一、HttpWebRequest简介
1. HttpWebRequest和HttpWebResponse对比
1、HttpWebRequest和HttpWebResponse类是用于发送和接收HTTP数据的最好选择。 2、命名空间:System.Net 3、HttpWebRequest对象不是利用new关键字创建的(通过构造函数)。而是利用Create()方法创建的。 4、你可能预计需要显示地调用一个“Send”方法,实际上不需要。 5、调用 HttpWebRequest.GetResponse()方法返回的是一个HttpWebResponse对象 6、你可以把HTTP响应的数据流 (stream)绑定到一个StreamReader对象,然后就可以通过ReadToEnd()方法把整个HTTP响应作为一个字符串取回。也可以通过 StreamReader.ReadLine()方法逐行取回HTTP响应的内容。
2. HttpWebRequest属性
下面是HttpWebRequest的一些属性,这些属性对于轻量级的自动化测试程序是非常重要的。- AllowAutoRedirect:获取或设置一个值,该值指示请求是否应跟随重定向响应。
- CookieContainer:获取或设置与此请求关联的cookie。
- Credentials:获取或设置请求的身份验证信息。
- KeepAlive:获取或设置一个值,该值指示是否与 Internet 资源建立持久性连接。
- MaximumAutomaticRedirections:获取或设置请求将跟随的重定向的最大数目。
- Proxy:获取或设置请求的代理信息。
- SendChunked:获取或设置一个值,该值指示是否将数据分段发送到 Internet 资源。
- Timeout:获取或设置请求的超时值。
- UserAgent:获取或设置 User-agent HTTP 标头的值
二、HttpWebRequest请求接口
HttpWebRequest提交数据方式其实就是GET和POST两种1. HttpWebRequest的作用:
HttpWebRequest对HTTP协议进行了完整的封装,对HTTP协议中的 Header, Content, Cookie 都做了属性和方法的支持,很容易就能编写出一个模拟浏览器自动登录的程序。2. HttpWebRequest提交数据方式:
程序使用HTTP协议和服务器交互主要是进行数据的提交,通常数据的提交是通过 GET 和 POST 两种方式来完成,1. GET 方式。
GET方式通过在网络地址附加参数来完成数据提交,比如在地址http://www.google.com/webhp?hl=zh-CN
中,前面部分http://www.google.com/webhp
表示数据提交的网址,后面部分<font style="color:rgb(77, 77, 77);"> hl=zh-CN</font>
表示附加的参数,其中 hl 表示一个键(key), zh-CN 表示这个键对应的值(value)。程序代码如下:
HttpWebRequest req =
(HttpWebRequest)HttpWebRequest.Create("http://www.google.com/webhp?hl=zh-CN");
req.Method = "GET";
using (WebResponse wr = req.GetResponse())
{
//在这里对接收到的页面内容进行处理
}
string htmlStr = string.Empty;
//创建一个客户端的Http请求实例
HttpWebRequest request = WebRequest.Create(requestUrl) as HttpWebRequest;
request.Method = "GET";
//获取当前Http请求的响应实例
HttpWebResponse response = request.GetResponse() as HttpWebResponse;
Stream responseStream = response.GetResponseStream();
using (StreamReader reader = new StreamReader(responseStream, Encoding.GetEncoding("UTF-8")))
{
htmlStr = reader.ReadToEnd();
}
responseStream.Close();
response.Close();
return htmlStr;
2. POST 方式。
POST 方式通过在页面内容中填写参数的方法来完成数据的提交,参数的格式和 GET 方式一样,是类似于 hl=zh-CN&newwindow=1 这样的结构。程序代码如下:
string param = "hl=zh-CN&newwindow=1"; //参数
byte[] bs = Encoding.ASCII.GetBytes(param); //参数转化为ascii码
HttpWebRequest req =
(HttpWebRequest) HttpWebRequest.Create("http://www.google.com/intl/zh-CN/" ); //创建request
req.Method = "POST"; //确定传值的方式,此处为post方式传值
req.ContentType = "application/x-www-form-urlencoded";
req.ContentLength = bs.Length;
using (Stream reqStream = req.GetRequestStream())
{
reqStream.Write(bs, 0, bs.Length);
}
using (WebResponse wr = req.GetResponse())
{
//在这里对接收到的页面内容进行处理
}
3. 使用 GET 方式提交中文数据。
GET 方式通过在网络地址中附加参数来完成数据提交,对于中文的编码,常用的有 gb2312 和 utf8 两种,用 gb2312 方式编码访问的程序代码如下:在上面的程序代码中,我们以 GET 方式访问了网址 http://www.baidu.com/s ,传递了参数“参数一=值一”,由于无法告知对方提交数据的编码类型,所以编码方式要以对方的网站为标准。常见的网站中, www.baidu.com (百度)的编码方式是 gb2312, www.google.com (谷歌)的编码方式是 utf8。
Encoding myEncoding = Encoding.GetEncoding("gb2312"); //确定用哪种中文编码方式
string address = "http://www.baidu.com/s?"+ HttpUtility.UrlEncode("参数一", myEncoding) + "=" + HttpUtility.UrlEncode("值一", myEncoding); //拼接数据提交的网址和经过中文编码后的中文参数
HttpWebRequest req =
(HttpWebRequest)HttpWebRequest.Create(address); //创建request
req.Method = "GET"; //确定传值方式,此处为get方式
using (WebResponse wr = req.GetResponse())
{
//在这里对接收到的页面内容进行处理
}
4. 使用 POST 方式提交中文数据。
POST 方式通过在页面内容中填写参数的方法来完成数据的提交,由于提交的参数中可以说明使用的编码方式,所以理论上能获得更大的兼容性。用 gb2312 方式编码访问的程序代码如下:从上面的代码可以看出, POST 中文数据的时候,先使用 UrlEncode 方法将中文字符转换为编码后的 ASCII 码,然后提交到服务器,提交的时候可以说明编码的方式,用来使对方服务器能够正确的解析。 以上列出了客户端程序使用HTTP协议与服务器交互的情况,常用的是 GET 和 POST 方式。 现在流行的 WebService 也是通过 HTTP 协议来交互的,使用的是 POST 方法。与以上稍有所不同的是, WebService 提交的数据内容和接收到的数据内容都是使用了 XML 方式编码。所以, HttpWebRequest 也可以使用在调用 WebService 的情况下。 C# HttpWebRequest提交数据方式的基本内容就向你介绍到这里,希望对你了解和学习C# HttpWebRequest提交数据方式有所帮助。
Encoding myEncoding = Encoding.GetEncoding("gb2312"); //确定中文编码方式。此处用gb2312
string param = HttpUtility.UrlEncode("参数一", myEncoding) + "=" + HttpUtility.UrlEncode("值一", myEncoding) + "&" + HttpUtility.UrlEncode("参数二", myEncoding) + "=" + HttpUtility.UrlEncode("值二", myEncoding);
byte[] postBytes = Encoding.ASCII.GetBytes(param); //将参数转化为assic码
HttpWebRequest req =
(HttpWebRequest) HttpWebRequest.Create( "http://www.baidu.com/s" );
req.Method = "POST";
req.ContentType = "application/x-www-form-urlencoded;charset=gb2312";
req.ContentLength = postBytes.Length;
using (Stream reqStream = req.GetRequestStream())
{
reqStream.Write(bs, 0, bs.Length);
}
using (WebResponse wr = req.GetResponse())
{
//在这里对接收到的页面内容进行处理
}
四、完整示例
1. demo
#region 公共方法
/// <summary>
/// Get数据接口
/// </summary>
/// <param name="getUrl">接口地址</param>
/// <returns></returns>
private static string GetWebRequest(string getUrl)
{
string responseContent = "";
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(getUrl);
request.ContentType = "application/json";
request.Method = "GET";
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
//在这里对接收到的页面内容进行处理
using (Stream resStream = response.GetResponseStream())
{
using (StreamReader reader = new StreamReader(resStream, Encoding.UTF8))
{
responseContent = reader.ReadToEnd().ToString();
}
}
return responseContent;
}
/// <summary>
/// Post数据接口
/// </summary>
/// <param name="postUrl">接口地址</param>
/// <param name="paramData">提交json数据</param>
/// <param name="dataEncode">编码方式(Encoding.UTF8)</param>
/// <returns></returns>
private static string PostWebRequest(string postUrl, string paramData, Encoding dataEncode)
{
string responseContent = string.Empty;
try
{
byte[] byteArray = dataEncode.GetBytes(paramData); //转化
HttpWebRequest webReq = (HttpWebRequest)WebRequest.Create(new Uri(postUrl));
webReq.Method = "POST";
webReq.ContentType = "application/x-www-form-urlencoded";
webReq.ContentLength = byteArray.Length;
using (Stream reqStream = webReq.GetRequestStream())
{
reqStream.Write(byteArray, 0, byteArray.Length);//写入参数
//reqStream.Close();
}
using (HttpWebResponse response = (HttpWebResponse)webReq.GetResponse())
{
//在这里对接收到的页面内容进行处理
using (StreamReader sr = new StreamReader(response.GetResponseStream(), Encoding.Default))
{
responseContent = sr.ReadToEnd().ToString();
}
}
}
catch (Exception ex)
{
return ex.Message;
}
return responseContent;
}
#endregion
2. post支持cookie
/// <summary>
/// 发起Post请求(采用HttpWebRequest,支持传Cookie)
/// </summary>
/// <param name="strUrl">请求Url</param>
/// <param name="formData">发送的表单数据</param>
/// <param name="strResult">返回请求结果(如果请求失败,返回异常消息)</param>
/// <param name="cookieContainer">随同HTTP请求发送的Cookie信息,如果不需要身份验证可以为空</param>
/// <returns>返回:是否请求成功</returns>
public static bool HttpPost(string strUrl, Dictionary<string, string> formData, CookieContainer cookieContainer, out string strResult)
{
string strPostData = null;
if (formData != null && formData.Count > 0)
{
StringBuilder sbData = new StringBuilder();
int i = 0;
foreach (KeyValuePair<string, string> data in formData)
{
if (i > 0)
{
sbData.Append("&");
}
sbData.AppendFormat("{0}={1}", data.Key, data.Value);
i++;
}
strPostData = sbData.ToString();
}
byte[] postBytes = string.IsNullOrEmpty(strPostData) ? new byte[0] : Encoding.UTF8.GetBytes(strPostData);
return HttpPost(strUrl, postBytes, cookieContainer, out strResult);
}
3. post上传文件
/// <summary>
/// 发起Post文件请求(采用HttpWebRequest,支持传Cookie)
/// </summary>
/// <param name="strUrl">请求Url</param>
/// <param name="strFilePostName">上传文件的PostName</param>
/// <param name="strFilePath">上传文件路径</param>
/// <param name="cookieContainer">随同HTTP请求发送的Cookie信息,如果不需要身份验证可以为空</param>
/// <param name="strResult">返回请求结果(如果请求失败,返回异常消息)</param>
/// <returns>返回:是否请求成功</returns>
public static bool HttpPostFile(string strUrl, string strFilePostName, string strFilePath, CookieContainer cookieContainer, out string strResult)
{
HttpWebRequest request = null;
FileStream fileStream = FileHelper.GetFileStream(strFilePath);
try
{
if (fileStream == null)
{
throw new FileNotFoundException();
}
request = (HttpWebRequest)WebRequest.Create(strUrl);
request.Method = "POST";
request.KeepAlive = false;
request.Timeout = 30000;
if (cookieContainer != null)
{
request.CookieContainer = cookieContainer;
}
string boundary = string.Format("---------------------------{0}", DateTime.Now.Ticks.ToString("x"));
byte[] header = Encoding.UTF8.GetBytes(string.Format("--{0}\r\nContent-Disposition: form-data; name=\"{1}\"; filename=\"{2}\"\r\nContent-Type: application/octet-stream\r\n\r\n",
boundary, strFilePostName, Path.GetFileName(strFilePath)));
byte[] footer = Encoding.UTF8.GetBytes(string.Format("\r\n--{0}--\r\n", boundary));
request.ContentType = string.Format("multipart/form-data; boundary={0}", boundary);
request.ContentLength = header.Length + fileStream.Length + footer.Length;
using (Stream reqStream = request.GetRequestStream())
{
// 写入分割线及数据信息
reqStream.Write(header, 0, header.Length);
// 写入文件
FileHelper.WriteFile(reqStream, fileStream);
// 写入尾部
reqStream.Write(footer, 0, footer.Length);
}
strResult = GetResponseResult(request, cookieContainer);
}
catch (Exception ex)
{
strResult = ex.Message;
return false;
}
finally
{
if (request != null)
{
request.Abort();
}
if (fileStream != null)
{
fileStream.Close();
}
}
return true;
}
/// <summary>
/// 获取请求结果字符串
/// </summary>
/// <param name="request">请求对象(发起请求之后)</param>
/// <param name="cookieContainer">随同HTTP请求发送的Cookie信息,如果不需要身份验证可以为空</param>
/// <returns>返回请求结果字符串</returns>
private static string GetResponseResult(HttpWebRequest request, CookieContainer cookieContainer = null)
{
using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
{
if (cookieContainer != null)
{
response.Cookies = cookieContainer.GetCookies(response.ResponseUri);
}
using (Stream rspStream = response.GetResponseStream())
{
using (StreamReader reader = new StreamReader(rspStream, Encoding.UTF8))
{
return reader.ReadToEnd();
}
}
}
}
4. OAuth头部
//构造OAuth头部
StringBuilder oauthHeader = new StringBuilder();
oauthHeader.AppendFormat("OAuth realm=\"\", oauth_consumer_key={0}, ", apiKey);
oauthHeader.AppendFormat("oauth_nonce={0}, ", nonce);
oauthHeader.AppendFormat("oauth_timestamp={0}, ", timeStamp);
oauthHeader.AppendFormat("oauth_signature_method={0}, ", "HMAC-SHA1");
oauthHeader.AppendFormat("oauth_version={0}, ", "1.0");
oauthHeader.AppendFormat("oauth_signature={0}, ", sig);
oauthHeader.AppendFormat("oauth_token={0}", accessToken);
//构造请求
StringBuilder requestBody = new StringBuilder("");
Encoding encoding = Encoding.GetEncoding("utf-8");
byte[] data = encoding.GetBytes(requestBody.ToString());
// Http Request的设置
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(uri);
request.Headers.Set("Authorization", oauthHeader.ToString());
//request.Headers.Add("Authorization", authorization);
request.ContentType = "application/atom+xml";
request.Method = "GET";
五、C#通过WebClient/HttpWebRequest实现http的post/get方法
1. POST方法(httpWebRequest)
//body是要传递的参数,格式"roleId=1&uid=2"
//post的cotentType填写:"application/x-www-form-urlencoded"
//soap填写:"text/xml; charset=utf-8"
public static string PostHttp(string url, string body, string contentType)
{
HttpWebRequest httpWebRequest = (HttpWebRequest)WebRequest.Create(url);
httpWebRequest.ContentType = contentType;
httpWebRequest.Method = "POST";
httpWebRequest.Timeout = 20000;
byte[] btBodys = Encoding.UTF8.GetBytes(body);
httpWebRequest.ContentLength = btBodys.Length;
httpWebRequest.GetRequestStream().Write(btBodys, 0, btBodys.Length);
HttpWebResponse httpWebResponse = (HttpWebResponse)httpWebRequest.GetResponse();
StreamReader streamReader = new StreamReader(httpWebResponse.GetResponseStream());
string responseContent = streamReader.ReadToEnd();
httpWebResponse.Close();
streamReader.Close();
httpWebRequest.Abort();
httpWebResponse.Close();
return responseContent;
}
2. POST方法(WebClient)
/// <summary>
/// 通过WebClient类Post数据到远程地址,需要Basic认证;
/// 调用端自己处理异常
/// </summary>
/// <param name="uri"></param>
/// <param name="paramStr">name=张三&age=20</param>
/// <param name="encoding">请先确认目标网页的编码方式</param>
/// <param name="username"></param>
/// <param name="password"></param>
/// <returns></returns>
public static string Request_WebClient(string uri, string paramStr, Encoding encoding, string username, string password)
{
if (encoding == null)
encoding = Encoding.UTF8;
string result = string.Empty;
WebClient wc = new WebClient();
// 采取POST方式必须加的Header
wc.Headers.Add("Content-Type", "application/x-www-form-urlencoded");
byte[] postData = encoding.GetBytes(paramStr);
if (!string.IsNullOrEmpty(username) && !string.IsNullOrEmpty(password))
{
wc.Credentials = GetCredentialCache(uri, username, password);
wc.Headers.Add("Authorization", GetAuthorization(username, password));
}
byte[] responseData = wc.UploadData(uri, "POST", postData); // 得到返回字符流
return encoding.GetString(responseData);// 解码
}
3. Get方法(httpWebRequest)
public static string GetHttp(string url, HttpContext httpContext)
{
string queryString = "?";
foreach (string key in httpContext.Request.QueryString.AllKeys)
{
queryString += key + "=" + httpContext.Request.QueryString[key] + "&";
}
queryString = queryString.Substring(0, queryString.Length - 1);
HttpWebRequest httpWebRequest = (HttpWebRequest)WebRequest.Create(url + queryString);
httpWebRequest.ContentType = "application/json";
httpWebRequest.Method = "GET";
httpWebRequest.Timeout = 20000;
//byte[] btBodys = Encoding.UTF8.GetBytes(body);
//httpWebRequest.ContentLength = btBodys.Length;
//httpWebRequest.GetRequestStream().Write(btBodys, 0, btBodys.Length);
HttpWebResponse httpWebResponse = (HttpWebResponse)httpWebRequest.GetResponse();
StreamReader streamReader = new StreamReader(httpWebResponse.GetResponseStream());
string responseContent = streamReader.ReadToEnd();
httpWebResponse.Close();
streamReader.Close();
return responseContent;
}
4. basic验证的WebRequest/WebResponse
/// <summary>
/// 通过 WebRequest/WebResponse 类访问远程地址并返回结果,需要Basic认证;
/// 调用端自己处理异常
/// </summary>
/// <param name="uri"></param>
/// <param name="timeout">访问超时时间,单位毫秒;如果不设置超时时间,传入0</param>
/// <param name="encoding">如果不知道具体的编码,传入null</param>
/// <param name="username"></param>
/// <param name="password"></param>
/// <returns></returns>
public static string Request_WebRequest(string uri, int timeout, Encoding encoding, string username, string password)
{
string result = string.Empty;
WebRequest request = WebRequest.Create(new Uri(uri));
if (!string.IsNullOrEmpty(username) && !string.IsNullOrEmpty(password))
{
request.Credentials = GetCredentialCache(uri, username, password);
request.Headers.Add("Authorization", GetAuthorization(username, password));
}
if (timeout > 0)
request.Timeout = timeout;
WebResponse response = request.GetResponse();
Stream stream = response.GetResponseStream();
StreamReader sr = encoding == null ? new StreamReader(stream) : new StreamReader(stream, encoding);
result = sr.ReadToEnd();
sr.Close();
stream.Close();
return result;
}
#region # 生成 Http Basic 访问凭证 #
private static CredentialCache GetCredentialCache(string uri, string username, string password)
{
string authorization = string.Format("{0}:{1}", username, password);
CredentialCache credCache = new CredentialCache();
credCache.Add(new Uri(uri), "Basic", new NetworkCredential(username, password));
return credCache;
}
private static string GetAuthorization(string username, string password)
{
string authorization = string.Format("{0}:{1}", username, password);
return "Basic " + Convert.ToBase64String(new ASCIIEncoding().GetBytes(authorization));
}
#endregion
六、遇见问题
1. post数据时报错:远程服务器返回错误: (400) 错误的请求
报400说是传的数据格式不对Content_Type为:application/json,配的数据格式有些麻烦,特别数多层,单层还好。
例如,我本传的数据是这个的json:
这时候,postData应该为:{“key1”: {\”key11\”: \”value11\”,\”key12\”: \”value12\”},”key2”: “value2”} c#里赋值写法为:(这里建议将json格式数据通过json工具转义,避免自己转移带来不必要的错误)
{
"key1": {
"key11": "value11",
"key12": "value12"
},
"key2": "value2"
}
post的方法:
{
\"key1\": {
\"key11\": \"value11\",
\"key12\": \"value12\"
},
\"key2\": \"value2\"
}
如果posData的格式写错,运行后报错(using (var httpWebResponse = webrequest.GetResponse())):System.Net.WebException: 远程服务器返回错误: (400) 错误的请求。 在System.Net.HttpWebRequest.GetResponse() 。
protected string PostUrl(string url, string postData)
{
try
{
HttpWebRequest webrequest = (HttpWebRequest)HttpWebRequest.Create(url);
webrequest.Method = "post";
webrequest.ContentType = "application/json;charset=utf-8";
byte[] postdatabyte = Encoding.UTF8.GetBytes(postData);
webrequest.ContentLength = postdatabyte.Length;
Stream stream;
stream = webrequest.GetRequestStream();
stream.Write(postdatabyte, 0, postdatabyte.Length);
stream.Close();
using (var httpWebResponse = webrequest.GetResponse())
using (StreamReader responseStream = new StreamReader(httpWebResponse.GetResponseStream()))
{
String ret = responseStream.ReadToEnd();
string result = ret.ToString();
return result;
}
}
catch (Exception ex)
{
HttpContext.Current.Response.Write(ex);
return "";
}
}