How to convert datatable to json string using json.net WCF Rest Service VB.NET

How to convert datatable to json string using json.net  WCF Rest Service

• Create WCF Service Project using C# 4.0/4.5
• Add a WCF service name it as IRestWCF

Add namespaces
using System.ServiceModel.Channels;
using System.ServiceModel.Web;

download Json.NET Add reference to   Newtonsoft.JSon  

<ServiceContract> _
    Public Interface IRestWCF
         <OperationContract> _
        <WebGet(BodyStyle = WebMessageBodyStyle.WrappedResponse, ResponseFormat =    WebMessageFormat.Json)> _
        Dim GetDataTableJson() As Message
    End Interface

 

Message class is the base class for all types of operations in WCF.

Public Class RestWCF
     Implements IRestWCF
      Public Function GetDataTableJson() As Message
          Dim dt As DataTable = GetSalesData("json")
         ' Message message = WebOperationContext.Current.CreateJsonResponse<DataTable>(dt);
         Dim strDatatable As String =  Newtonsoft.Json.JsonConvert.SerializeObject(dt)
         Return WebOperationContext.Current.CreateTextResponse(strDatatable,"application/json;charset=utf-8",System.Text.Encoding.UTF8)' Message.CreateMessage(MessageVersion.Default, "json datatable", message);
      End Function
Private Function GetSalesData(ByVal format As String) As DataTable
          Dim salesdata As DataTable =  New DataTable("SalesPerson")
          Try
              Imports (SqlConnection conn = New SqlConnection("server=(local)\sqlexpress2012database=AdventureWorks2012uid=sapwd=password&"))
              {
                  Imports (SqlDataAdapter adapter = New SqlDataAdapter("select * from (AdventureWorks2012).(Sales).(SalesPerson)", conn))
                  {
                      adapter.Fill(salesdata)

                      salesdata.AcceptChanges()
                      conn.Close()
                  }
              }
          Catch ex As SqlException
              Throw ex
          End Try
          If format = "xml" Then
              salesdata.RemotingFormat = SerializationFormat.Xml
          End If
          'else salesdata.RemotingFormat = SerializationFormat.Binary;
          Return salesdata
End Function
End Class



 

Web.Config <?xml version="1.0" encoding="utf-8"?>
<configuration>
  <configSections>
    <!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
    <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=4.4.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
  </configSections>
  <system.web>
    <compilation debug="true" targetFramework="4.0">
      <assemblies>
        <add assembly="System.Data.Entity, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
      </assemblies>
    </compilation>
  </system.web>
  <system.serviceModel>
    <behaviors>
      <serviceBehaviors>
        <behavior>
          <serviceMetadata httpGetEnabled="true" />
          <serviceDebug includeExceptionDetailInFaults="true" />
        </behavior>
        <behavior name="restbeh">
          <serviceDebug httpHelpPageEnabled="True" includeExceptionDetailInFaults="true" />
          <serviceMetadata  httpGetEnabled="True"/>
        </behavior>
      </serviceBehaviors>
      <endpointBehaviors>
        <behavior name="restendbeh">
          <!--<soapProcessing processMessages="True"/>-->
          <webHttp helpEnabled="True" faultExceptionEnabled="True"
                   defaultBodyStyle="Bare"/>
        </behavior>
      </endpointBehaviors>
    </behaviors>
    <bindings>
      <webHttpBinding>
        <binding name="myrestbinding">
          <security mode="None"></security>
          <readerQuotas maxArrayLength="65536"/>
        </binding>
      </webHttpBinding>
    </bindings>

    <services>
      <service name="WCFServicesREST.RestWCF" behaviorConfiguration="restbeh">
        <endpoint  contract="WCFServicesREST.IRestWCF" binding="webHttpBinding"  bindingConfiguration="myrestbinding"
                   behaviorConfiguration="restendbeh"></endpoint>
       
      </service>
    </services>
    <serviceHostingEnvironment multipleSiteBindingsEnabled="true"  aspNetCompatibilityEnabled="True"/>
  </system.serviceModel>
  <system.webServer>
   
    <modules runAllManagedModulesForAllRequests="true" />  </system.webServer>
  <system.web.extensions>
    <scripting>
      <scriptResourceHandler enableCaching="true" enableCompression="true" />
    </scripting>
  </system.web.extensions>
  <entityFramework>
    <defaultConnectionFactory type="System.Data.Entity.Infrastructure.LocalDbConnectionFactory, EntityFramework">
      <parameters>
        <parameter value="v11.0" />
      </parameters>
    </defaultConnectionFactory>
  </entityFramework>
</configuration>

DATATABLE JSON OUTPUT