.net 核心与 httpclient 请求删除和正文

Question

我需要在调用 HttpMethod:DELETE 时通过正文传递一个参数

我得到了回应：方法不允许（403）

var request = new HttpRequestMessage
{
    Method = HttpMethod.Delete,
    RequestUri = new Uri($"{_iOptions.Server}{_iOptions.Method.DeleteAllKeys}")
};

request.Content = new ByteArrayContent(Encoding.UTF8.GetBytes("{ \"umcn\": " + umcn + " }"));
request.Content.Headers.ContentType = new MediaTypeHeaderValue("application/json");

var responseMessage = await _httpClient.SendAsync(request).ConfigureAwait(false); 
// here in responseMessage error code is: System.Net.HttpStatusCode.MethodNotAllowed

responseMessage.EnsureSuccessStatusCode();

GeneralResponseModel response = await responseMessage.Content.ReadAsAsync<GeneralResponseModel>();

if (response.Code == (int)System.Net.HttpStatusCode.OK)
{
    response.Success = true;
    return response;
}
else
{
    response.Success = false;
    return response;
};

umcn 属性是表示一个字符串值。