trouble in passing parameter in crystal document

[aguest]

i am getting some trouble with a tutorial that i found on msdn web site : http://msdn.microsoft.com/en-us/library/ms227722.aspx. i would like to pass a parameter to my CrystalReport document,but i would like to send an integer value to my CR document and just one value(because in the tut its sending and array of string values). the code is the fellowing

Private Const PARAMETER_FIELD_NAME As String = "numb"

Private impbonrecepReport As ReportDocument

Private Sub ConfigureCrystalReports()


    Dim myArrayList As ArrayList = New ArrayList()

    myArrayList.Add(999)
    Dim numbrecep As Integer

    numbrecep = 999



    SetCurrentValuesForParameterField(impbonrecepReport, myArrayList)
   
    impbonrecepReport = New ReportDocument()
    Dim reportPath As String = Application.StartupPath & "\\" & "ImpBonReception.rpt"

    impbonrecepReport.Load(reportPath)
    CrystalReportViewer1.ReportSource = impbonrecepReport

End Sub

Private Sub SetCurrentValuesForParameterField(ByVal myReportDocument As ReportDocument, ByVal myArrayList As ArrayList)

    Dim currentParameterValues As ParameterValues = New ParameterValues()


    For Each submittedValue As Object In myArrayList

        Dim myParameterDiscreteValue As ParameterDiscreteValue = New ParameterDiscreteValue()
        myParameterDiscreteValue.Value = myArrayList.ToString()
        currentParameterValues.Add(myParameterDiscreteValue)

    Next


    Dim myParameterFieldDefinitions As ParameterFieldDefinitions = myReportDocument.DataDefinition.ParameterFields
    Dim myParameterFieldDefinition As ParameterFieldDefinition = myParameterFieldDefinitions(PARAMETER\_FIELD\_NAME)
    myParameterFieldDefinition.ApplyCurrentValues(currentParameterValues)


End Sub

i got this error message

An unhandled exception of type 'System.NullReferenceException' occurred in GestionStock.exe
Additional information: La référence d'objet n'est pas définie à une instance d'un objet.

in this line Dim myParameterFieldDefinitions As ParameterFieldDefinitions = myReportDocument.DataDefinition.ParameterFields can you help me to solve this problem? thank you

[Tom Deketelaere]

The error is telling you that the object isn't initialized. And it is right. Change your code to the following:

    impbonrecepReport = New ReportDocument()
    Dim reportPath As String = Application.StartupPath & "\\" & "ImpBonReception.rpt"
impbonrecepReport.Load(reportPath)

SetCurrentValuesForParameterField(impbonrecepReport, myArrayList)

    CrystalReportViewer1.ReportSource = impbonrecepReport

Initialize and load your report first, then set the parameter value's and then show it. You'll also have to change

ByVal myReportDocument As ReportDocument

to

ByRef myReportDocument As ReportDocument

Or make the sub into a function and return the report at the end. Basicly you passed an empty object to the 'SetCurrentValuesForParameterField'.