在asmx webmethod中使用httpclient

Question

is it possible to use httpclient to call a REST service inside an ASMX WebMethod? The httpclient library is async and because asmx does not support async await (TAP), I used .Result to force the call to be sync. However, this time httpclient cannot make the call successfully and I get remote server actively refused connection error. if I run the same piece of code in a win forms application using async await or .Result, it works fine.

is this an issue with ASMX WebMethod?

[WebMethod]
public void Get(){

   //Sample (off the top of my head)
   HttpClient client = new HttpClient();
   //more code
   Task.Run(()=> client.GetDocument()).Result;

}

Thanks

Answer 1

You could inject a module in the pipeline to handle the processing instead of the actual .asmx code. But I would suggest before going to the trouble, just use HttpWebRequest .

Do not do .Result . Do not do Task.Run() in an Asp.Net context.

The module:

public class Proxy : IHttpModule
{
    public void Init(HttpApplication context)
    {
        var wrapper = new EventHandlerTaskAsyncHelper(DoAsyncWork);
        context.AddOnBeginRequestAsync(wrapper.BeginEventHandler, wrapper.EndEventHandler);
    }

    async Task DoAsyncWork(object sender, EventArgs e)
    {
        // await... anything
    }
}