SqlDependency with EntityFramework 6 (async)

Question

I\'m using the EF 6 async querying features, such as

var list = await cx.Clients.Where(c => c.FirstName.Length > 0).ToListAsync();
         


        

Answer 1

I'm not too familiar with SqlDependency, but the below will allow your CallContext to have the correct value at the time ToListAsync is called (When multiple calls are running). Proof of concept here, https://dotnetfiddle.net/F8FnFe

    async Task<List<Client>> GetData()
    {
        using (ClientsContext context = new ClientsContext()) // subclass of DbContext
        {
            SqlDependency.Start(context.Database.Connection.ConnectionString);
            SqlDependency dependency = new SqlDependency();
            dependency.OnChange += (sender, e) =>
            {
                Console.Write(e.ToString());
            };

            Task<List<Client>> task = Task<Task<List<Client>>>.Factory.StartNew(async () =>
            {
                System.Runtime.Remoting.Messaging.CallContext.SetData("MS.SqlDependencyCookie", dependency.Id);
                var list = await context.Clients.Where(c => c.FirstName.Length > 0).ToListAsync();
            }).Unwrap();

            return await task;
        }
    }