C# 如何使用WebRequest发布一些数据并读取响应？

需要让服务器向API发送POST，如何向WebRequest对象添加POST值，如何发送它并获得响应（它将是一个字符串）

我需要发布两个值，有时更多，我在这些示例中看到，它说string postData=“a string to POST”；但是我如何让我发布的东西知道有多个表单值呢

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考虑到信息必须以key1=value1&key2=value2的格式发送，可以在这里找到一个更强大、更灵活的示例：

下面是一个使用HttpWebRequest和HttpWebResponse对象发布到web服务的示例

StringBuilder sb = new StringBuilder();
    string query = "?q=" + latitude + "%2C" + longitude + "&format=xml&key=xxxxxxxxxxxxxxxxxxxxxxxx";
    string weatherservice = "http://api.worldweatheronline.com/free/v1/marine.ashx" + query;
    HttpWebRequest request = (HttpWebRequest)WebRequest.Create(weatherservice);
    request.Referer = "http://www.yourdomain.com";
    HttpWebResponse response = (HttpWebResponse)request.GetResponse();
    Stream stream = response.GetResponseStream();
    StreamReader reader = new StreamReader(stream);
    Char[] readBuffer = new Char[256];
    int count = reader.Read(readBuffer, 0, 256);

    while (count > 0)
    {
        String output = new String(readBuffer, 0, count);
        sb.Append(output);
        count = reader.Read(readBuffer, 0, 256);
    }
    string xml = sb.ToString();

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这是对我有用的。我相信它可以改进，所以请随意提出建议或编辑，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());
}

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下面是从文本文件中读取数据并将其发送给处理程序进行处理的代码，从处理程序接收响应数据并读取数据并将数据存储在string builder类中

 //Get the data from text file that needs to be sent.
                FileStream fileStream = new FileStream(@"G:\Papertest.txt", FileMode.OpenOrCreate, FileAccess.ReadWrite);
                byte[] buffer = new byte[fileStream.Length];
                int count = fileStream.Read(buffer, 0, buffer.Length);

                //This is a handler would recieve the data and process it and sends back response.
                WebRequest myWebRequest = WebRequest.Create(@"http://localhost/Provider/ProcessorHandler.ashx");

                myWebRequest.ContentLength = buffer.Length;
                myWebRequest.ContentType = "application/octet-stream";
                myWebRequest.Method = "POST";
                // get the stream object that holds request stream.
                Stream stream = myWebRequest.GetRequestStream();
                       stream.Write(buffer, 0, buffer.Length);
                       stream.Close();

                //Sends a web request and wait for response.
                try
                {
                    WebResponse webResponse = myWebRequest.GetResponse();
                    //get Stream Data from the response
                    Stream respData = webResponse.GetResponseStream();
                    //read the response from stream.
                    StreamReader streamReader = new StreamReader(respData);
                    string name;
                    StringBuilder str = new StringBuilder();
                    while ((name = streamReader.ReadLine()) != null)
                    {
                        str.Append(name); // Add to stringbuider when response contains multple lines data
                   }
                }
                catch (Exception ex)
                {
                    throw ex;
                }

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示例可以在可能的副本中找到：Wait I see the POST=“”字符串，但如何在该字符串中设置单独的POST表单值？谢谢，所以它就像一个查询字符串，这正是我所需要的，基本上是，所以请注意特殊字符。您需要对键和值进行编码

 //Get the data from text file that needs to be sent.
                FileStream fileStream = new FileStream(@"G:\Papertest.txt", FileMode.OpenOrCreate, FileAccess.ReadWrite);
                byte[] buffer = new byte[fileStream.Length];
                int count = fileStream.Read(buffer, 0, buffer.Length);

                //This is a handler would recieve the data and process it and sends back response.
                WebRequest myWebRequest = WebRequest.Create(@"http://localhost/Provider/ProcessorHandler.ashx");

                myWebRequest.ContentLength = buffer.Length;
                myWebRequest.ContentType = "application/octet-stream";
                myWebRequest.Method = "POST";
                // get the stream object that holds request stream.
                Stream stream = myWebRequest.GetRequestStream();
                       stream.Write(buffer, 0, buffer.Length);
                       stream.Close();

                //Sends a web request and wait for response.
                try
                {
                    WebResponse webResponse = myWebRequest.GetResponse();
                    //get Stream Data from the response
                    Stream respData = webResponse.GetResponseStream();
                    //read the response from stream.
                    StreamReader streamReader = new StreamReader(respData);
                    string name;
                    StringBuilder str = new StringBuilder();
                    while ((name = streamReader.ReadLine()) != null)
                    {
                        str.Append(name); // Add to stringbuider when response contains multple lines data
                   }
                }
                catch (Exception ex)
                {
                    throw ex;
                }