C#: HTTP POSTする単純な例

gistfile1.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net;
using System.IO;

namespace Example
{
    class Program
    {
        /// <summary>
        /// HTTP POSTする単純な例です。
        /// </summary>
        /// <param name="url">POSTする対象のURL</param>
        /// <param name="parameters">POSTするパラメータ</param>
        /// <returns>POSTに対するレスポンス</returns>
        static WebResponse HttpPost(string url, Dictionary<string, object> parameters)
        {
            // Dictionaryをクエリ文字列のbyte配列に変換します。
            var body = string.Join("&", parameters.Select(pair => {
                return string.Format("{0}={1}",
                    Uri.EscapeDataString(pair.Key),
                    Uri.EscapeDataString(pair.Value.ToString()));
            }).ToArray());
            var bodyBytes = Encoding.ASCII.GetBytes(body);

            // リクエストを生成します。
            var request = (HttpWebRequest)WebRequest.Create(url);
            request.Method = "POST";
            request.ContentType = "application/x-www-form-urlencoded";
            using (var requestStream = request.GetRequestStream()) {
                requestStream.Write(bodyBytes, 0, bodyBytes.Length);
            }

            return request.GetResponse();
        }

        static void Main(string[] args)
        {
            var url = "http://localhost/test/post.php"; // たとえば <?php var_dump($_POST) ?> など
            var parameters = new Dictionary<string, object>() {
                { "foo", 1 },
                { "bar", 2 },
            };

            try {
                var response = HttpPost(url, parameters);
                using (var responseStream = response.GetResponseStream())
                using (var reader = new StreamReader(responseStream)) {
                    Console.WriteLine(reader.ReadToEnd());
                }
            } catch (WebException e) {
                Console.WriteLine(e.ToString());
            }
        }
    }
}