如何使用WebRequest来发布一些数据并读取响应？

Question

需要让服务器对API进行POST,如何将POST值添加到WebRequest对象以及如何发送它并获得响应(它将是一个字符串)？

我需要POST两个值,有时候更多,我在这些例子中看到它表示字符串postData ="要发布的字符串"; 但是我怎么让我发布的东西知道有多个表单值？

Answer 1

来自MSDN

// Create a request using a URL that can receive a post. 
WebRequest request = WebRequest.Create ("http://contoso.com/PostAccepter.aspx ");
// Set the Method property of the request to POST.
request.Method = "POST";
// Create POST data and convert it to a byte array.
string postData = "This is a test that posts this string to a Web server.";
byte[] byteArray = Encoding.UTF8.GetBytes (postData);
// Set the ContentType property of the WebRequest.
request.ContentType = "application/x-www-form-urlencoded";
// Set the ContentLength property of the WebRequest.
request.ContentLength = byteArray.Length;
// Get the request stream.
Stream dataStream = request.GetRequestStream ();
// Write the data to the request stream.
dataStream.Write (byteArray, 0, byteArray.Length);
// Close the Stream object.
dataStream.Close ();
// Get the response.
WebResponse response = request.GetResponse ();
// Display the status.
Console.WriteLine (((HttpWebResponse)response).StatusDescription);
// Get the stream containing content returned by the server.
dataStream = response.GetResponseStream ();
// Open the stream using a StreamReader for easy access.
StreamReader reader = new StreamReader (dataStream);
// Read the content.
string responseFromServer = reader.ReadToEnd ();
// Display the content.
Console.WriteLine (responseFromServer);
// Clean up the streams.
reader.Close ();
dataStream.Close ();
response.Close ();

请注意,必须以key1 = value1&key2 = value2格式发送信息

Answer 2

这对我有用.我确信它可以改进,所以随时提出建议或编辑以使其更好.

const string WEBSERVICE_URL = "http://localhost/projectname/ServiceName.svc/ServiceMethod";
//This string is untested, but I think it's ok.
string jsonData = "{ \"key1\" : \"value1\", \"key2\":\"value2\"  }"; 
try
{       
    var webRequest = System.Net.WebRequest.Create(WEBSERVICE_URL);
    if (webRequest != null)
    {
        webRequest.Method = "POST";
        webRequest.Timeout = 20000;
        webRequest.ContentType = "application/json";

    using (System.IO.Stream s = webRequest.GetRequestStream())
    {
        using (System.IO.StreamWriter sw = new System.IO.StreamWriter(s))
            sw.Write(jsonData);
    }

    using (System.IO.Stream s = webRequest.GetResponse().GetResponseStream())
    {
        using (System.IO.StreamReader sr = new System.IO.StreamReader(s))
        {
            var jsonResponse = sr.ReadToEnd();
            System.Diagnostics.Debug.WriteLine(String.Format("Response: {0}", jsonResponse));
        }
    }
}
}
catch (Exception ex)
{
    System.Diagnostics.Debug.WriteLine(ex.ToString());
}