您如何在C＃/ ASP.NET中读取HttpResponse对象的主体内容？

Question

How do you read the content of an HttpResponse object in C# / ASP.net?

I need to be able to read the body content as a JSON object, modify it, and then write it back to the response output stream. I want to make sure I don't lose what's already in the stream, thus I need to read from it first.

How do I do this?

Answer 1

You can use a Delegating handler

public class ContentHandler : DelegatingHandler
{
    protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
    {
        return base.SendAsync(request, cancellationToken).ContinueWith<HttpResponseMessage>((responseToCompleteTask) =>
        {
            HttpResponseMessage response = responseToCompleteTask.Result;
            var YourContent = response.Content.ReadAsStreamAsync().Result;
            response.Content = new CompressedContent(response.Content, acceptedEncoding);
            return response;
        },
        TaskContinuationOptions.OnlyOnRanToCompletion);
    }
}

Register your handler at WebApiConfig

GlobalConfiguration.Configuration.MessageHandlers.Add(new ContentHandler());

You can edit your reponse content by extending the HttpContent Class. For example to compress content

    public class CompressedContent : HttpContent
{
    private HttpContent originalContent;

    protected override bool TryComputeLength(out long length)
    {
        length = -1;

        return false;
    }

    protected override Task SerializeToStreamAsync(Stream stream, TransportContext context)
    {
        Stream editedStream = null;

        if (encodingType == "gzip")
        {
            editedStream = new GZipStream(stream, CompressionMode.Compress, leaveOpen: true);
        }
        else if (encodingType == "deflate")
        {
            editedStream = new DeflateStream(stream, CompressionMode.Compress, leaveOpen: true);
        }

        return originalContent.CopyToAsync(editedStream).ContinueWith(tsk =>
        {
            if (editedStream != null)
            {
                editedStream.Dispose();
            }
        });
    }
}