一、基本示例
private string HttpPost(string Url, string postDataStr){HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url);request.Method = "POST";request.ContentType = "application/x-www-form-urlencoded";request.ContentLength = Encoding.UTF8.GetByteCount(postDataStr);request.CookieContainer = cookie;Stream myRequestStream = request.GetRequestStream();StreamWriter myStreamWriter = new StreamWriter(myRequestStream, Encoding.GetEncoding("gb2312"));myStreamWriter.Write(postDataStr);myStreamWriter.Close();HttpWebResponse response = (HttpWebResponse)request.GetResponse();response.Cookies = cookie.GetCookies(response.ResponseUri);Stream myResponseStream = response.GetResponseStream();StreamReader myStreamReader = new StreamReader(myResponseStream, Encoding.GetEncoding("utf-8"));string retString = myStreamReader.ReadToEnd();myStreamReader.Close();myResponseStream.Close();return retString;}public string HttpGet(string Url, string postDataStr){HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url + (postDataStr == "" ? "" : "?") + postDataStr);request.Method = "GET";request.ContentType = "text/html;charset=UTF-8";HttpWebResponse response = (HttpWebResponse)request.GetResponse();Stream myResponseStream = response.GetResponseStream();StreamReader myStreamReader = new StreamReader(myResponseStream, Encoding.GetEncoding("utf-8"));string retString = myStreamReader.ReadToEnd();myStreamReader.Close();myResponseStream.Close();return retString;}
在post的时候有时也用的到cookie，像登录163发邮件时候就需要发送cookie，所以在外部一个cookie属性随时保存 CookieContainer cookie = new CookieContainer();
注意：有时候请求会重定向，但我们就需要从重定向url获取东西，像QQ登录成功后获取sid，但上面的会自动根据重定向地址跳转。我们可以用:
request.AllowAutoRedirect = false;设置重定向禁用，你就可以从headers的Location属性中获取重定向地址。
二、post 调用时传参
string url = "/";
string result = string.Empty;
string param = string.Format("WechatOpenID={0}&Content={1}", webchatOpenID, content);
result = HttpPostData(url, param);
public string HttpPostData(string url, string param){var result = string.Empty;//注意提交的编码 这边是需要改变的 这边默认的是Default：系统当前编码byte[] postData = Encoding.UTF8.GetBytes(param);// 设置提交的相关参数 HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;Encoding myEncoding = Encoding.UTF8;request.Method = "POST";request.KeepAlive = false;request.AllowAutoRedirect = true;request.ContentType = "application/x-www-form-urlencoded";request.UserAgent = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 2.0.50727; .NET CLR 3.0.04506.648; .NET CLR 3.5.21022; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729)";request.ContentLength = postData.Length;// 提交请求数据 System.IO.Stream outputStream = request.GetRequestStream();outputStream.Write(postData, 0, postData.Length);outputStream.Close();HttpWebResponse response;Stream responseStream;StreamReader reader;string srcString;response = request.GetResponse() as HttpWebResponse;responseStream = response.GetResponseStream();reader = new System.IO.StreamReader(responseStream, Encoding.GetEncoding("UTF-8"));srcString = reader.ReadToEnd();result = srcString; //返回值赋值reader.Close();return result;}
三、Post传输图片等时的代码示例
Post多张图片和其他参数时，用此方法进行调用，调用方法如：
//imgDic是图片接收名称如media,图片本地完整路径或网络完整路径的键值对的集合
imgDesc是图片信息参数及其他参数的集合，图片信息如media1,media2,media3等，这个图片接收名字是由接收方确定的
注意：
FileStream只能用于本地完整路径，如C/xx.jpg等，如果是网路图片则无法使用它。
推荐使用
WebClient wc = new WebClient();
byte[] buffer = wc.DownloadData(filePath);
memStream.Write(buffer, 0, buffer.Length);
这种方式，这个类无论是网路图片还是本地图片都可以使用，但路径中要用/，而不是\，否则会出现不支持URI的错误。
if (openIDList != null && openIDList.Any() && imgDesc != null)
{
Dictionary<string, string> imgDic = new Dictionary<string, string>();
foreach (var item in imgDesc)
{
imgDic.Add(item.name, item.path);
}
NameValueCollection col = new NameValueCollection();
col.Add("imgDesc", Newtonsoft.Json.JsonConvert.SerializeObject(imgDesc));
col.Add("open_ids", string.Join(",", openIDList));
result = HttpPostData(url, 60000, imgDic, col);
}
private static string HttpPostData(string url, int timeOut, Dictionary<string, string> imgDic, NameValueCollection stringDict){LogEntry entry = new LogEntry("发送图片开始-HttpPostData -- " + stringDict["open_ids"], 1);LogStub.Log(entry);var firstImg = imgDic.FirstOrDefault();string fileKeyName = firstImg.Key;string filePath = firstImg.Value;string responseContent;var memStream = new MemoryStream();var webRequest = (HttpWebRequest)WebRequest.Create(url);// 边界符var boundary = "---------------" + DateTime.Now.Ticks.ToString("x");// 边界符var beginBoundary = Encoding.ASCII.GetBytes("--" + boundary + "\r\n");//var fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read);// 最后的结束符var endBoundary = Encoding.ASCII.GetBytes("--" + boundary + "--\r\n");// 设置属性webRequest.Method = "POST";webRequest.Timeout = timeOut;webRequest.ContentType = "multipart/form-data; boundary=" + boundary;// 写入文件const string filePartHeader ="Content-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"\r\n" +"Content-Type: application/octet-stream\r\n\r\n";var header = string.Format(filePartHeader, fileKeyName, filePath);var headerbytes = Encoding.UTF8.GetBytes(header);memStream.Write(beginBoundary, 0, beginBoundary.Length);memStream.Write(headerbytes, 0, headerbytes.Length);//var buffer = new byte[1024];//int bytesRead; // =0//while ((bytesRead = fileStream.Read(buffer, 0, buffer.Length)) != 0)//{// memStream.Write(buffer, 0, bytesRead);//}WebClient wc = new WebClient();byte[] buffer = wc.DownloadData(filePath);memStream.Write(buffer, 0, buffer.Length);//第二章图片//memStream.Write(beginBoundary, 0, beginBoundary.Length);//var aaa = Encoding.ASCII.GetBytes("\r\n--" + boundary + "\r\n");//memStream.Write(aaa, 0, aaa.Length);string imgName = string.Empty;string imgPath = string.Empty;foreach (var img in imgDic.Where(p => p.Key != fileKeyName)){imgName = img.Key;imgPath = img.Value;string nxetFileFormat = "\r\n--" + boundary + "\r\n" + filePartHeader;header = string.Format(nxetFileFormat, imgName, imgPath);headerbytes = Encoding.UTF8.GetBytes(header);memStream.Write(headerbytes, 0, headerbytes.Length);//fileStream = new FileStream(imgPath, FileMode.Open, FileAccess.Read);//while ((bytesRead = fileStream.Read(buffer, 0, buffer.Length)) != 0)//{// memStream.Write(buffer, 0, bytesRead);//}buffer = wc.DownloadData(imgPath);memStream.Write(buffer, 0, buffer.Length);}// 写入字符串的Keyvar stringKeyHeader = "\r\n--" + boundary +"\r\nContent-Disposition: form-data; name=\"{0}\"" +"\r\n\r\n{1}\r\n";foreach (byte[] formitembytes in from string key in stringDict.Keysselect string.Format(stringKeyHeader, key, stringDict[key])into formitemselect Encoding.UTF8.GetBytes(formitem)){memStream.Write(formitembytes, 0, formitembytes.Length);}// 写入最后的结束边界符memStream.Write(endBoundary, 0, endBoundary.Length);webRequest.ContentLength = memStream.Length;var requestStream = webRequest.GetRequestStream();memStream.Position = 0;var tempBuffer = new byte[memStream.Length];memStream.Read(tempBuffer, 0, tempBuffer.Length);memStream.Close();requestStream.Write(tempBuffer, 0, tempBuffer.Length);requestStream.Close();var httpWebResponse = (HttpWebResponse)webRequest.GetResponse();using (var httpStreamReader = new StreamReader(httpWebResponse.GetResponseStream(),Encoding.GetEncoding("utf-8"))){responseContent = httpStreamReader.ReadToEnd();}fileStream.Close();httpWebResponse.Close();webRequest.Abort();entry = new LogEntry("发送图片结束-HttpPostData -- " + responseContent, 1);LogStub.Log(entry);return responseContent;}
四、单张图片调用
NameValueCollection col = new NameValueCollection();
//col.Add("media", filePath);
col.Add("title", title);
col.Add("content", content);
col.Add("open_ids", string.Join(",", openIDList));
result = HttpPostData(url, 60000, "media", filePath, col);
filePath是客户端的图片完整路径，
media是服务端接受图片的参数，这个要看接收端接收图片的参数名，注意此方法是单张图片的post调用
private static string HttpPostData(string url, int timeOut, string fileKeyName,string filePath, NameValueCollection stringDict){string responseContent;var memStream = new MemoryStream();var webRequest = (HttpWebRequest)WebRequest.Create(url);// 边界符var boundary = "---------------" + DateTime.Now.Ticks.ToString("x");// 边界符var beginBoundary = Encoding.ASCII.GetBytes("--" + boundary + "\r\n");var fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read);// 最后的结束符var endBoundary = Encoding.ASCII.GetBytes("--" + boundary + "--\r\n");// 设置属性webRequest.Method = "POST";webRequest.Timeout = timeOut;webRequest.ContentType = "multipart/form-data; boundary=" + boundary;// 写入文件const string filePartHeader ="Content-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"\r\n" +"Content-Type: application/octet-stream\r\n\r\n";var header = string.Format(filePartHeader, fileKeyName, filePath);var headerbytes = Encoding.UTF8.GetBytes(header);memStream.Write(beginBoundary, 0, beginBoundary.Length);memStream.Write(headerbytes, 0, headerbytes.Length);var buffer = new byte[1024];int bytesRead; // =0while ((bytesRead = fileStream.Read(buffer, 0, buffer.Length)) != 0){memStream.Write(buffer, 0, bytesRead);}// 写入字符串的Keyvar stringKeyHeader = "\r\n--" + boundary +"\r\nContent-Disposition: form-data; name=\"{0}\"" +"\r\n\r\n{1}\r\n";foreach (byte[] formitembytes in from string key in stringDict.Keysselect string.Format(stringKeyHeader, key, stringDict[key])into formitemselect Encoding.UTF8.GetBytes(formitem)){memStream.Write(formitembytes, 0, formitembytes.Length);}// 写入最后的结束边界符memStream.Write(endBoundary, 0, endBoundary.Length);webRequest.ContentLength = memStream.Length;var requestStream = webRequest.GetRequestStream();memStream.Position = 0;var tempBuffer = new byte[memStream.Length];memStream.Read(tempBuffer, 0, tempBuffer.Length);memStream.Close();requestStream.Write(tempBuffer, 0, tempBuffer.Length);requestStream.Close();var httpWebResponse = (HttpWebResponse)webRequest.GetResponse();using (var httpStreamReader = new StreamReader(httpWebResponse.GetResponseStream(),Encoding.GetEncoding("utf-8"))){responseContent = httpStreamReader.ReadToEnd();}fileStream.Close();httpWebResponse.Close();webRequest.Abort();return responseContent;}
