.NET Tutorials, Forums, Interview Questions And Answers
Welcome :Guest
Sign In
Win Surprise Gifts!!!

Top 5 Contributors of the Month
david stephan
Gaurav Pal
Post New Web Links

Expose DataTable from WCF service, all Generic lists convert to arrays

Posted By:      Posted Date: August 29, 2010    Points: 0   Category :WCF
I added a method to a .Net 3.5 WCF web service that returns a DataTable.  Other methods in the web service return Generic lists and/or take Generic lists as parameters.  When I update my reference to the altered web service from my client application all generic lists used as parameters or return types from all methods in the web service are converted to arrays.  In my service reference settings I have selected "System.Collections.Generic.List."  Apparently this setting has no effect when a web service returns a DataTable? Is there any way to prevent this from occuring? Steps to reproduce: Create a web service with methods that return Generic lists and/or take Generic lists as parameters. In a client application reference the web service and select "System.Collections.Generic.List" as the collection type.  Verify that return types/parameter types are generic lists. Add a method to the web service that returns a DataTable.  In a client application update the service reference. Note that all Generic lists (either as return types or method parameters) have changed to arrays.  This occurs even though the collection type service reference setting remains as "System.Collections.Generic.List".  Tom Regan

View Complete Post

More Related Resource Links

Convert WCF service to self hosting application


 I created project as a  WCF Service application and now according to recuriment that needs to be converted as a self hosting application

How can i do this?

Converting WCF service app to Self hosting app?

C++ and ATL: Use ATL Server Classes to Expose Your Unmanaged C++ Code as an XML Web Service


Throughout this issue, you'll read all about the promise of Web Services and how the .NET Framework enables Web Service development. Many people will also be building their Web Services atop C++ code and frameworks like ATL Server, particularly when performance is paramount. In this article, the authors show how fully functional Web Services are built using ATL Server and Visual Studio .NET. Beginning with unmanaged C++ classes, they add ATL attributes that make the code work over HTTP.

Kirk Fertitta and Chris Sells

MSDN Magazine December 2002

Cannot delete rows in a list via Lists web service's UpdateListItems-function, even though I am abl

Hi all, I'm trying to delete some rows in a SharePoint 2010 Foundation list via Lists.asmx -web service's UpdateListItems. The web service is called from BizTalk. I am able to create rows, but for some reason delete fails. I also use "GetListItems"-function without problems. The exception I get is Microsoft.SharePoint.SoapServer.SoapServerException. The message is "Cannot access a closed Stream." The updates-element of the UpdateListItems-function is as follows (well, a part of it, the real one has more Method-elements, but you get the gist..): <Batch OnError="Continue" ListVersion="1"> <Method ID="1" Cmd="Delete"> <Field name="ID">1900</Field> <Field name="IMEI">GFA-687</Field> </Method> <Method ID="2" Cmd="Delete"> <Field name="ID">1901</Field> <Field name="IMEI">OVG-567</Field> </Method> <Method ID="3" Cmd="Delete"> <Field name="ID">1902</Field> <Field name="IMEI">OXI-570</Field> </Method> </Batch> I've also tried that Batch without the IMEI-information, as well as with a valid ViewName. Why cannot I delete when I can clearly modify/create rows - what's up with th

Convert .NET web service to J2EE Web Service

Hi Are there any tools/process available to convert a .net webservice to j2ee web service. One of my project requires this migration. would be easy if there are any opensource or Java/Sun supported tools available for this task. Please let me know of any resources. Thanks

Field CLR Types via Lists Web Service

I have an app that is retrieving list data via the Lists web service.  Currently, all data is returned as a string in a DataTable.  This works ok, but it doesn't work with the charting tool, which needs values of type int or float.  So I set the column types based on http://msdn.microsoft.com/en-us/library/ms131092.aspx and http://msdn.microsoft.com/en-us/library/ms437580(v=office.12).aspx.  For example, if the field type is Number, then I set the DataColumn type to Double.  But now, certain values cause exceptions because the returned value doesn't parse to the documented type.  For example, Lookup type fields are documented to be stored as int types, but the actual values returned are like "1;#". Does anyone have some advice about how to do this?  I have a big switch statement that checks the field type, and sets the DataColumn type according to the documentation, and I'm thinking of reducing it so that it only sets some of the types, for instance, Number and DateTime, but leaves the rest as string types.my blog - Tea Time with Meowkins

How to expose an enum type to a client via WCF if it isn't used as a param type in any service oper

Hi,   I want to 'expose' an enum type from my server via WCF so that my client can access it. This happens automagically if I use the enum as a parameter type within a service operation, however, what if the particular enum isn't part of any service operation?   In other words, I've defined serveral enums within my Server that are quite useful to my client (even though they don't appear in any of my paramter declarations for the service operations).   The only way I can get this to work is simply create dummy service operations that contains these enum's as arguments. The MEX page then exposes these types for my client to use, but this seems a bit naff.   Thanks   Paul.

Update Managed Metadata Field with using Lists.asmx service

Hello! I am trying to update Managed Metadata Field with using Lists.asmx. I know that I must use this format WSSID;#VALUE|GUID. But I don't Know how I can get WSSID and VALUE Guid! Can I get them with using lists.asmx! Thanks!!

How to expose app.config or binding properties for web service

I have a project that consumes a web service, which is then bundled into a windows service and a deployment project.  Both the project consuming the web service (I'll call that the vendorcontrol) and the service project have app.config files in the project structure, but when I compile and deploy, the settings for the vendorcontrol are not accessible in the resulting project.exe.config file.  How would I make this happen?

Generic List to DataTable



I have a GenericList and i want to convert that to DataTable

My code is here

Dim queryF = From FinOpeningRegisterBranch In db1.FinOpeningRegisterBranches Where FinOpeningRegisterBranch.YearID = AccountLoginYearID.ToString And FinOpeningRegisterBranch.BranchCode = getBranchCode(txtBranch.Text, Me.Context) 
objFinOpRegs = CType(queryF.ToList(), List(Of FinOpeningRegisterBranch))

I am getting Count in "objFinOpRegs". But i want to convert "objFinOpRegs " to DataTable.


How To convert existing web service to WCF Service


Hi All,

I have running existing web service in framework 2.0, but i want to convert all my service to framework 3.5 WCF Service..


Help Me what kind of steps i'll do ?



Ashwani Kumar 

Creating a generic template writer that can handle drop downs and option lists


If I have a the following model

public class User
		public List<Company> Companies;
		public string Login { get; set; }

		[DisplayName("First Name")]
		public string FirstName { get; set; }

		[DisplayName("Last Name")]
		public string LastName { get; set; }

		public string Password { get; set; }

		private int Company { get; set; }

And the following generic control template writer (which would have to be extended appropriately)

<%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl" %>
<% foreach (var prop in ViewData.ModelMetadata.Properties .Where(pm => pm.ShowForEdit && !ViewData.TemplateInfo.Visited(pm))) 
{ %>
	<div class="SD_FieldItem">
		<% if (!String.IsNullOrEmpty(Html.Label(prop.PropertyName).ToHtmlString()))
			switch (prop.ModelType.Name)
				case "Boolean":

						<div class="SD_BoolField">
							<%= Html.CheckBox(prop.PropertyName) %>
							<%= Html.Label(prop.PropertyName) %>
							<%= Html.ValidationMessage(prop.PropertyName, 

svcutil /metadata - how to export metadata for service contract that has generic type



I am using svcutil /metadata to get metadata for a WCF service project assembly, the service class implements the IChildServiceContract below, and the IChildServiceContract interface implements a base interface which accept a generic type.

public interface IChildServiceContract : IServiceBaseContract<string>

I can generate metadata for IChildServiceContract , I am curious and also want to try generate meta data for base interface, an error come up which seems have problem with the generic based contract:

There was an error exporting the contract loaded from the type: xxx.xxx.xxx.IServiceBaseContract`1

Is it possible to generate metadata in this situation?


Thanks in advanced


How to convert DataTable objects to IList without using For Each Loop


DataTable result = GetDataSetByQuery(query).Tables[0]
IList<string> li=new IList<string>();

Can we implement through LINQ ?

How can i convert my datatable into XML using C# 2.0?



I have a datatable in asp.net 2.0 and C# as Code behind. My question is how can i convert this datatable into XML and save it to my project directory. And How can i call it back from its location into any dataset, datatable, and how can i query this XML..?

Give example with code please...


How to return datatable from a typed dataset using WCF service and Jun CTP ?


How to return datatable from a typed dataset using WCF service/



       In one of my application I am using the Typed Dataset that contains many tables. I want to return a particular Datatable form the dataset as following.


Case 1. The following code is working, but the problem is I can not use .EnforceConstraints = false property as this property only available with Dataset.  (I want to use this property because I want to return only selected fields from the table and rest of the fields may have not null columns)

Convert 'Windows Application' to 'Windows Service' .... imposible?


Hi all!

I want run my server application as system service, but i starts the project as 'Windows Application' ... how to convert it now to 'Windows Service' ? :S

I try to add the component "Windows Service", and change the "Application type" to 'Windows Service', but i can't select 'Service1' as my "Startup Object", then when i register de service and launch it from the "Services" magnagement mmc  ... die at 30 seconds because the services mmc can't comunicate with it :(

Nevertheless, if i create a new project like 'Windows Service' runs ok.



WCF Service returning DataTable for silverlight client



I am creating a WCF 3.0 service which will fetch data from the database and return mostly in DataTable and DataSet format. I am building a Silverlight client for consuming this service. But what I found is Silverlight 3.0 does not support datatable or dataset. Unfortunately most of my datas are returned in the datatable format. Is there any way to consume datatable in silver light or converting datatable to generic list or LINQ before returning them? If it is possible to convert datatable to generic collection, does it possible without iteration? This is because converting hundreds of records by iterating will affect my performance.

Thanks in Advance!!!!

Best regards,
Subalakshmi Vijayarajan.

Subalakshmi Vijayarajan.
ASP.NetWindows Application  .NET Framework  C#  VB.Net  ADO.Net  
Sql Server  SharePoint  Silverlight  Others  All   

Hall of Fame    Twitter   Terms of Service    Privacy Policy    Contact Us    Archives   Tell A Friend