How to: Print a Report Without Displaying a Preview

• Oct 17, 2023
• 5 minutes to read

This topic describes how to implement the PrintContacts Action, which prints the “Contacts Report” report without displaying its preview. Note that this Action is not designed for reports with end-user-specified parameters (reports that use ReportParametersObjectBase parameters or native XtraReport parameters).

You can also use the code from this example to access an XtraReport object and then export or email the report content as illustrated in the tutorials listed in the Exporting Reports document.

We recommend that you review the following XtraReports help topics and examples before you proceed:

• Printing a Report
• Printing and Export in Reporting Tools for Web
• How to print a report without displaying it in a web application

Tip

A complete sample project is available in the DevExpress Code Examples database at https://supportcenter.devexpress.com/ticket/details/e5146/xaf-how-to-print-a-report-without-displaying-a-preview.

In this topic, it is assumed that you have an XAF application that uses the Reports V2 Module, and you have created one or more reports (see Reports V2 Module Overview).

Create the PrintContacts Action in an Abstract Platform-Agnostic Controller

In the application’s main module project, implement the following abstract Controller class.

File: MySolution.Module/Controllers/PrintContactsController.cs

C#

using DevExpress.ExpressApp;
using DevExpress.ExpressApp.Actions;
using DevExpress.Persistent.Base;
using MySolution.Module.BusinessObjects;
// ...
public abstract class PrintContactsController : ObjectViewController<ListView, Contact> {
    public PrintContactsController() {
        SimpleAction printAction = new SimpleAction(this, "PrintContacts", PredefinedCategory.Reports);
        printAction.ImageName = "Action_Printing_Print";
        printAction.Execute += delegate (object sender, SimpleActionExecuteEventArgs e) {
            PrintReport("ContactReport", e.SelectedObjects);
        };
        }
    protected abstract void PrintReport(string reportDisplayName, System.Collections.IList selectedObjects);
}

As you can see, the PrintContactsController targets Contact objects, so it will be activated when a user selects Contact in the navigation. The Controller introduces the PrintContacts SimpleAction. The abstract PrintReport method is called when the Action is executed (see SimpleAction.Execute). This method takes two parameters:

reportDisplayName

The display name of a report to print. Implementations will use this value to find the specified report in the report storage.

selectedObjects

The list of objects selected in the List View. Implementations will use this information to filter printed reports.

The next two sections explain how to implement the PrintReport method in WinForms and ASP.NET Core Blazor projects.

Implement Report Printing for WinForms

In the WinForms module project, inherit the PrintContactsController. If your solution does not contain this project, add the Controller to the WinForms application project. In the Controller, implement the PrintReport method in the following manner:

File: MySolution.Win/Controllers/WinInstantPrintReportController.cs

C#

using DevExpress.Data.Filtering;
using DevExpress.ExpressApp;
using DevExpress.ExpressApp.ReportsV2;
using DevExpress.Persistent.BaseImpl.EF;
using DevExpress.Xpo;
using DevExpress.Xpo.DB;
using DevExpress.XtraReports.UI;
using InstantPrintReportsV2Example.Module.Controllers;
using Microsoft.Extensions.DependencyInjection;
// ...
public class WinInstantPrintReportController : PrintContactsController {
    readonly IReportExportService reportExportService;
    public WinInstantPrintReportController() : base() { }

    [ActivatorUtilitiesConstructor]
    public WinInstantPrintReportController(IServiceProvider serviceProvider) : base() { 
        reportExportService = serviceProvider.GetRequiredService<IReportExportService>();
    }

    protected override void PrintReport(string reportDisplayName, System.Collections.IList selectedObjects) {
        using XtraReport report = reportExportService.LoadReport<ReportDataV2>(r => r.DisplayName == reportDisplayName);
        // Filter and sort report data.
        CriteriaOperator objectsCriteria = ((BaseObjectSpace)ObjectSpace).GetObjectsCriteria(((ObjectView)View).ObjectTypeInfo, selectedObjects);
        SortProperty[] sortProperties = { new SortProperty("Age", SortingDirection.Descending) };
        reportExportService.SetupReport(report, objectsCriteria.ToString(), sortProperties);
        report.PrintDialog();
    }
}

The Controller implementation injects the IReportExportService. The following API available through this service is used:

IReportExportService.LoadReport

Searches for a report in the report storage based on the specified criteria and loads the found report’s data from the storage.

IReportExportService.SetupReport

Initializes the specified report. The above code sample uses an overload of this method that also filters and sorts report data.

The XtraReport‘s PrintDialog extension method is then called to invoke a print dialog. An end user can specify a printer and other print options before the document is printed.

Important

Ensure that the DevExpress.XtraPrinting.v23.2.dll assembly is referenced. The PrintDialog extension method is implemented in this assembly.

The result is demonstrated in the image below.

Implement Report Printing for ASP.NET Core Blazor (Export a Report to a PDF File)

In the ASP.NET Core Blazor project, add the following JavaScript code to Pages/_Host.cshtm:

File: MySolution.Blazor.Server/Pages/_Host.cshtml

Razor

<!DOCTYPE html>
<html lang="en">
...
<body>
    ...
    <script>
        window.downloadFileFromStream = async (fileName, contentStreamReference) => {
            const arrayBuffer = await contentStreamReference.arrayBuffer();
            const blob = new Blob([arrayBuffer]);
            const url = URL.createObjectURL(blob);
            const anchorElement = document.createElement('a');
            anchorElement.href = url;
            anchorElement.download = fileName ?? '';
            anchorElement.click();
            anchorElement.remove();
            URL.revokeObjectURL(url);
        }
    </script>
</body>

The downloadFileFromStream function forces a user’s browser to download an exported report file from the specified stream.

Inherit the PrintContactsController. In the Controller, implement the PrintReport method in the following manner:

File: MySolution.Blazor.Server/Controllers/BlazorPrintContactsController.cs

C#

using DevExpress.Data.Filtering;
using DevExpress.Data.Helpers;
using DevExpress.ExpressApp;
using DevExpress.ExpressApp.ReportsV2;
using DevExpress.Persistent.BaseImpl.EF;
using DevExpress.Xpo;
using DevExpress.XtraReports.UI;
using InstantPrintReportsV2Example.Module.Controllers;
using Microsoft.JSInterop;
using DevExpress.Xpo.DB;
using DevExpress.ReportServer.ServiceModel.DataContracts;
using Microsoft.Extensions.DependencyInjection;
// ...
public class BlazorPrintContactsController : PrintContactsController {
    readonly IReportExportService reportExportService;
    readonly IJSRuntime jsRuntime;
    public BlazorPrintContactsController() : base() { }

    [ActivatorUtilitiesConstructor]
    public BlazorPrintContactsController(IServiceProvider serviceProvider) : base() {
        reportExportService = serviceProvider.GetRequiredService<IReportExportService>();
        jsRuntime = serviceProvider.GetRequiredService<IJSRuntime>();
    }

    protected override async void PrintReport(string reportDisplayName, System.Collections.IList selectedObjects) {
        using XtraReport report = reportExportService.LoadReport<ReportDataV2>(r => r.DisplayName == reportDisplayName);
        // Filter and sort report data
        CriteriaOperator objectsCriteria = ((BaseObjectSpace)ObjectSpace).GetObjectsCriteria(((ObjectView)View).ObjectTypeInfo, selectedObjects);
        SortProperty[] sortProperties = { new SortProperty("Age", SortingDirection.Descending) };
        reportExportService.SetupReport(report, objectsCriteria.ToString(), sortProperties);

        using Stream s = reportExportService.ExportReport(report, DevExpress.XtraPrinting.ExportTarget.Pdf);
        using var streamRef = new DotNetStreamReference(s);
        var fileName = reportDisplayName + ".pdf";
        await jsRuntime.InvokeVoidAsync("downloadFileFromStream", fileName, streamRef);
    }
}

The controller’s PrintReport method implementation injects the IReportExportService and uses the same API of this service as the WinForms controller implementation with the addition of the following method:

IReportExportService.ExportReport

Exports the specified report to the specified format and returns a Stream that can be used to read the exported report data.

A reference to the stream returned by the ExportReport method is passed to the downloadFileFromStream JavaScript function to force the browser to download an exported .pdf file from this stream.

The result is demonstrated in the image below.