C#模拟http 发送post或get请求 ?
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
Post另一实现：
post 调用时传参，如：
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;
}
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Key
var 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.Keys
select string.Format(stringKeyHeader, key, stringDict[key])
into formitem
select 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;
}
单行图片调用以下方法时，如：
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; // =0
while ((bytesRead = fileStream.Read(buffer, 0, buffer.Length)) != 0)
{
memStream.Write(buffer, 0, bytesRead);
}
// 写入字符串的Key
var 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.Keys
select string.Format(stringKeyHeader, key, stringDict[key])
into formitem
select 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;
}
原理简介及简单实现：
WebRequest request = WebRequest.Create("/");//为指定的 URI 方案初始化新的 .WebRequest 实例
request.UseDefaultCredentials = false;//获取或设置一个 System.Boolean 值，该值控制 .CredentialCache.DefaultCredentials
WebResponse response = request.GetResponse();//返回对 Internet 请求的响应。
Stream resStream = response.GetResponseStream();//返回从 Internet 资源返回数据流
StreamReader sr = new StreamReader(resStream, System.Text.Encoding.Default);//实例华一个流的读写器
ContentHtml.Text = sr.ReadToEnd();//这就是百度首页的HTML哦 ,字符串形式的流的其余部分（从当前位置到末尾）。如果当前位置位于流的末尾，则返回空字符串 ("")
resStream.Close();//关闭当前流并释放与之关联的所有资源
sr.Close(); //关闭 System.IO.StreamReader 对象和基础流，并释放与读取器关联的所有系统资源
HttpWebRequest 和 HttpWebResponse 的应用
HttpWebRequestrequest=(HttpWebRequest)WebRequest.Create(addr);
//DownloadstheXMLfilefromthespecifiedserver.
HttpWebResponseresponse=(HttpWebResponse)request.GetResponse();
System.IO.StreamReadersr=newStreamReader(response.GetResponseStream(),System.Text.Encoding.GetEncoding("gb2312"));
Console.Write(sr.ReadToEnd());
sr.Close();
response.Close();
1.获取http地址上的图片
/fooo/archive//06/28/798335.html
HttpWebResponseresp;
HttpWebRequestreq=(HttpWebRequest)HttpWebRequest.Create("/Images/logo_csdn.gif");
req.Timeout=150000;
resp=(HttpWebResponse)req.GetResponse();
System.Drawing.Imageimg;
img=newSystem.Drawing.Bitmap(resp.GetResponseStream());
2.
HttpWebRequest&HttpWebResponse Headers
介绍
这里简要介绍如何使用HttpWebRequest&HttpWebResponse两个对象与HTTP服务器进行直接交互的过程.HttpWebRequest类对WebRequest中定义的属性和方法提供支持,在使用HttpWebRequest对象向HTTP服务器发起请求时请不要使用HttpWebRequest对象的构造函数,而应该使用WebRequest.Create()方法来初始化新的HttpWebRequest对象.如果统一资源标识符方案是"http://"或"https://"时,Create()则返回HttpWebResponse对象.
代码
首先,我们需要创建一个新的HttpWebRequest对象,代码如下:
HttpWebRequest myrequest = (HttpWebRequest)WebRequest.Create(new Uri("urlstring"));
注意:上文中已经提到过不要使用HttpWebRequest的构造函数来创建对象;使用WebRequest.Create()方法初始化HttpWebRequest对象时应该对其进行类型转换.
接下来可以对新初始化的对象进行简单操作,比如可以设置它的标头属性,
下表列出了由属性或方法设置或由系统设置的标头:
注意:HttpWebRequest自动注册.使用以"http://"或"https://"开头的URL之前,不需要调用RegisterPrefix方法来注册
.HttpWebRequest选自:
MSDN:ms-help://MS.MSDNQTR.v80.chs/MS.MSDN.v80/DEVFX.v20.chs/cpref10/html/T_System_Net_HttpWebRequest.htm
在完成对服务器的请求之后,我们需要获取从服务器中返回的信息,正如前面提到过的,使用HttpWebResponse类,具体做法参照如下代码:
HttpWebResponse myresponse = (HttpWebResponse)myrequest.GetResponse();
同样这里我们需要使用HttpWebResponse进行类型转换.到这里,我们已经成功的获得服务器返回的信息,一个myresponse对象,我们可以利用它来获得更多详细的信息,比如从服务器返回的Headers标头,还有其他的有用信息.而在此我们只给您列出如何获得来自服务器响应的Headers标头信息.我们的具体方法是这样的:
#region GetHeaders
public static WebHeaderCollection GetHeaders(Uri uri)
{
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(uri);
// 省略部分代码......
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
// 省略部分代码......
return response.Headers;
}
#endregion
下面就是提供的main()函数:
// The app entry point
public static void Main(string[] args)
{
WebHeaderCollection headers = GetHeaders(new Uri(""));
string[] headkeys = headers.AllKeys;
Console.WriteLine("{0,-30}{1}", "Name", "Value");
Console.WriteLine("--------------------------------");
foreach (string s in headkeys)
{
Console.WriteLine("{0,-30}{1}", s, headers[s]);
}
}
另一种实现方式：
/// <summary>
/// Post data到url
/// </summary>
/// <param name="data">要post的数据</param>
/// <param name="url">目标url</param>
/// <returns>服务器响应</returns>
static string PostDataToUrl(string data, string url)
{
Encoding encoding = Encoding.GetEncoding(sRequestEncoding);
byte[] bytesToPost = encoding.GetBytes(data);
return PostDataToUrl(bytesToPost, url);
}
/// <summary>
/// Post data到url
/// </summary>
/// <param name="data">要post的数据</param>
/// <param name="url">目标url</param>
/// <returns>服务器响应</returns>
static string PostDataToUrl(byte[] data, string url)
{
#region 创建httpWebRequest对象
WebRequest webRequest = WebRequest.Create(url);
HttpWebRequest httpRequest = webRequest as HttpWebRequest;
if (httpRequest == null)
{
throw new ApplicationException(
string.Format("Invalid url string: {0}", url)
);
}
#endregion
#region 填充httpWebRequest的基本信息
httpRequest.UserAgent = sUserAgent;
httpRequest.ContentType = sContentType;
httpRequest.Method = "POST";
#endregion
#region 填充要post的内容
httpRequest.ContentLength = data.Length;
Stream requestStream = httpRequest.GetRequestStream();
requestStream.Write(data, 0, data.Length);
requestStream.Close();
#endregion
#region 发送post请求到服务器并读取服务器返回信息
Stream responseStream;
try
{
responseStream = httpRequest.GetResponse().GetResponseStream();
}
catch (Exception e)
{
// log error
Console.WriteLine(
string.Format("POST操作发生异常：{0}", e.Message)
);
throw e;
}
#endregion
#region 读取服务器返回信息
string stringResponse = string.Empty;
using (StreamReader responseReader =
new StreamReader(responseStream, Encoding.GetEncoding(sResponseEncoding)))
{
stringResponse = responseReader.ReadToEnd();
}
responseStream.Close();
#endregion
return stringResponse;
}
调用时：
string param = string.Format("time={0}&oid={1}&order={2}&name={3}&area={4}&point={5}&amount={6}&return={7}&hash={8}&version={9}", Time, Oid, OrderID, LoginName, Area, Point, Amount, ReturnUrl, HashMoli, Version);
string result = PostDataToUrl(param, PostUrl);
还有一种实现的例子：
使用httpwebrequest Post数据到网站
怎样通过HttpWebRequest 发送 POST 请求到一个网页服务器？例如编写个程序实现自动用户登录，自动提交表单数据到网站等。
假如某个页面有个如下的表单（Form）：
<form name="form1" action="/login.asp" method="post">
<input type="text" name="userid" value="">
<input type="password" name="password" value="">
< /form>
从表单可看到表单有两个表单域，一个是userid另一个是password，所以以POST形式提交的数据应该包含有这两项。
其中POST的数据格式为：
表单域名称1=值1&表单域名称2=值2&表单域名称3=值3……
要注意的是“值”必须是经过HTMLEncode的，即不能包含“<>=&”这些符号。
本例子要提交的数据应该是：
userid=value1&password=value2
用C#写提交程序：
string strId = "guest";
string strPassword= "123456";
ASCIIEncoding encoding=new ASCIIEncoding();
string postData="userid="+strId;
postData += ("&password="+strPassword);
byte[] data = encoding.GetBytes(postData);
// Prepare web request...
HttpWebRequest myRequest =
(HttpWebRequest)WebRequest.Create("/login.asp");
myRequest.Method = "POST";
myRequest.ContentType="application/x-www-form-urlencoded";
myRequest.ContentLength = data.Length;
Stream newStream=myRequest.GetRequestStream();
// Send the data.
newStream.Write(data,0,data.Length);
newStream.Close();
// Get response
HttpWebResponse myResponse=(HttpWebResponse)myRequest.GetResponse();
StreamReader reader = new StreamReader(response.GetResponseStream(),Encoding.Default);
string content = reader.ReadToEnd();
Console.WriteLine(content);
