httpwebrequest客户端请求数据（仿JS里的AJAX写法，使用Lambda表达式）



httpwebrequest客户端请求数据（仿JS里的AJAX写法，使用Lambda表达式）我没有系统的学过C#或者.NET，对一些比较有特点的写法都不太清楚，例如委托和LAMBDA表达式，正好最近一个小程序中使用到，就记录一下。

public delegate void ajaxDeleMethod(string result);

上面的代码是定义一个委托。接下来写一个类似ajax提交请求的部分

public static void Ajax(string method,string url,
Dictionary<string,string> _params,string contentType,CookieContainer cc, 
ajaxDeleMethod  onSucess,ajaxDeleMethod onError)
{
    RequestPackage package = new RequestPackage(url);
    package.Method = method;
    if (_params != null)
    {
        foreach (string key in _params.Keys)
        {
            package.Params.Add(key, _params[key]);
        }
     }
     package.Accept = "*/*";
     package.Cookies = cc;
     try
     {
        HttpWebResponse response = Send2(package);
        if (response.StatusCode == HttpStatusCode.OK)
        {
            using (Stream stream = response.GetResponseStream())
            {
                Stream s = response.GetResponseStream();
                StreamReader sr = new StreamReader(s, Encoding.UTF8);
                onSucess(sr.ReadToEnd());
            }
        }
     }
     catch (Exception ex)
     {
        onError(ex.StackTrace);
     }            
}

使用到了一个类RequestPackage类，这个类就是简单的封闭了一下http头信息，有一个send2用于提交请求并接受返回值，原代码如下：

public static HttpWebResponse Send2(RequestPackage package)
        {
            ArrayList list = new ArrayList();
            HttpWebRequest request = null;
            HttpWebResponse response = null;
            string url = package.RequestURL;
            string method = package.Method.ToString().ToLower();
            if (package.Method.ToLower() == EHttpMethod.Get.ToString().ToLower())//GET
            {
                if (package.Params.Count > 0)
                    url = string.Format("{0}?{1}", url, JoinParams(package.Params));
                request = WebRequest.Create(url) as HttpWebRequest;
                request.AllowAutoRedirect = false;
                request.Accept = package.Accept;
                request.UserAgent = "Mozilla/5.0 (Windows NT 6.3; WOW64; Trident/7.0; MALCJS; rv:11.0) like Gecko";
                request.CookieContainer = package.Cookies;
                request.Referer = package.RefererURL;
                request.Method = method;
            }
            else//POST
            {
                request = WebRequest.Create(url) as HttpWebRequest;
                request.AllowAutoRedirect = false;
                string data = JoinParams(package.Params);
                byte[] b = package.Encoding.GetBytes(data);
                request.ContentType = "application/x-www-form-urlencoded; charset=UTF-8";
                request.Accept = package.Accept;
                request.UserAgent = "Mozilla/5.0 (Windows NT 6.3; WOW64; Trident/7.0; MALCJS; rv:11.0) like Gecko";
                request.CookieContainer = package.Cookies;
                request.Referer = package.RefererURL;
                request.Method = method;
                request.ContentLength = b.Length;
                using (Stream stream = request.GetRequestStream())
                {
                    stream.Write(b, 0, b.Length);
                }
            }
            try
            {
                //获取服务器返回的资源
                response = request.GetResponse() as HttpWebResponse;
                return response;
            }
            catch (WebException wex)
            {
                HttpWebResponse wr = wex.Response as HttpWebResponse;
                return wr;
            }
            catch (Exception ex)
            {
                return response;
            }

        }

ajax的调用方法如下：

Dictionary<string, string> dic = new Dictionary<string, string>();
dic.Add("params", string.Format("{{"num":"{0}"}}", zj));
HttpContext.Ajax("POST","xx/xx/xx.do",dic,"", _cc,
                 dataJson =>
                 {
                    Zjitem data = JsonConvert.DeserializeObject<Zjitem>(dataJson);//先将结果转换为xsddxx对象
                    if (data != null && data.total > 0)
                    {
                        this.gridWL.DataSource = data.rows;
                    }
                 },
                 error => { MessageBox.Show("获取物料明细出错" + error); }
);