Learn More





DNN Community Blog

The Community Blog is a personal opinion of community members and by no means the official standpoint of DNN Corp or DNN Platform. This is a place to express personal thoughts about DNNPlatform, the community and its ecosystem. Do you have useful information that you would like to share with the DNN Community in a featured article or blog? If so, please contact .

The use of the Community Blog is covered by our Community Blog Guidelines - please read before commenting or posting.

Creating A DotNetNuke ASP.NET AJAX Web Service

This article will cover what is needed to implement web services for use with ASP.NET AJAX in the DotNetNuke Framework. It uses code from the Microsoft ASP.NET AJAX site ( that was converted to use as a DotNetNuke module.

Also, see this post: Creating A DotNetNuke Module using ASP.NET AJAX for an overview of AJAX functionality with DotNetNuke and Creating Secure DotNetNuke ASP.NET AJAX Web Services for creating secure web services.

The Problem

Looking at the Microsoft ASP.NET AJAX tutorial, you will see example code such as this:

           path="~/WebServices/SimpleWebService.asmx" />

The problem is that you cannot use this code with a DotNetNuke module. If you do you will get this error:

Unhandled error loading module.
DotNetNuke.Services.Exceptions.ModuleLoadException: Unhandled Error Adding Module to ContentPane ---> System.InvalidOperationException: Only one instance of a ScriptManager can be added to the page. at System.Web.UI.ScriptManager.OnInit(EventArgs e) at System.Web.UI.Control.InitRecursive(Control namingContainer) at System.Web.UI.Control.InitRecursive(Control namingContainer) at System.Web.UI.Control.InitRecursive(Control namingContainer) at System.Web.UI.Control.InitRecursive(Control namingContainer) at System.Web.UI.Control.InitRecursive(Control namingContainer) at System.Web.UI.Control.AddedControl(Control control, Int32 index) at System.Web.UI.ControlCollection.Add(Control child) at DotNetNuke.UI.Skins.Skin.InjectModule(Control objPane, ModuleInfo objModule, PortalSettings PortalSettings) --- End of inner exception stack trace ---

The reason is that the DotNetNuke Framework injects the Script manager for you and only one script manager can be placed on a page at one time.

The Solution

In the example code (VB / C#), there is a DotNetNuke user control (View.ascx) that has a JavaScript file (CallWebServiceMethods.js) and a web service (WebService.asmx).

First, in the Page_Load method, obtain an instance of the ScriptManager:


Dim objScriptManager As ScriptManager = ScriptManager.GetCurrent(Me.Page)


ScriptManager objScriptManager = ScriptManager.GetCurrent(this.Page)

and then set your properties:


Dim objServiceReference As ServiceReference = New ServiceReference
objServiceReference.Path = "~/DesktopModules/AjaxWebService/WebService.asmx"

Dim objScriptReference As ScriptReference = New ScriptReference
objScriptReference.Path = "~/DesktopModules/AjaxWebService/CallWebServiceMethods.js"


ServiceReference objServiceReference = new ServiceReference();
objServiceReference.Path = @"~/DesktopModules/AjaxWebService/WebService.asmx";

ScriptReference objScriptReference = new ScriptReference();
objScriptReference.Path = @"~/DesktopModules/AjaxWebService/CallWebServiceMethods.js";

Secure Web Services

You may notice that the web service included with the sample code does not have any security and will return the same data no mater what portal the module is used on. This would not be very usable in a real world application. Most of the issues of providing security and making a web service portal specific have been implemented in the IWEB project. The code is free and it even provides a configuration screen for your web methods. See: Creating Secure DotNetNuke ASP.NET AJAX Web Services

Download the sample code here [VB] [C#]


Comment Form

Only registered users may post comments.


2sic Daniel Mettler (124)
Aderson Oliveira (15)
Alec Whittington (11)
Alex Shirley (10)
Andrew Nurse (30)
Anthony Glenwright (5)
Antonio Chagoury (28)
Ash Prasad (21)
Ben Schmidt (1)
Benjamin Hermann (25)
Benoit Sarton (9)
Beth Firebaugh (12)
Bill Walker (36)
Bob Kruger (5)
Brian Dukes (2)
Brice Snow (1)
Bruce Chapman (20)
Bryan Andrews (1)
cathal connolly (55)
Charles Nurse (163)
Chris Hammond (203)
Chris Paterra (55)
Clinton Patterson (28)
Cuong Dang (21)
Daniel Bartholomew (2)
Dave Buckner (2)
David Poindexter (3)
David Rodriguez (2)
Doug Howell (11)
Erik van Ballegoij (30)
Ernst Peter Tamminga (74)
Geoff Barlow (6)
Gifford Watkins (3)
Gilles Le Pigocher (3)
Ian Robinson (7)
Israel Martinez (17)
Jan Blomquist (2)
Jan Jonas (3)
Jaspreet Bhatia (1)
Jenni Merrifield (6)
Joe Brinkman (269)
John Mitchell (1)
Jon Henning (14)
Jonathan Sheely (4)
Jordan Coopersmith (1)
Joseph Craig (2)
Kan Ma (1)
Keivan Beigi (3)
Ken Grierson (10)
Kevin Schreiner (6)
Leigh Pointer (31)
Lorraine Young (60)
Malik Khan (1)
Matthias Schlomann (15)
Mauricio Márquez (5)
Michael Doxsey (7)
Michael Tobisch (3)
Michael Washington (202)
Mike Horton (19)
Mitchel Sellers (28)
Nathan Rover (3)
Navin V Nagiah (14)
Néstor Sánchez (31)
Nik Kalyani (14)
Peter Donker (52)
Philip Beadle (135)
Philipp Becker (4)
Richard Dumas (22)
Robert J Collins (5)
Roger Selwyn (8)
Ruben Lopez (1)
Ryan Martinez (1)
Salar Golestanian (4)
Sanjay Mehrotra (9)
Scott McCulloch (1)
Scott S (11)
Scott Wilkinson (3)
Scott Willhite (97)
Sebastian Leupold (80)
Shaun Walker (237)
Shawn Mehaffie (17)
Stefan Cullmann (12)
Stefan Kamphuis (12)
Steve Fabian (31)
Timo Breumelhof (24)
Tony Henrich (3)
Torsten Weggen (2)
Vicenç Masanas (27)
Vincent Nguyen (3)
Vitaly Kozadayev (6)
Will Morgenweck (37)
Will Strohl (163)
William Severance (5)
Try Evoq
For Free
Start Free Trial
a Demo
See Evoq Live
Need More Information?