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。

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;

var data = Encoding.ASCII.GetBytes(json);

byte[] postBytes = Encoding.UTF8.GetBytes(json);

使用ASCII代替UFT8

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。

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);

在。net 4.5.1之前,这个选项可以工作:

using (var client = new HttpClient())
{
    client.BaseAddress = new Uri("http://localhost:9000/");
    client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

    var foo = new User
    {
        user = "Foo",
        password = "Baz"
    }

    await client.PostAsJsonAsync("users/add", foo);
}