataSources.Add(new ReportDataSource("CustomerData",data));
reportViewer1.RefreshReport();

When creating the report the namespace was "Test4"
and I accepted all the default names as I followed the chapter.

I did create my own xsd file "APM.xsd" that has a datatable object named "apmast01" and a TableAdapter object named "apmast01TableAdapter". The TableAdapter is based on a SelectCommand. I do not want to use the Entity Framework at this point

It no problem with lines 1, 2 and 4
But I do NOT understand what is supposed to be used in line 3.
Obviously it is not "CustomerData" and data but what should it be?

christhecoder · #2 (**permalink**) January 21st, 2011, 11:35 AM

Hi Arkay

When instantiating a ReportDataSource object (as per this line):

Code:

reportEngine.DataSources.Add(new ReportDataSource("CustomerData",data));

You are passing it the name of the data source that you created in the report ("CustomerData") (as per the section titled Defining Data Sources), and then the collection of objects that you wish to pass to your report and populate it with (data). This collection must have previously been populated in your code. I stated that my example was populating the "data" collection variable with data from the Entity Framework, but this can be from any source (such as your XML file) and of any format - as long as it is a collection.

Hope this helps...

Chris

fbuxo · #3 (**permalink**) April 27th, 2012, 06:57 AM

Chris, can you show an example of a VB code to create the data collection variable that populates such data from an Entity Framework? Thanks.

christhecoder · #4 (**permalink**) April 27th, 2012, 07:35 AM

For example:

Code:

Dim qry = From co In context.SalesOrderHeaders
          Where co.CustomerID = customerID AndAlso co.OrderDate > fromDate
          Select co

e.DataSources.Add(New ReportDataSource("OrderData", qry))

fbuxo · #5 (**permalink**) April 27th, 2012, 10:34 AM

Thank you for your quick response. I get this error. Please advise, thanks.
"An error has occurred during report processing.
The ObjectContext instance has been disposed and can no longer be used for operations that require a connection."

Code:

 Protected Sub Page_Load(sender As Object, e As System.EventArgs) Handles Me.Load
        Dim reportEngine As LocalReport = ReportViewer1.LocalReport
        reportEngine.ReportPath = "ReportMaster.rdlc"
        Using Context As New teconcrete_TEdbModel.teconcrete_TEdbEntities()
            Dim qry = From co In Context.Tests
            Select co
            reportEngine.DataSources.Add(New ReportDataSource("DataSet1", qry))
        End Using

    End Sub

fbuxo · #6 (**permalink**) April 27th, 2012, 10:37 AM

An error has occurred during report processing.
The ObjectContext instance has been disposed and can no longer be used for operations that require a connection.

christhecoder · #7 (**permalink**) April 28th, 2012, 10:24 PM

LINQ queries have a delayed execution, and you're disposing of the object context before the query is being executed (by wrapping it in a Using block). You can force it to execute immediately by adding a ToList() or ToArray() to the end of the query. For example:

reportEngine.DataSources.Add(New ReportDataSource("DataSet1", qry.ToArray()))

fbuxo · #8 (**permalink**) April 29th, 2012, 07:42 AM

The report remains loading without showing data, in a permanent loop. Do I have to add something to my code something as "If Not Is postback"?. How that code would look like?
My report is based on an entity dataset that calls a select query stored procedure function, TEdbEntitites(GetTests). Does that change the way the query should be written? As for example

Code:

Dim qry = myEntities.GetTests()

. Please advise, thank you very much for your help.

Code looks like this:

Code:

Dim reportEngine As LocalReport = ReportViewer1.LocalReport
reportEngine.ReportPath = "ReportMaster.rdlc"
Using myEntities As New TEdbModel.TEdbEntities()
            Dim qry = From test In myEntities.Tests
            Select test
            ReportViewer1.LocalReport.DataSources.Add(New ReportDataSource("DataSetT", qry.ToList()))
        End Using

christhecoder · #9 (**permalink**) April 29th, 2012, 09:03 AM

I don't know why you'd be getting in a loop. Have you tried stepping through the code to see why it's getting stuck. You can try sending me your project to christhecoder AT gmail and I can take a look. However, I'm on quite a tight schedule at the moment, so I can't guarantee I'll be able to look at it immediately.

fbuxo · #10 (**permalink**) April 29th, 2012, 10:22 AM

I was able to stop the infinite looping and now the master report is loading perfect. Nevertheless, the subreport won't show. Please advise. Thank you very much!!
Here is the complete code:

Code:

Imports System
Imports System.Data
Imports System.Configuration
Imports System.Web
Imports System.Web.Security
Imports System.Web.UI
Imports System.Web.UI.WebControls
Imports System.Web.UI.WebControls.WebParts
Imports System.Web.UI.HtmlControls
Imports Microsoft.Reporting.WebForms
Imports TEdbModel



Partial Class Reports_ReportWeb
    Inherits System.Web.UI.Page
   
    Protected Sub Page_Load(sender As Object, e As System.EventArgs) Handles Me.Load
        AddHandler ReportViewer1.LocalReport.SubreportProcessing, AddressOf ProcessSubreport
        If Not IsPostBack Then
            Dim reportEngine As LocalReport = ReportViewer1.LocalReport
            reportEngine.ReportPath = "ReportMaster.rdlc"
            Using myEntities As New TEdbModel.TEdbEntities()
                Dim qry = From r In myEntities.Tests
                Select r
                ReportViewer1.LocalReport.DataSources.Add(New ReportDataSource("DataSetT", qry.ToArray()))
            End Using
            Validate()
        End If

    End Sub

    Private Sub ProcessSubreport(ByVal sender As System.Object, ByVal e As SubreportProcessingEventArgs)


        Dim cylinderid As Integer = Convert.ToInt32(e.Parameters("CylinderID").Values(0))
        Using Context As New TEdbModel.TEdbEntities()

            Dim qry = From r In Context.Cylinders
            Where (r.CylinderID = cylinderid)
                    Select r
            e.DataSources.Add(New ReportDataSource("DatasetC", qry.ToArray()))
        End Using
    End Sub


End Class

Need to download code?

Navigation