当来自CreateErrorResponse时，HttpResponseMessage.Content.ReadAsStringAsync不反序列化JSON

Question

if i return from my selfhosted webapi

Request.CreateResponse(HttpStatusCode.OK, "YAY");

everything is fine.. so i can read it like that:

var responseStr = await Client.Content.ReadAsAsync<string>();
and then make something like "MessageBox.Show(responseStr);

if i return

Request.CreateErrorResponse(HttpStatusCode.NotFound, "something went wrong!");

and i read it out the same way or even with(doesn't matter how):

Client.Content.ReadAsStringAsync();

the string is not deserialized and i get an error when trying to parse / read as string.

if i read it as object .. it's fine.. but i can't perform object.ToString(); i get errors..

why? and how to fix it?

Answer 1

I found that there were extra '\\' and '"' in the returned JSON.
So before I serialize back to an object, I needed to remove the extra chars.

eg

string jsonString = httpResponseMessage.Content.ReadAsStringAsync()
                                               .Result
                                               .Replace("\\", "")
                                               .Trim(new char[1] { '"' });

List<VwAisItemMaster> vwAisItemMasterList = JsonConvert.DeserializeObject<List<VwAisItemMaster>>(jsonString);

Answer 2

The better solution is just to fix the issue when creating the response in the webapi method. Note the type in the CreateResponse method.

IList<VwItemMaster> vwItemMasterList = this.itemMastersGetByUpc(unitOfWork, upc);

HttpResponseMessage httpResponseMessage = this.Request.CreateResponse<IList<VwItemMaster>>(HttpStatusCode.OK, vwItemMasterList);

httpResponseMessage.Content.Headers.ContentType = new MediaTypeHeaderValue("application/json");