RenderBegin killing DrillThrough parameters?

[Jonathan]

I am hosting a Silverlight ReportViewer in a XAML file that programmatically sends parameters to the ReportViewer like this:

void TheReportViewer_RenderBegin(object sender, Telerik.ReportViewer.Silverlight.RenderBeginEventArgs args)
{
    args.ParameterValues["SubjectId"] = subjectId;
    runOnce = true;
}

I also have a DrillThrough action setup on the DetailsSecion of my initial report, which I created through the Design view, so that each details ReportItem has an action that operates like this (taken from the Designer.cs):

navigateToReportAction1.Parameters.Add(new Telerik.Reporting.Parameter("SubjectId", "=Fields.SubjectId"));
navigateToReportAction1.ReportDocumentType = "Application.Reports.ReportType.DetailReport, Application.Reports, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null";

The DrillThrough is intended to load a DetailReport, passing the SubjectId of the particular item clicked in as a parameter. The navigateToReportAction behaves as expected, but my DetailReport loads with the following error.

One or more parameters are not set or have invalid values.

I believe the RenderBegin event might be blowing out my parameters, but even if I try some trickery like this:

private bool runOnce = false;
void TheReportViewer_RenderBegin(object sender, Telerik.ReportViewer.Silverlight.RenderBeginEventArgs args)
        {
            if (!runOnce)
            {
                args.ParameterValues["SubjectId"] = subjectId;
                runOnce = true;
            }
        }

my DetailReport still reaches the ItemDataBound event of the DetailSection with ReportParameters["SubjectId"].Value equaling null.

What am I to do? Has anyone run across a scenario where parameters passed from a DrillThrough don't load in the report navigated to?

Many thanks for your time,
-Jonathan

[Elian]

Hello Jonathan,

To see what values the parameters have, you should use the processing items:

//this will give you the default value you set at design time, not the actual value that is passed
ReportParameters["SubjectId"].Value

//To get the actual values you have to use the processing object
//this is an example showing how to do it in Report_ItemDataBinding event but you can as well do it in some other event
private void Report_ItemDataBinding(object sender, EventArgs e)
        {
            var report = (Telerik.Reporting.Processing.Report)sender;
            var paramValue = report.Parameters["ParamName"].Value;
        }

You can hook to some event and debug to see where the problem comes from. Kind regards,
Elian
the Telerik team