我正在创建一个Web API服务，但是在调用HTTP补丁请求时遇到了一些问题。虽然我知道如何创建它们。如果可以帮助我，我将不胜感激，这是我的代码：

HTTP修补程序代码：

[HttpPatch("{username}")]
        public async Task<ActionResult> Patch(string username, [FromBody] JsonPatchDocument<User> patchDocument)
        { 
            //If no info has been passed, this API call will return badrequest
            if (patchDocument == null)
                return BadRequest();

            var theUser = await connection.GetAUser(username);
            var originalUser = await connection.GetAUser(username);

            if (theUser == null)
                return NotFound();

            //Changes specified in the patchdocument are applied to the user
            patchDocument.ApplyTo(theUser, ModelState);
            //check if the patching has been successful or not
            bool isValid = TryValidateModel(theUser);

            if (!isValid)
                return BadRequest(ModelState);
            else
            {
                bool check = await connection.UpdateUser(originalUser, theUser);
                if (check != true)
                    return BadRequest();
                else
                    return Ok();
            }

        }

与SQL数据库的关联（从前面的代码调用的方法）：

        public async Task<bool> UpdateUser(User originalUser, User patchedUser)
        {
            SqlCommand sqlCommand = new SqlCommand();
            try
            {
                if (originalUser.password != patchedUser.password)
                {
                    //string command = SQL COMMAND
                    SqlParameter param1 = new SqlParameter();
                    param1.ParameterName = "@password";
                    param1.Value = patchedUser.password;
                    SqlParameter param2 = new SqlParameter();
                    param2.ParameterName = "@username";
                    param2.Value = patchedUser.username;

                    sqlCommand.CommandText = command;
                    sqlCommand.Parameters.Add(param1);
                    sqlCommand.Parameters.Add(param2);

                    connection = new DataBaseConnectionService(configuration, sqlCommand);
                    await connection.GetData();
                }
                else
                    return true;
                return true;
            }
            catch (Exception error)
            {
                return false;
            }
        }

我已经在PostMan上对其进行了测试，并且效果很好。问题是我知道如何在PostMan上传递JsonPatchDocument FromBody，但是我不知道如何使用C＃进行操作（我需要使用它来从APP进行调用）。我想寻找有关此问题的答案，但我仅找到有关如何创建API的信息，而没有找到有关如何从C＃调用它的信息。就是这样，如果你需要任何更多信息，我一看到你的要求便会提供，非常感谢你的宝贵时间，希望大家度过愉快的一天。

编辑： 在深入研究此问题之后，我找到了一种可行的方法，但是它返回了405状态代码（“不允许使用方法”）：这是我在C＃应用程序中使用的代码

        public async Task<string> PatchUser(UserModel User_Raw)
        {
            if (client == null)
                InitializeClient();

            try
            {
                //converts the UserModel to JsonPatchDocument<UserModel>
                JsonPatchDocument<UserModel> body = new JsonPatchDocument<UserModel>();
                body.Replace(e = e, User_Raw);

                //Converts the JsonPatchDocument<UserModel> to Json
                var serializedJsonDocument = JsonConvert.SerializeObject(body);
                var stringUser = new StringContent(serializedJsonDocument, UnicodeEncoding.UTF8, "application/json");

                //
                var request = new HttpRequestMessage(new HttpMethod("PATCH"), "Here goes the URL");
                request.Content = stringUser;

                //response stores the Post result to later ensure that it has been successful
                var response = await client.SendAsync(request);
                response.EnsureSuccessStatusCode();

                string HttpResponse = await response.Content.ReadAsStringAsync();
                return HttpResponse;
            }
            catch (HttpRequestException error)
            {
                return null;
            }
            catch (Exception error)
            {
                jsonResult = null;
                return jsonResult;
            }
        }