ASP.NET MVC Controller cannot return HttpResponseMessage correctly with streamed content

问题

Just as the title says I am not getting the MVC Controller to return HttpResponseMessage correctly.

    [HttpGet]
    [AllowAnonymous]
    public HttpResponseMessage GetDataAsJsonStream()
    {
        object returnObj = new
        {
            Name = "Alice",
            Age = 23,
            Pets = new List<string> { "Fido", "Polly", "Spot" }
        };

        var response = Request.CreateResponse(HttpStatusCode.OK);
        var stream = new MemoryStream().SerializeJson(returnObj);
        stream.Position = 0;
        response.Content = new StreamContent(stream);
        response.Content.Headers.ContentType = new MediaTypeHeaderValue("application/json");

        return response;
    }

This is what I got using MVC Controller:

It works fine when using WebApi ApiController

Correct me if I'm wrong I think the problem is MVC is serializing HttpResponseMessage instead of returning it.

By the way I am using MVC 5.

Thanks in advance.

EDIT I would like to have the flexibility to write to the response stream directly when returning large datasets.

回答1:

Perhaps try returning an ActionResult from your MVC method instead.

public ActionResult GetDataAsJsonStream() {}

In order to return a stream, you'll likely have to use FileStreamResult. What would be even easier is just returning a JsonResult.

public ActionResult GetDataAsJson()
{
    object returnObj = new
    {
        Name = "Alice",
        Age = 23,
        Pets = new List<string> { "Fido", "Polly", "Spot" }
    };

    return Json(returnObj, JsonRequestBehavior.AllowGet);
}

This is pseudo code but the concept should be sound.

回答2:

Thanks to Phil I got it to work by having the MVC controller return FileStreamResult.

Here is the code

    public ActionResult GetDataAsJsonStream()
    {
        object returnObj = new
        {
            Name = "Alice",
            Age = 23,
            Pets = new List<string> { "Fido", "Polly", "Spot" }
        };

        var stream = new MemoryStream().SerializeJson(returnObj);
        stream.Position = 0;

        return File(stream, "application/json");
    }

UPDATE

A better way to do this is to write directly to the response stream without creating a memory stream

    public ActionResult GetJsonStreamWrittenToResponseStream()
    {
        object returnObj = new
        {
            Name = "Alice",
            Age = 23,
            Pets = new List<string> { "Fido", "Polly", "Spot" }
        };

        Response.ContentType = "application/json";
        Response.OutputStream.SerializeJson(returnObj);

        return new EmptyResult();
    }

来源：https://stackoverflow.com/questions/37964330/asp-net-mvc-controller-cannot-return-httpresponsemessage-correctly-with-streamed