Question

我想向服务器发送http POST请求。此请求包含标头，发布json对象并获取响应。我正在使用此代码：

 var httpWebRequest = (HttpWebRequest)WebRequest.Create(url);   
 httpWebRequest.Accept = "application/json";   
 httpWebRequest.Method = "POST";
 using (var stream = await Task.Factory.FromAsync<Stream>  (httpWebRequest.BeginGetRequestStream, httpWebRequest.EndGetRequestStream, null)){      
     byte[] jsonAsBytes = Encoding.UTF8.GetBytes(jsonString);     
     await stream.WriteAsync(jsonAsBytes, 0, jsonAsBytes.Length);             
 }

我认为我成功发布了我的请求，但我不知道如何获取响应字符串。

Answer 1

请尝试此代码示例。收到的字符串应该是响应。

        String received = null;

        request.Method = "POST";
        request.ContentType = "application/x-www-form-urlencoded";

        byte[] requestBody = Encoding.UTF8.GetBytes(postData);

        // ASYNC: using awaitable wrapper to get request stream
        using (var postStream = await request.GetRequestStreamAsync())
        {
            // Write to the request stream.
            // ASYNC: writing to the POST stream can be slow
            await postStream.WriteAsync(requestBody, 0, requestBody.Length);
        }

        try
        {
            // ASYNC: using awaitable wrapper to get response
            var response = (HttpWebResponse)await request.GetResponseAsync();
            if (response != null)
            {
                var reader = new StreamReader(response.GetResponseStream());
                // ASYNC: using StreamReader's async method to read to end, in case
                // the stream i slarge.
                received = await reader.ReadToEndAsync();
            }
        }
        catch (WebException we)
        {
            var reader = new StreamReader(we.Response.GetResponseStream());
            string responseString = reader.ReadToEnd();
            Debug.WriteLine(responseString);
            return responseString;
        }

        return received;

Answer 2

您可以使用HttpWebResponse

HttpWebResponse myHttpWebResponse = (HttpWebResponse)myHttpWebRequest.GetResponse()

例如：

//Get Response from server
using (HttpWebResponse myHttpWebResponse = (HttpWebResponse)myHttpWebRequest.GetResponse())
{
     StreamReader myStream = new StreamReader(myHttpWebResponse.GetResponseStream());
     string resultJson = myStream.ReadToEnd();
     myStream.Close();
}

然后，您还可以使用序列化API通过以下方式序列化对象中的json：

using System.Runtime.Serialization.Json;

例如：

//Create new instance of JsonObject
MySerializeObject obj = new MySerializeObject();

//Get the byte
byte[] byteArray = Encoding.UTF8.GetBytes(resultJson);

//Create Memorystream from the byteArray
MemoryStream myMemoryStream = new MemoryStream(byteArray);

//Create Json DataContract from serialize object
 DataContractJsonSerializer ser = new DataContractJsonSerializer(typeof(MySerializeObject));

//Read Stream in object
 myMemoryStream.Position = 0;
obj = (MySerializeObject)ser.ReadObject(myMemoryStream);

//Close the stream
myMemoryStream.Close();

Answer 3

我解决了这个问题

        HttpClient Client= new HttpClient();
        Client.DefaultRequestHeaders.Add("accept", "Application/JSON");
          //Add the content body (which is a json object)
        HttpContent content = new StringContent(jsonString);
        //Add the header
        content.Headers.TryAddWithoutValidation("Content-Type", "application/json");
        HttpResponseMessage response = await Client.PostAsync(new Uri(string), content);
      response.EnsureSuccessStatusCode();
      string ch = await response.Content.ReadAsStringAsync();

Answer 4

示例代码：

HttpClient httpClient = new HttpClient();
HttpResponseMessage wcfResponse = await httpClient.PostAsync(new Uri(url), new StringContent(json, Encoding.UTF8, "application/json"));
string result = await wcfResponse.Content.ReadAsStringAsync();
dynamic data = JObject.Parse(result);
var item = data.element;

从http postrequest获得回复

4 个答案: