Lesson 3 - Provide Custom Editors for Report Parameters

• Aug 03, 2020
• 2 minutes to read

This example shows how you can substitute the standard parameter editors that are auto-created according to the parameter types with your own custom editors.

In this tutorial, we will use a report similar to the one created in the preceding lesson: Lesson 2 - Filter a Report on the Server using LightSwitch Query. This report obtains its parameters from a LightSwitch Query, based on which the customer list can be shown for the specified country.

According to this parameter type, XtraReports creates a text-box editor by default. To make using this parameter more convenient for end-users, you can change this editor to a ComboBoxEdit in the CustomizeParameterEditors event handler of your ReportPreviewModel.

The following code illustrates this approach.

C#

using System.Collections.Generic;
using DevExpress.Xpf.Editors;
using DevExpress.Xpf.Printing;
// ...

namespace LightSwitchApplication {
    public partial class ReportPreviewScreen {
        public void CustomizeReportPreviewModel(ReportPreviewModel model) {
            model.CustomizeParameterEditors += model_CustomizeParameterEditors;
        }

        List<object> customers;

        void model_CustomizeParameterEditors(object sender, CustomizeParameterEditorsEventArgs e) {
            if (e.Parameter.Name == "Country") {
                var editor = new ComboBoxEdit();
                editor.ItemsSource = customers;
                editor.IsTextEditable = false;
                e.Editor = editor;
                e.BoundDataMember = "EditValue";
            }
        }

        partial void ReportPreviewScreen_Activated() {
            this.ReportTypeName = "XtraReport1";
            customers = new List<object>();
            foreach (Customer customer in new DataWorkspace().NorthWind_XtraReportsData.Customers) {
                customers.Add(customer.Country);
            }
        }
    }
}

VB.NET

Imports System.Collections.Generic
Imports DevExpress.Xpf.Editors
Imports DevExpress.Xpf.Printing
' ...

Namespace LightSwitchApplication
    Partial Public Class ReportPreviewScreen
        Public Sub CustomizeReportPreviewModel(ByVal model As ReportPreviewModel)
            AddHandler model.CustomizeParameterEditors, AddressOf model_CustomizeParameterEditors
        End Sub

        Private customers As List(Of Object)

        Private Sub model_CustomizeParameterEditors(ByVal sender As Object, ByVal e As CustomizeParameterEditorsEventArgs)
            If e.Parameter.Name = "Country" Then
                Dim editor = New ComboBoxEdit()
                editor.ItemsSource = customers
                editor.IsTextEditable = False
                e.Editor = editor
                e.BoundDataMember = "EditValue"
            End If
        End Sub

        Private Sub ReportPreviewScreen_Activated()
            Me.ReportTypeName = "XtraReport1"
            customers = New List(Of Object)()
            For Each customer As Customer In New DataWorkspace().NorthWind_XtraReportsData.Customers
                customers.Add(customer.Country)
            Next customer
        End Sub
    End Class
End Namespace

The report is now ready. Run the application, choose a country and get the result.