Accessing the Http Request's Body from HttpActionExecutedContext

Accessing HTTP request bodies in Web API differs from MVC due to stream-based processing. Once the stream is read during the model binding phase, the stream is at the end, and if you try to read it at a later time, you might notice the body is just a blank string.

I encountered this issue while developing an exception filter for logging request bodies. The Request.Content property appeared to contain data, but reading it yielded empty results.

The solution involves repositioning the stream pointer before reading. The following method demonstrates this approach:

private string GetBodyFromRequest(HttpActionExecutedContext context)
{
    string data;
    using (var stream = context.Request.Content.ReadAsStreamAsync().Result)
    {
        if (stream.CanSeek)
        {
            stream.Position = 0;
        }
        data = context.Request.Content.ReadAsStringAsync().Result;
    }
    return data;
}

This function resets the stream position to zero before attempting to read the content, allowing you to retrieve request body data within Web API filter attributes effectively.