CODEWITHSUNDEEP
silverlightweb-servicesasynchronous
olegz
olegz

Reputation: 1222

Asynchronous Begin/End pattern for webservices in silverlight project

I found that the proxy generated with SlSvcUtil.exe (or by adding reference to Web References) only supports Event based async model which is absolutely inappropriate from design point of view (events were 2nd class citizens from the first days).

I'm going to implement F#'s async builder approach and I found "old style" Begin/End are much easier to be generalized. I notices SlSvcUtil.exe generates Begin/End methods pair but marks them both with private keyword?

A couple options on top of my head are:

Any ideas?

Say someone created a remote service with one method:

public interface CompressService
{
    public byte[] Compress(byte[] inData);
}

After SlSvcUtil I got:

public class CompressServiceSoapClient: ClientBase<CompressServiceSoap...
{
    private BeginOperationDelegate onBeginCompressDelegate;
    private EndOperationDelegate onEndCompressDelegate;
    public event System.EventHandler<CompressCompletedEventArgs> CompressCompleted;
    public void CompressAsync(byte[] inData, object userState);
}

While in fact I need:

public class CompressServiceSoapClient: ClientBase<CompressServiceSoap...
{
    public IAsyncResult BeginCompress(byte[] inData, System.AsyncCallback callback, object asyncState);
    public byte[] EndCompress(IAsyncResult result);
}

Answer

The solution is to declare contract interface with async methods and do not use generated code inherited from ClientBase<>. The article http://msdn.microsoft.com/en-us/library/dd744834(v=vs.95).aspx describes this in more details.

Upvotes: 1

Views: 884

Answers (1)

Jeremy Likness
Jeremy Likness

Reputation: 7521

You can access the begin/end methods by using the channel factory for the end point.

Basically just create a new ChannelFactory and pass in a binding and end point. You can use the host source to dynamically update the end point so it's not hard-coded. The resulting instance will expose the begin/end methods for you.

Upvotes: 2

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