Microsoft Reporting with Collection as DataSource

Question

Hi !

I'm working with MS Reporting Services. The underlying datasource is

IEnumerable<MyObject>, I'm not using DataSets.

Every MyObject has properties and some other IEnumerable collections. In the report I want to display all the properties from MyObject and the collections lists too. I didn't know how to display this inner collections, so I've made a SubReport to which I passed the MyObject.Id so that the SubReport could retrieve the object by himself and Build a the DataSource for these inner collections. I do this in this event.

myReportViewer.LocalReport.SubreportProcessing += new SubreportProcessingEventHandler(LocalReport_SubreportProcessing);

private void LocalReport_SubreportProcessing(object sender, SubreportProcessingEventArgs e)
{
    int id;
    if (e.Parameters.Count > 0 && int.TryParse(e.Parameters[0].Values[0], out id))
    {
     MyObject current = myObjects.Where(x => x.MyObject.Id == id).FirstOrDefault();

     InnerListBindingSource.DataSource = current.InnerCollection;
     e.DataSources.Add(new Microsoft.Reporting.WinForms.ReportDataSource(
      "MyInnerCollectionDataSource", InnerListBindingSource));
    }
}

But there is always "The SubReport could not be shown" in my Master Report. (Master report - subreport are correctly binded)

Any Idea why? Or how to resolve this in a more elegant way ?

Thank you

Answer 1

If I understand you correctly, you have a structure that resembles a table. So why don't you take a DataTable? ReportingServices offers easy access to those. Or did I get you wrong there?

Answer 2

OK.

So I went to this solution and it's working:

private IEnumerable<MyObject> myObjects;

public ReportViewerForm(IEnumerable<MyObject> myObjects)
{
    InitializeComponent();

    this.myObjects = myObjects;
    this.WindowState = FormWindowState.Maximized;

    ReportViewer reportViewer = new ReportViewer();            

    reportViewer.ProcessingMode = ProcessingMode.Local;

    reportViewer.LocalReport.ReportEmbeddedResource = @"SomePath." + "Report1.rdlc";
    /*reportViewer.LocalReport.ReportPath = @"SomePath\Report1.rdlc"; */

    reportViewer.LocalReport.SubreportProcessing +=
       new SubreportProcessingEventHandler(SubreportProcessingEventHandler);            

    reportViewer.LocalReport.DataSources.Add(
       new ReportDataSource("MyDataSource", myObjects));

    reportViewer.LocalReport.SetParameters(new List<ReportParameter> 
    {
     new ReportParameter("param1", ..WhatEver..),
     ...
    }); 

    reportViewer.Dock = DockStyle.Fill;
    this.panel1.Controls.Add(reportViewer);

    reportViewer.RefreshReport();
}

void SubreportProcessingEventHandler(object sender, SubreportProcessingEventArgs e)
{          
    /* For example ID parsing.. when you have it defined in .rdlc file.. */
    int id;
    if (e.Parameters.Count > 0 && int.TryParse(e.Parameters[0].Values[0], out id))
    { 
     MyObject current = myObjects.Where(x => x.MyObject.Id == id).FirstOrDefault();

     e.DataSources.Add(new Microsoft.Reporting.WinForms.ReportDataSource(
      "InnerListDataSource", current.InnerList));              
    }           
}