asp.net-mvc - 如何在 MVC 4 Web Api 中接收 XmlDocument？

Question

我将 XmlDocument 发布到 ApiController(来自 Windows 服务，服务工作正常，发布正确，我在 wcf web api 中使用它)，但 xml 始终为空，我做错了什么？
我可以发布一些类(class)，例如教程，或者获取任何数据，一切都会好起来的，但我无法发布 XmlDocument。

public class XmlController : ApiController
{
    public void PostXml(XmlDocument xml)
    {
       // code
    }
}

Answer 1

我遵循@Rhot 给出的解决方案，但不知何故它不起作用，所以我编辑如下，这对我有用:

public class XmlMediaTypeFormatter : MediaTypeFormatter
    {
        public XmlMediaTypeFormatter()
        {
            SupportedMediaTypes.Add(new MediaTypeHeaderValue("application/xml"));
        }

        public override bool CanReadType(Type type)
        {
            return type == typeof(XDocument);
        }

        public override bool CanWriteType(Type type)
        {
            return type == typeof(XDocument);
        }

        public override Task<object> ReadFromStreamAsync(Type type, Stream stream, HttpContent content, IFormatterLogger formatterLogger)
        {
            var reader = new StreamReader(stream);
            string value = reader.ReadToEnd();            

            var tcs = new TaskCompletionSource<object>();
            try
            {
                var xmlDoc = XDocument.Parse(value);
                tcs.SetResult(xmlDoc);
            }
            catch (Exception ex)
            {
                //disable the exception and create custome error
                //tcs.SetException(ex);
                var xml = new XDocument(
                    new XElement("Error",
                        new XElement("Message", "An error has occurred."),
                        new XElement("ExceptionMessage", ex.Message)
                ));

                tcs.SetResult(xml);
            }

            return tcs.Task;
        }

        public override Task WriteToStreamAsync(Type type, object value, Stream stream, HttpContent content, TransportContext transportContext)
        {
            var writer = new StreamWriter(stream);
            writer.Write(((XDocument)value).ToString());
            writer.Flush();

            var tcs = new TaskCompletionSource<object>();
            tcs.SetResult(null);
            return tcs.Task;
        }              
    }

注册到 global.asax:

GlobalConfiguration.Configuration.Formatters.Insert(0, new XmlMediaTypeFormatter());

在我的 WebAPI Controller 下方:

public HttpResponseMessage Post(XDocument xml)
        {            
            return Request.CreateResponse(HttpStatusCode.OK, xml);
        }