How to Build a REST Service Using WCF

The below code gives a server implementation of building a REST Service using WCF.

[ServiceContract]
public interface IService1
{
    [WebGet]
    string GetData();
 
    [WebGet]
    string GetDataFromValue(int value);
 
    [WebInvoke]
    CompositeType GetDataUsingDataContract(SampleItem sample);
 
    [WebInvoke]
    XElement GetDataFromString(XElement xmlString);
 
    [WebInvoke]
    string GetDataFromStringAsString(string xmlString);
}

[AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Required)]
[KnownType(typeof(CompositeType))]
public class Service1 : IService1
{
    public string GetData()
    {
        return "Welcome to server";
    }
 
    public string GetDataFromValue(int value)
    {
        return string.Format("You entered: {0}", value);
    }
 
    public SampleItem GetDataUsingDataContract(SampleItem sample)
    {
        if (sample == null)
        {
            throw new ArgumentNullException("sample");
        }
        if (sample.BoolValue)
        {
            sample.StringValue += "Suffix";
        }
        return sample;
    }
 
    public XElement GetDataFromString(XElement xmlString)
    {
        xmlString.Name = xmlString.Name + "_modified";
        return xmlString;
    }
 
    public string GetDataFromStringAsString(string xmlString)
    {
        if (xmlString.Length > 0)
            return "Hello World";
        return "No String";
    }
 
    public string GetDataFromStrings()
    {
        string xmlString = HttpContext.Current.Request.Form["xmlString"];
        string strXml = HttpContext.Current.Request.Form["strXml"];
        if (xmlString.Length > 0 && strXml.Length > 0)
            return xmlString + strXml + " appended from server";
        return "Either of the string is empty";
    }
}

The AspNetCompatiblity mode is set to access the HttpContext. in the GetDataFromStrings() method.

Also we can build the same Rest service in an MVC style as shown below:

[ServiceContract]
[AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)]
[ServiceBehavior(InstanceContextMode = InstanceContextMode.PerCall)]
public class RestService
{
    // TODO: Implement the collection resource that will contain the SampleItem instances
    private static List<SampleItem> sampleCollection = new List<SampleItem>();
    [WebGet]
    public List<SampleItem> GetCollection()
    {
        // TODO: Replace the current implementation to return a collection of SampleItem instances
        if (sampleCollection.Count == 0)
        {
            sampleCollection = new List<SampleItem>();
            sampleCollection.Add(new SampleItem() { Id = 1, StringValue = "Hello 1" });
            sampleCollection.Add(new SampleItem() { Id = 2, StringValue = "Hello 2" });
            sampleCollection.Add(new SampleItem() { Id = 3, StringValue = "Hello 3" });
            sampleCollection.Add(new SampleItem() { Id = 4, StringValue = "Hello 4" });
            sampleCollection.Add(new SampleItem() { Id = 5, StringValue = "Hello 5" });
        }
        return sampleCollection;
    }
 
    [WebInvoke]
    public SampleItem Create(SampleItem instance)
    {
        sampleCollection.Add(instance);
        return instance;
    }
 
    [WebGet(UriTemplate = "{id}")]
    public SampleItem Get(string id)
    {
        // TODO: Return the instance of SampleItem with the given id
        return sampleCollection.Where(i => i.Id == Convert.ToInt32(id)) as SampleItem;
    }
 
    [WebInvoke(UriTemplate = "{id}", Method = "PUT")]
    public SampleItem Update(string id, SampleItem instance)
    {
        SampleItem objSample = sampleCollection.Where(i => i.Id == Convert.ToInt32(id)) as SampleItem;
        objSample = instance;
        return objSample;
    }
 
    [WebInvoke(UriTemplate = "{id}", Method = "DELETE")]
    public void Delete(string id)
    {
        sampleCollection.Remove(sampleCollection.Where(i => i.Id == Convert.ToInt32(id)) as SampleItem);
    }
 
    [WebInvoke]
    public string InsertSampleItemFromXml(XElement xmlString)
    {
        if (!String.IsNullOrEmpty(xmlString.ToString()))
        {
            return "Got this xml on server -----> " + xmlString.ToString();
        }
        else
        {
            return "Excpetion";
        }
    }
}

You then have to register this in the Global.asax as shown below:

public class Global : HttpApplication {     void Application_Start(object sender, EventArgs e)     {         RegisterRoutes();     }     private void RegisterRoutes()     {         // Edit the base address of Service1 by replacing the "Service1" string below         RouteTable.Routes.Add(new ServiceRoute("RestService", new WebServiceHostFactory(), typeof(RestService)));     }}Once you do this you would have the URL for the service as shown when hosted in IIS:http://localhost/RestVirtualDirectory/RestService/Createhttp://localhost/RestVirtualDirectory/RestService/GetCollectionhttp://localhost/RestVirtualDirectory/RestService/Update