如何使用c#发布JSON到服务器?

下面是我使用的代码:

// create a request
HttpWebRequest request = (HttpWebRequest)
WebRequest.Create(url); request.KeepAlive = false;
request.ProtocolVersion = HttpVersion.Version10;
request.Method = "POST";


// turn our request string into a byte stream
byte[] postBytes = Encoding.UTF8.GetBytes(json);

// this is important - make sure you specify type this way
request.ContentType = "application/json; charset=UTF-8";
request.Accept = "application/json";
request.ContentLength = postBytes.Length;
request.CookieContainer = Cookies;
request.UserAgent = currentUserAgent;
Stream requestStream = request.GetRequestStream();

// now send it
requestStream.Write(postBytes, 0, postBytes.Length);
requestStream.Close();

// grab te response and print it out to the console along with the status code
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
string result;
using (StreamReader rdr = new StreamReader(response.GetResponseStream()))
{
    result = rdr.ReadToEnd();
}

return result;

当我运行这个时，我总是得到500个内部服务器错误。

我做错了什么?

当前回答

我最终通过包含.Result在同步模式下调用

HttpResponseMessage response = null;
try
{
    using (var client = new HttpClient())
    {
       response = client.PostAsync(
        "http://localhost:8000/....",
         new StringContent(myJson,Encoding.UTF8,"application/json")).Result;
    if (response.IsSuccessStatusCode)
        {
            MessageBox.Show("OK");              
        }
        else
        {
            MessageBox.Show("NOK");
        }
    }
}
catch (Exception ex)
{
    MessageBox.Show("ERROR");
}

2018-02-27 10:34:45

其他回答

我就是这么做的

//URL
var url = "http://www.myapi.com/";

//Request
using var request = new HttpRequestMessage(HttpMethod.Post, url);

//Headers
request.Headers.Add("Accept", "application/json");
request.Headers.Add("Cache-Control", "no-cache");

//Payload
var payload = JsonConvert.SerializeObject(
    new
    {
        Text = "Hello world"
    });
request.Content = new StringContent(payload, Encoding.UTF8, "application/json");

//Send
var response = await _httpClient.SendAsync(request);

//Handle response
if (response.IsSuccessStatusCode)
    return;

2021-11-15 16:38:48

我发现这是最友好和最简洁的方式来发布读取JSON数据:

var url = @"http://www.myapi.com/";
var request = new Request { Greeting = "Hello world!" };
var json = JsonSerializer.Serialize<Request>(request);
using (WebClient client = new WebClient())
{
    var jsonResponse = client.UploadString(url, json);
    var response = JsonSerializer.Deserialize<Response>(jsonResponse);
}

我正在使用微软的System.Text.Json来序列化和反序列化JSON。NuGet见。

2020-07-31 10:33:46

如果需要异步调用，则使用

var request = HttpWebRequest.Create("http://www.maplegraphservices.com/tokkri/webservices/updateProfile.php?oldEmailID=" + App.currentUser.email) as HttpWebRequest;
            request.Method = "POST";
            request.ContentType = "text/json";
            request.BeginGetRequestStream(new AsyncCallback(GetRequestStreamCallback), request);

private void GetRequestStreamCallback(IAsyncResult asynchronousResult)
    {
        HttpWebRequest request = (HttpWebRequest)asynchronousResult.AsyncState;
        // End the stream request operation

        Stream postStream = request.EndGetRequestStream(asynchronousResult);


        // Create the post data
        string postData = JsonConvert.SerializeObject(edit).ToString();

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


        postStream.Write(byteArray, 0, byteArray.Length);
        postStream.Close();

        //Start the web request
        request.BeginGetResponse(new AsyncCallback(GetResponceStreamCallback), request);
    }

    void GetResponceStreamCallback(IAsyncResult callbackResult)
    {
        HttpWebRequest request = (HttpWebRequest)callbackResult.AsyncState;
        HttpWebResponse response = (HttpWebResponse)request.EndGetResponse(callbackResult);
        using (StreamReader httpWebStreamReader = new StreamReader(response.GetResponseStream()))
        {
            string result = httpWebStreamReader.ReadToEnd();
            stat.Text = result;
        }

    }

2014-01-29 21:54:30

网点网芯方案

首先使用Newtonsoft。Json，然后写一个这样的方法:

    public static string? LoginToken()
    {
        var httpWebRequest = (HttpWebRequest)WebRequest.Create("http://url");
        httpWebRequest.ContentType = "application/json";
        httpWebRequest.Method = "POST";

        using (var streamWriter = new StreamWriter(httpWebRequest.GetRequestStream()))
        {
           //  write your json content here
            string json = JsonConvert.SerializeObject(new
            {
                userName = ApiOptions.Username,
                password = ApiOptions.Password
            }
            );


            streamWriter.Write(json);
        }

        var httpResponse = (HttpWebResponse)httpWebRequest.GetResponse();
        using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
        {
            var result = streamReader.ReadToEnd();
            return result;
        }

    }

这个方法返回字符串。如果你想将字符串结果反序列化为JSON，只需在方法的末尾添加这一行:

var result = streamReader.ReadToEnd();               
var json_result = JsonConvert.DeserializeObject<LoginTokenResponse>(result); // + add this code

哪个LoginTokenResponse是您要反序列化字符串结果的自定义类

2021-12-02 06:20:05

admar的解决方案可以通过利用JavaScriptSerializer的Serialize方法来提供对象到JSON的隐式转换来改进。

此外，还可以利用using语句的默认功能，以避免显式调用Flush和Close。

var httpWebRequest = (HttpWebRequest)WebRequest.Create("http://url");
httpWebRequest.ContentType = "application/json";
httpWebRequest.Method = "POST";

using (var streamWriter = new StreamWriter(httpWebRequest.GetRequestStream()))
{
    string json = new JavaScriptSerializer().Serialize(new
                {
                    user = "Foo",
                    password = "Baz"
                });

    streamWriter.Write(json);
}

var httpResponse = (HttpWebResponse)httpWebRequest.GetResponse();
using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
{
    var result = streamReader.ReadToEnd();
}

2013-05-04 23:56:06

如何使用c#发布JSON到服务器?

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