HƯỚNG DẪN TẠO VB SERVICE JSON:

B1:
 Tạo project như sau.

B2:
Mở file IService trong thư mục App_Code và thêm dòng
Class IService:

[ServiceContract]
public interface IService
{

[OperationContract]
    [WebInvoke(Method = "POST", ResponseFormat = WebMessageFormat.Json, RequestFormat = WebMessageFormat.Json,BodyStyle=WebMessageBodyStyle.WrappedRequest)]
MyService.Service1.Persion GetData(int value);

[OperationContract]
CompositeType GetDataUsingDataContract(CompositeType composite);

// TODO: Add your service operations here
}

// Use a data contract as illustrated in the sample below to add composite types to service operations.
[DataContract]
public class CompositeType
{
bool boolValue = true;
string stringValue = "Hello ";

[DataMember]
public bool BoolValue
{
get { return boolValue; }
set { boolValue = value; }
}

[DataMember]
public string StringValue
{
get { return stringValue; }
set { stringValue = value; }
}
}


Class Service:


namespace MyService
{
    // NOTE: You can use the "Rename" command on the "Refactor" menu to change the class name "Service1" in code, svc and config file together.
    // NOTE: In order to launch WCF Test Client for testing this service, please select Service1.svc or Service1.svc.cs at the Solution Explorer and start debugging.
    public class Service1 : IService1
    {
        public Persion GetData(int value)
        {
            return new Persion() {
            ID=5,Name=""};
        }

        public CompositeType GetDataUsingDataContract(CompositeType composite)
        {
            if (composite == null)
            {
                throw new ArgumentNullException("composite");
            }
            if (composite.BoolValue)
            {
                composite.StringValue += "Suffix";
            }
            return composite;
        }
        public class Persion {
            public int ID { get;set;}
            public String Name { get; set; }
        }
    }
}

B3:
Tiếp theo là đến mục config cho service.
<?xml version="1.0"?>
<configuration>

  <appSettings>
    <add key="aspnet:UseTaskFriendlySynchronizationContext" value="true" />
  </appSettings>
  <system.web>
    <compilation debug="true" targetFramework="4.5" />
    <httpRuntime targetFramework="4.5"/>
  </system.web>
  <system.serviceModel>
    <behaviors>
      <serviceBehaviors>
        <behavior>
          <!-- To avoid disclosing metadata information, set the values below to false before deployment -->
          <serviceMetadata httpGetEnabled="true" httpsGetEnabled="true"/>
          <!-- To receive exception details in faults for debugging purposes, set the value below to true.  Set to false before deployment to avoid disclosing exception information -->
          <serviceDebug includeExceptionDetailInFaults="false"/>
        </behavior>
      </serviceBehaviors>
      <endpointBehaviors>
        <behavior>
          <webHttp/>
        </behavior>
      </endpointBehaviors>
    </behaviors>
    <protocolMapping>
        <add binding="basicHttpsBinding" scheme="https" />
    </protocolMapping>  
    <serviceHostingEnvironment aspNetCompatibilityEnabled="true" multipleSiteBindingsEnabled="true" />
    <services>
      <service name="MyService.Service1">
        <endpoint binding="webHttpBinding" contract="MyService.IService1"></endpoint>
      </service>
    </services>
  </system.serviceModel>
  <system.webServer>
    <modules runAllManagedModulesForAllRequests="true"/>
    <!--
        To browse web app root directory during debugging, set the value below to true.
        Set to false before deployment to avoid disclosing web app folder information.
      -->
    <directoryBrowse enabled="true"/>
  </system.webServer>

</configuration>

B4:
Test Service. Cài đặt restclient cho FireFox.
Download bản cài đặt tại : https://addons.mozilla.org/vi/firefox/addon/restclient/
Bặt firefox vào mục tools -> Add-ons -> Install Add-on from file.

Kết quả sau khi test.