Question

My current method of making a call to WCF is the bog standard event, async style (for example)

foo.EventArgs += Foo_EventArgsCompleted
foo.EventArgsAsync(params...)

this works fine, but is hideously slow sometimes and is also cumbersome as you then need another method to deal with the results.

Is there a way to code this closer to the way it’s done on Win8?

private async foo<bool>()
{
  try 
  {
     await foo.EventArgsAsync(params...)
  } 
  catch
  {
     // catch here
  }

  // deal with the code back
  return true;
}

Thanks

Paul

Answer 1

You can write your own *TaskAsync extension methods.

If your proxy has *Begin/*End methods, you can use TaskFactory.FromAsync:

public static Task<int> FooTaskAsync(this FooClient client)
{
  return Task<int>.Factory.FromAsync(client.BeginFoo, client.EndFoo, null);
}

Otherwise, you have to use TaskCompletionSource:

public Task<int> FooTaskAsync(this FooClient client)
{
  var tcs = new TaskCompletionSource<int>();
  client.FooCompleted += (s, e) =>
  {
    if (e.Error != null) tcs.SetException(e.Error);
    else if (e.Cancelled) tcs.SetCanceled();
    else tcs.SetResult(e.Result);
  };
  client.FooAsync();
  return tcs.Task;
}