webclient类学习

(HttpWebRequest模拟请求登录):当一些硬件设备接口 或需要调用其他地方的接口时，模拟请求登录获取接口的数据就很有必要。

webclient类:只想从特定的URI请求文件，则使用WebClient;

1.创建带Cookie的webclient：

    /// <summary>
    /// 带 Cookie 的 WebClient
    /// </summary>
    public class CookieWebClient : WebClient
    {
        // Cookie 容器
        public CookieContainer Cookies;  

        /// <summary>
        /// 创建一个新的 CookieWebClient 实例。
        /// </summary>
        public CookieWebClient()
        {
            this.Cookies = new CookieContainer();
        }  

        protected override WebRequest GetWebRequest(Uri address)
        {
            WebRequest request = base.GetWebRequest(address);
            if (request is HttpWebRequest)
            {
                HttpWebRequest httpRequest = request as HttpWebRequest;
                httpRequest.CookieContainer = Cookies;
            }
            return request;
        }
    }  

2.http方法（Get、POST）:

public  CookieContainer cookies;
        internal string HttpGet(string Url)
        {
            string result = "";
            using (var client = new CookieWebClient())
            {
                client.Encoding = Encoding.UTF8;
                client.Headers[HttpRequestHeader.ContentType] = "application/x-www-form-urlencoded,charset=UTF-8";
                client.Cookie = cookies;
                byte[] data = client.DownloadData(Url);
                result = Encoding.UTF8.GetString(data);
            }
            return result;
        }
        internal string HttpPost(string Url, string postDataStr)
        {
            string result = "";
            using (var client = new CookieWebClient())
            {
                client.Encoding = Encoding.UTF8;
                client.Headers[HttpRequestHeader.ContentType] = "application/x-www-form-urlencoded; charset=UTF-8";
                byte[] post = Encoding.UTF8.GetBytes(postDataStr);
                byte[] data = client.UploadData(Url,post);
                result = Encoding.UTF8.GetString(data);
                cookies = client.Cookie;
            }
            return result;
        }

3. controller

 [HttpGet]
        public string Getinfo(string name, string pwd)
        {
            string hg = "";
            string url = "http://111.38.56.130:8084/LoginHandler.ashx?time=" + DateTime.Now;
            string loginp = "action=Login&flag=1&name={0}&pwd={1}&isRemember=false";
            string urlget = "http://111.38.56.130:8084/Company/IndexHandler.ashx?time={0}&action=deviceShowData&greenHouseSerialNum=00000F003G001";
            string param = string.Format(loginp, name, pwd);
            exta.http h = new exta.http();
            string r = h.HttpPost(url, param);
            if (r.Equals(""))
            {
                hg = h.HttpGet(string.Format(urlget, DateTime.Now));
            }
            return hg;
        }