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

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

其他回答

我最近想出了一个更简单的方法来发布JSON，额外的步骤是从我的应用程序中的模型转换。注意，你必须为你的控制器创建模型[JsonObject]来获取值并进行转换。

要求:

 var model = new MyModel(); 

 using (var client = new HttpClient())
 {
     var uri = new Uri("XXXXXXXXX"); 
     var json = new JavaScriptSerializer().Serialize(model);
     var stringContent = new StringContent(json, Encoding.UTF8, "application/json");
     var response = await client.PutAsync(uri,stringContent).Result;
     // ...
  }

模型:

[JsonObject]
[Serializable]
public class MyModel
{
    public Decimal Value { get; set; }
    public string Project { get; set; }
    public string FilePath { get; set; }
    public string FileName { get; set; }
}

服务器端:

[HttpPut]     
public async Task<HttpResponseMessage> PutApi([FromBody]MyModel model)
{
    // ...
}

2017-01-20 06:46:13

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

一些不同的干净的方法是通过使用HttpClient来实现这一点:

public async Task<HttpResponseMessage> PostResult(string url, ResultObject resultObject)
{
    using (var client = new HttpClient())
    {
        HttpResponseMessage response = new HttpResponseMessage();
        try
        {
            response = await client.PostAsJsonAsync(url, resultObject);
        }
        catch (Exception ex)
        {
            throw ex
        }
        return response;
     }
}

2017-06-01 07:09:13

HttpClient类型是一个比WebClient和HttpWebRequest更新的实现。WebClient和WebRequest都已被标记为过时。[1]

您可以简单地使用以下几行代码。

string myJson = "{'Username': 'myusername','Password':'pass'}";
using (var client = new HttpClient())
{
    var response = await client.PostAsync(
        "http://yourUrl", 
         new StringContent(myJson, Encoding.UTF8, "application/json"));
}

当你不止一次需要你的HttpClient时，建议只创建一个实例并重用它或使用新的HttpClientFactory。[２]

对于FTP，由于HttpClient不支持，我们建议使用第三方库。

@learn.microsoft.com [3]

从dotnet核心3.1开始，你可以使用System.Text.Json中的JsonSerializer来创建你的json字符串。

string myJson = JsonSerializer.Serialize(credentialsObj);

2018-03-13 22:25:22