如何使用 .net 4 api 端点从 Request.Content 对象获取原始请求正文

Question

I'm trying to capture the raw request data for accountability and want to pull the request body content out of the Request object.

I've seen suggestions doing a Request.InputStream, but this method is not available on the Request object.

Any idea of how to get a string representation of the Request.Content body?

Answer 1

In your comment on @Kenneth's answer you're saying that ReadAsStringAsync() is returning empty string.

That's because you (or something - like model binder) already read the content, so position of internal stream in Request.Content is on the end.

What you can do is this:

public static string GetRequestBody()
{
    var bodyStream = new StreamReader(HttpContext.Current.Request.InputStream);
    bodyStream.BaseStream.Seek(0, SeekOrigin.Begin);
    var bodyText = bodyStream.ReadToEnd();
    return bodyText;
}

Answer 2

You can get the raw data by calling ReadAsStringAsAsync on the Request.Content property.

string result = await Request.Content.ReadAsStringAsync();

There are various overloads if you want it in a byte or in a stream. Since these are async-methods you need to make sure your controller is async:

public async Task<IHttpActionResult> GetSomething()
{
    var rawMessage = await Request.Content.ReadAsStringAsync();
    // ...
    return Ok();
}

EDIT: if you're receiving an empty string from this method, it means something else has already read it. When it does that, it leaves the pointer at the end. An alternative method of doing this is as follows:

public IHttpActionResult GetSomething()
{
    var reader = new StreamReader(Request.Body);
    reader.BaseStream.Seek(0, SeekOrigin.Begin); 
    var rawMessage = reader.ReadToEnd();

    return Ok();
}

In this case, your endpoint doesn't need to be async (unless you have other async-methods)

Answer 3

For other future users who do not want to make their controllers asynchronous, or cannot access the HttpContext, or are using dotnet core (this answer is the first I found on Google trying to do this), the following worked for me:

[HttpPut("{pathId}/{subPathId}"),
public IActionResult Put(int pathId, int subPathId, [FromBody] myViewModel viewModel)
{

    var body = new StreamReader(Request.Body);
    //The modelbinder has already read the stream and need to reset the stream index
    body.BaseStream.Seek(0, SeekOrigin.Begin); 
    var requestBody = body.ReadToEnd();
    //etc, we use this for an audit trail
}

Answer 4

If you need to both get the raw content from the request, but also need to use a bound model version of it in the controller, you will likely get this exception.

NotSupportedException: Specified method is not supported. 

For example, your controller might look like this, leaving you wondering why the solution above doesn't work for you:

public async Task<IActionResult> Index(WebhookRequest request)
{
    using var reader = new StreamReader(HttpContext.Request.Body);

    // this won't fix your string empty problems
    // because exception will be thrown
    reader.BaseStream.Seek(0, SeekOrigin.Begin); 
    var body = await reader.ReadToEndAsync();

    // Do stuff
}

You'll need to take your model binding out of the method parameters, and manually bind yourself:

public async Task<IActionResult> Index()
{
    using var reader = new StreamReader(HttpContext.Request.Body);

    // You shouldn't need this line anymore.
    // reader.BaseStream.Seek(0, SeekOrigin.Begin);

    // You now have the body string raw
    var body = await reader.ReadToEndAsync();

    // As well as a bound model
    var request = JsonConvert.DeserializeObject<WebhookRequest>(body);
}

It's easy to forget this, and I've solved this issue before in the past, but just now had to relearn the solution. Hopefully my answer here will be a good reminder for myself...

Answer 5

Here's this answer as an extension method:

using System.IO;
using System.Text;

namespace System.Web.Http
{
    public static class ApiControllerExtensions
    {
        public static string GetRequestBody(this ApiController controller)
        {
            using (var stream = new MemoryStream())
            {
                var context = (HttpContextBase)controller.Request.Properties["MS_HttpContext"];
                context.Request.InputStream.Seek(0, SeekOrigin.Begin);
                context.Request.InputStream.CopyTo(stream);
                var requestBody = Encoding.UTF8.GetString(stream.ToArray());
                return requestBody;
            }
        }
    }
}