PdfViewer.GetService<T>() Method

Gets the specified service.

Namespace: DevExpress.XtraPdfViewer

Assembly: DevExpress.XtraPdfViewer.v20.2.dll

Declaration

public T GetService<T>()
    where T : class
Public Function GetService(Of T As Class) As T

Type Parameters

Name
T

Returns

Type Description
T

A service object of the specified generic type, or a null reference (Nothing in Visual Basic) if there is no service object of this type.

Remarks

Use this method to enable your application objects to obtain a service of the PDF Viewer control, in order to employ methods of the service. The control implements the IServiceProvider interface, so you can tell it what type of service you wish to retrieve; and if a service is available, it is offered to the caller object.

There is a set of predefined services you can retrieve. The IServiceProvider and IServiceContainer interface realization allows hiding implementation details, and provides more flexibility regarding future updates of the component.

Examples

This example shows how to modify the functionality of an existing PdfViewer command.

The PdfViewer exposes the IPdfViewerCommandFactoryService interface that enables you to substitute the default command with your own custom command.

To accomplish this task:

  • Create a custom command class (e.g., a CustomNextPageCommand class), inherited from the command that you wish to replace (e.g., PdfNextPageCommand).
  • Override the required method of the command. The main functionality and command specifics are located in the Execute method.
  • Create a class (e.g., CustomPdfViewerCommandFactoryService) implementing the IPdfViewerCommandFactoryService. You should override the IPdfViewerCommandFactoryService.CreateCommand method to create an instance of a custom command class if an identifier of a certain command is passed as a parameter. So, instead of the default command, a custom command will be used by the PdfViewer.
  • Use the created class to substitute for the default PdfViewer's service.
using DevExpress.XtraPdfViewer;
using System;
using System.Windows.Forms;

namespace ViewerCustomCommand {
    public partial class Form1 : Form {

        void ReplacePdfViewerCommandFactoryService(PdfViewer control) {
            IPdfViewerCommandFactoryService service = control.GetService<IPdfViewerCommandFactoryService>();
            if (service == null)
                return;
            control.RemoveService(typeof(IPdfViewerCommandFactoryService));
            control.AddService(typeof(IPdfViewerCommandFactoryService), new CustomPdfViewerCommandFactoryService(control,service));
        }

        public Form1() {
            InitializeComponent();
            pdfViewer1.LoadDocument("..\\..\\Demo.pdf");
            ReplacePdfViewerCommandFactoryService(pdfViewer1);
        }     
    }
}
See Also