Problem refreshing reports with params in the Interactive viewer from ASP

Question

I have a problem getting reports to refresh by clicking the Interactive Viewer's refresh button and reusing the supplied parameters. I am seeing this exact same problem on both V9.2 and 11.5 unmanaged RAS servers.
I am using the following  function code to set the reports parameters:
Public Sub PassParameter(param_index, param_value, param_is_multi,param_range_kind)
    Dim param_old ' parameter field in the report
    Dim param_new ' parameter field that will replace old parameter
Dim paramValue ' discrete parameter value
Dim aValues
Dim rValues
Dim iLoop
Set param_old = clientDoc.DataDefinition.ParameterFields.Item(param_index)
Set param_new = objFactory.CreateObject("CrystalReports.ParameterField";)
If param_range_kind = 1 then
Set paramValue = objFactory.CreateObject("CrystalReports.ParameterFieldDiscreteValue";)
paramValue.Value = param_value
else
Set paramValue = objFactory.CreateObject("CrystalReports.ParameterFieldRangeValue";)
     rValues = split(param_value, "|")
paramValue.BeginValue = rValues(0)
paramValue.EndValue = rValues(1)
paramValue.LowerBoundType = 2
paramValue.UpperBoundType = 2
end if
param_old.CopyTo param_new
if param_is_multi = 0 then
param_new.CurrentValues.Add paramValue
else
     aValues = split(param_value, ",")
   For iLoop = LBound(aValues) to UBound(aValues)
param_new.CurrentValues.Add Trim(aValues(iLoop))
    Next
end if
clientDoc.DataDefController.ParameterFieldController.Modify param_old, param_new
    ' Clean up
    Set paramValue = Nothing
    Set param_new = Nothing
End Sub
and then redirecting to another ASP page to invoke the viewer (the report "clientDoc" object is passed to the viewer asp page a s a session variable). The code of the viewer page is:
<%
Response.ExpiresAbsolute = Now() - 1
Response.Charset=";UTF-8"
Dim clientDoc
Set clientDoc = session("clientDoc")
Dim ObjFactory, RptAppSession
Set ObjFactory = CreateObject("CrystalReports.ObjectFactory";)
Dim viewer
Set viewer = ObjFactory.CreateObject("CrystalReports.CrystalReportInteractiveViewer";)
viewer.PageTitle = "Interactive Report - " & Request("rptnam")
viewer.IsOwnForm = true
viewer.IsOwnPage = true
viewer.HasRefreshButton = true
viewer.EnableParameterPrompt = false
viewer.ReuseParameterValuesOnRefresh ; = true
viewer.HasExportButton = false
' viewer.HasPrintButton = false
viewer.ReportSource = clientDoc.ReportSource
Dim BooleanSearchControl
Set BooleanSearchControl = ObjFactory.CreateObject("CrystalReports.BooleanSearchControl";)
BooleanSearchControl.ReportDocument = clientDoc
viewer.BooleanSearchControl = BooleanSearchControl
viewer.ProcessHttpRequest Request, Response, Session
%>
If I set viewer.EnableParameterPrompt = false then I get an erro upon clicking the viewer's refresh button (error is: Missing parameter values. webReporting.dll error '8004100e' ), but if I set viewer.EnableParameterPrompt = true, then I get the automatically generated prompts appear but they are all empty. Either way, RAS doesn't remember the supplied parameters. I know the parameters are being read by RAS as the report's contents prove this fact, but they are not remembered after refreshing. If the automatically generated prompts are filled in and submitted, subsequent refreshes work correctly.
How do I get the report viewer to reuse the parameters that have been set programmatically after a refresh? BTW, changing my implementation to anything other than using ASP against an unmanaged RAS server is not an option at this time.
Thanks in advance!
Dave.

Answer 1

Hi Dave,
I don't have a "nice" set of code lines but below hard codes one parameter name and value:
            ISCRParameterField newParameterField = new ParameterFieldClass();
            newParameterField.ParameterType = crParameterFieldTypeEnum.crParameterFieldTypeReportParameter;
            newParameterField.Name = "YourParamName"; // you can make a collection here
            newParameterField.ReportName = "";
            newParameterField.Type = CrFieldValueTypeEnum.crFieldValueTypeStringField;
            newParameterField.AllowMultiValue = true;
            newParameterField.AllowCustomCurrentValues = true;
            Fields parameterFields = reportClientDocument.DataDefinition.ParameterFields;
            ISCRField existingParameterField;
            RowsetMetaData rowsetMetaData = new RowsetMetaDataClass();
            Fields fields = new FieldsClass();
            ArrayList defaultValues = new ArrayList();
            reportClientDocument.DataDefController.ParameterFieldController.SetCurrentValue("", @"YourParamName", @"YourParamValue");
Thanks again
Don