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c#asp.netwebrequest

How to use WebRequest to POST some data and read response?


Need to have the server make a POST to an API, how do I add POST values to a WebRequest object and how do I send it and get the response (it will be a string) out?

I need to POST TWO values, and sometimes more, I see in these examples where it says string postData = "a string to post"; but how do I let the thing I am POSTing to know that there is multiple form values?


Solution

  • From 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 ();
    

    Take into account that the information must be sent in the format key1=value1&key2=value2