没有MediaTypeFormatter可用于在asp.net web api中读取"Advertisement"类型的对象

Question

我有一个名为广告的类:

 public class Advertisement
{
    public string Title { get; set; }
    public string Desc { get; set; }
}

在我的控制器中:

public class OrderController : ApiController
{
    public UserManager<IdentityUser> UserManager { get; private set; }

    // Post api/Order/Test

    [Route("Test")]
    public IHttpActionResult Test(Advertisement advertisement)
    {
        var currentUser = User.Identity.GetUserId();
        Task<IdentityUser> user = UserManager.FindByIdAsync(currentUser);

      return Ok(User.Identity.GetUserId());
    }

但是当我用Postman测试它时我遇到了这个错误,

 "Message": "The request contains an entity body but no Content-Type header. The inferred media type 'application/octet-stream' is not supported for this resource.",
"ExceptionMessage": "No MediaTypeFormatter is available to read an object of type 'Advertisement' from content with media type 'application/octet-stream'.",
"ExceptionType": "System.Net.Http.UnsupportedMediaTypeException",
"StackTrace": "   at System.Net.Http.HttpContentExtensions.ReadAsAsync[T](HttpContent content, Type type, IEnumerable`1 formatters, IFormatterLogger formatterLogger, CancellationToken cancellationToken)\r\n   at System.Net.Http.HttpContentExtensions.ReadAsAsync(HttpContent content, Type type, IEnumerable`1 formatters, IFormatterLogger formatterLogger, CancellationToken cancellationToken)\r\n   at System.Web.Http.ModelBinding.FormatterParameterBinding.ReadContentAsync(HttpRequestMessage request, Type type, IEnumerable`1 formatters, IFormatterLogger formatterLogger, CancellationToken cancellationToken)"

有谁能够帮我？

Answer 1

在你WebApiConfig.cs添加这个寄存器里面

config.Formatters.JsonFormatter.SupportedMediaTypes.Add(new MediaTypeHeaderValue("application/octet-stream"));

Answer 2

"ExceptionMessage": "没有 MediaTypeFormatter 可用于从媒体类型为“application/octet-stream”的内容中读取类型为“广告”的对象。",

这意味着您的应用程序无法读取八位字节流内容类型 - 这是请求提供的内容。这是我对 Web API 的一大不满。不过，有一种方法可以解决这个问题。简单的方法是将 Content-type 修改为易于阅读的“application/json”或“application/xml”。更困难的方法是提供您自己的 MediaTypeFormatter。