异步调用wcf 4.5 WCF服务

Question

I want to make sure I have the correct code in place for an asynchronous call to my web service. If someone can please help, I would appreciate it very much.

I am using Visual Studio 2013 with the 4.5.1 framework .

I have the following code in my client application making a call to the service:

public async Task<ActionResult> Read([DataSourceRequest]DataSourceRequest request)
        {    
            try
            {
                YeagerTechWcfService.Status[] status = await db.GetStatusesAsync();

                var serializer = new JavaScriptSerializer();
                var result = new ContentResult();
                serializer.MaxJsonLength = Int32.MaxValue;
                result.Content = serializer.Serialize(status.ToDataSourceResult(request));
                result.ContentType = "application/json";

                return result;
            }

I have the following in my WCF Service Contract for the above method call:

[ServiceContract]
    public interface IYeagerTechWcfService
    {
            [OperationContract]
        Task<List<Status>> GetStatusesAsync();

I have the following in my web service class that implements the interface class for the same method:

public class YeagerTechWcfService : IYeagerTechWcfService
    {
            public async Task<List<Status>> GetStatusesAsync()
        {
            try
            {
                using (YeagerTechEntities DbContext = new YeagerTechEntities())
                {
                    DbContext.Configuration.ProxyCreationEnabled = false;
                    DbContext.Database.Connection.Open();

                    var status = await DbContext.Status.ToListAsync();

                    return status;
                }
            }
            catch (Exception)
            {
                throw;
            }
        }

According to what I was further reading, I would also need the following placed after my OperationContract attribute: * Is this true? *

[OperationContractAttribute(AsyncPattern = true)]
    IAsyncResult BeginGetStatusesAsync(AsyncCallback callback, object asyncState);

    string EndGetStatusesAsync(IAsyncResult result);

Answer 1

No, AsyncPattern is no longer required as of .NET 4.5.

I have a blog post Async WCF Today and Tomorrow that compares the old way of asynchronous WCF ("Today" in the blog post: .NET 4.0) with the new way of asynchronous WCF ("Tomorrow" in the blog post: .NET 4.5).

Answer 2

Your WCF service doesn't have to support asynchronous methods; the client generation ( Add Service Reference ) can generate client-side asynchronous call handling for you.

When adding a Service Reference to your client application, just tick the Generate asynchronous operations checkbox and your proxy class will contain the asynchronous versions of the calls. Easy!