How to: Access the Report Parameters Object in Calculated Fields Expressions

• Oct 09, 2020
• 2 minutes to read

This topic describes how you can access data of a report parameters object (inherited from ReportParametersObjectBase and specified using IReportDataV2.ParametersObjectType) in calculated field expressions.

Override the Parameters Object’s ToString method.

C#

public class DemoParameters : ReportParametersObjectBase {
    // ...
    public override string ToString() {
        return City;
    }
}

VB.NET

Public Class DemoParameters
    Inherits ReportParametersObjectBase
    ' ...
    Public Overrides Function ToString() As String
        Return City
    End Function
End Class

As a result, you can refer to the ToString result with the “[Parameters.XafReportParametersObject]” expression, e.g.:

Concat([Full Name],' from ', [Parameters.XafReportParametersObject])

Alternatively, you can create a report script, handle the GetValue event of a certain field and then access a parameter value as demonstrated in the How to: Access the Report Parameters Object in Report Scripts topic.

C#

private void calculatedFieldCity_GetValue(object sender, DevExpress.XtraReports.UI.GetValueEventArgs e) {
    DevExpress.XtraReports.Parameters.Parameter param =
            (DevExpress.XtraReports.Parameters.Parameter)
                ((DevExpress.XtraReports.UI.XtraReport)e.Report).Parameters["XafReportParametersObject"];
    if (param != null) {
        ReportV2Demo.Module.BusinessObjects.Contact contact = 
        (ReportV2Demo.Module.BusinessObjects.Contact)e.Row;
        ReportV2Demo.Module.Reports.DemoParameters xafParameter =
            (ReportV2Demo.Module.Reports.DemoParameters)param.Value;
        e.Value = contact.FullName + " from " + xafParameter.City;
    }
}

VB.NET

Private Sub calculatedFieldCity_GetValue(ByVal sender As Object, ByVal e As DevExpress.XtraReports.UI.GetValueEventArgs)
    Dim param As DevExpress.XtraReports.Parameters.Parameter = _
    CType(((DevExpress.XtraReports.UI.XtraReport)e.Report).Parameters("XafReportParametersObject"), _
    DevExpress.XtraReports.Parameters.Parameter)
    If param IsNot Nothing Then
        Dim contact As ReportV2Demo.Module.BusinessObjects.Contact = _
        CType(e.Row, ReportV2Demo.Module.BusinessObjects.Contact)
        Dim xafParameter As ReportV2Demo.Module.Reports.DemoParameters = _
        CType(param.Value, ReportV2Demo.Module.Reports.DemoParameters)
        e.Value = contact.FullName & " from " & xafParameter.City
    End If
End Sub