/Home /Archive /Syndicate /Blog /Support /About /Contact  
All Visual Basic Feeds in one place!





REST which stands for Representational State Transfer is a way of sending data over the Internet without an additional message layer.  Standard web services use soap for there message header.  In this example we will create a service that uses the northwind database to send a  list of the products for a category.

 

Lets start by create a new VB web application. In that web application add a Ado.Net Entities data model.  In that class add the northwind database's product class.

 

image

 

Now add a service named Service1 to the web application.  Lets start by modify the web.config for the service to support rest.  First remove the ServiceBehavior section and add a endpointBehaviors section for webHttp.  In the endpoint we have to change the binding to webHttpBinding and the behaviorConfiguration to the webBehavior we created.

 

    <system.serviceModel>
        <behaviors>
      <endpointBehaviors>
        <behavior name="webBehavior">
          <webHttp/>
        </behavior>
      </endpointBehaviors>
        </behaviors>
        <serviceHostingEnvironment aspNetCompatibilityEnabled="True"></serviceHostingEnvironment>
        <services>
            <service name="RestTest.Service1">
                <endpoint address="" behaviorConfiguration="webBehavior" binding="webHttpBinding" bindingConfiguration="" contract="RestTest.IService1">
                </endpoint>
            </service>
        </services>
    </system.serviceModel>

 

When we added the service we got 2 items the wcf service and an interface for the service.  Before we go any further we need to add a reference to system.servicebehavior.web  

 

In the Interface we need to define the how the categoryId is passed to the service.  In this example it expects product/categoryID in the url for the service

 

Imports System.ServiceModel
Imports System.ServiceModel.Web 

<ServiceContract()> _
Public Interface IService1 

    <OperationContract()> _
    <WebGet(UriTemplate:="Product/{categoryID}", ResponseFormat:=WebMessageFormat.Xml, BodyStyle:=WebMessageBodyStyle.Bare)> _
    Function GetProducts(ByVal categoryId As String) As List(Of Products) 

End Interface 

 

In the service we need to set the AspNetCompatibilityMode and write some code to return the products

 

Imports System.ServiceModel.Activation 

<AspNetCompatibilityRequirements(RequirementsMode:=AspNetCompatibilityRequirementsMode.Allowed)> _
Public Class Service1
    Implements IService1 

    Public Function GetProducts(ByVal categoryId As String) As System.Collections.Generic.List(Of Products) Implements IService1.GetProducts
        Dim dc As New NorthwindEntities
        Dim q = From p In dc.Products Select p Where p.CategoryID = CInt(categoryId)
        Return q.ToList
    End Function
End Class 

 

To call the service you would use a url like http://localhost:2050/Service1.svc/Product/7

 

you will get an xml file like this returned

 

 

image
© 2005 Serge Baranovsky. All rights reserved.
All feed content is property of original publisher. Designated trademarks and brands are the property of their respective owners.

This site is maintained by SubMain(), a division of vbCity.com, LLC