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Editorial Team
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Asked: 2026-05-12T17:06:12+00:00

I am trying to design an Picture Upload feature into a web site. I

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I am trying to design an Picture Upload feature into a web site.
I am using ASP.NET 3.5, C#, and WCF.

I have been asked to accomplish the following:

1) Make the Uploader a Web Service
2) Return progress updates to the user as files are uploaded.
3) Log other relevant user-selected options in the database.

So, I have started off by creating a WCF web client with the
below service contract:

IService.UploadPictures(HttpRequest request);

private UploadServiceClient upload;

protected void Page_Load(object sender, EventArgs e)
{

      upload = new UploadServiceClient();
      upload.UploadPictures(Request.Files);

}

When I compile, I get the below error:

Type ‘System.Web.HttpRequest’ cannot
be serialized. Consider marking it
with the DataContractAttribute, and
marking all of its members you want
serialized with the
DataMemberAttribute attribute.

So, I went back into my service contract and
changed [OperationContract] to [DataContract]
but the change produced the same error.

Can somebody kindly tell me what I am doing wrong
and provide examples as to how to best move forward?

Thanks for your time.

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1 Answer

  1. Editorial Team

    You cannot use something like a HttpRequest as a WCF parameter. The error messages says it all – the HttpRequest is not serializable, and in order to work with WCF, types have to be serializable.

    Also, you need to remember: you’re not just passing an object instance to a method here – what you’re really doing is having the WCF runtime serialize your request (the method name to call plus all the parameters passed in) into a message (think: e-mail or xml file), sending it to the server, deserialising there and building up a new copy of the given datatype (as defined in your DataContract), and doing something with it.

    Your WCF service could well be self-hosted, e.g. running in a NT Service or console app – no HttpRequest available in those circumstances!

    You need to definitely rearchitect your solution – you need to either check into WCF streaming to upload files to WCF (google for it – you’ll find plenty of hits) or you’ll need to find another way to pass the relevant info (e.g. list of filenames) to the WCF service without use of a HttpRequest object.

    Marc

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