在客户机向服务器请求数据的时候，最常用的是GET和POST方法。
两者的主要区别是，GET把参数放到URL里发送请求，POST把参数放到包体里发送请求，相较于GET，POST请求更加安全。
一般POST请求的包体里放的是JSON格式的数据。
这里将C#程序里用的GET方法和POST方法封装成一个类，方便调用。
类里的HttpGet方法是用来发送GET请求的，包含重载方法，一个是包含请求头的，一个是不包含请求头的。
HttpPost方法用来发送Post请求，可以将json的字符串数据发送到指定地址中。
class HttpRequest
{
///
/// GET方式请求数据
///
/// 请求地址
///
public static string HttpGet(string url)
{
HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(url);
request.Method = "GET";
request.ContentType = "application/x-www-form-urlencoded";
request.Accept = "*/*";
request.Timeout = 15000;
request.AllowAutoRedirect = false;
WebResponse response = null;
string responseStr = null;
try
{
response = request.GetResponse();
if (response != null)
{
StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.UTF8);
responseStr = reader.ReadToEnd();
reader.Close();
}
}
catch (Exception)
{
throw;
}
finally
{
request = null;
response = null;
}
return responseStr;
}
///
/// GET方式请求数据
///
/// 请求地址
/// 请求头名称
/// 请求头值
///
public static string HttpGet(string url, string header, string headerValue)
{
HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(url);
request.Method = "GET";
request.ContentType = "application/x-www-form-urlencoded";
request.Accept = "*/*";
request.Timeout = 10000;
request.AllowAutoRedirect = false;
//添加报头
request.Headers.Add(header, headerValue);
WebResponse response = null;
string responseStr = null;
try
{
response = request.GetResponse();
if (response != null)
{
StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.UTF8);
responseStr = reader.ReadToEnd();
reader.Close();
}
}
catch (Exception)
{
throw;
}
finally
{
request = null;
response = null;
}
return responseStr;
}
///
/// POST方式请求数据
///
/// 请求地址
/// POST提交数据内容(utf-8编码的json)
///
public static string HttpPost(string url, string content)
{
Encoding e = null;
Regex s_charsetRegex = new Regex("charset=([^;]*);?");
HttpWebRequest req = WebRequest.CreateHttp(url);
var buffer = Encoding.UTF8.GetBytes(content);
req.Method = "POST";
req.ContentType = "application/json";
req.ContentLength = buffer.Length;
using (var fs = req.GetRequestStream())
{
fs.Write(buffer, 0, buffer.Length);
fs.Flush();
}
WebResponse resp = null;
try
{
resp = req.GetResponse();
}
catch (WebException ex)
{
resp = ex.Response;
if (resp != null)
{
resp.Close();
}
throw;
}
var ns = resp.GetResponseStream();
Stream stream = ns;
if (e == null)
{
if (resp.SupportsHeaders)
{
var m = s_charsetRegex.Match(resp.ContentType);
if (m.Success)
{
e = Encoding.GetEncoding(m.Groups[1].Value);
}
var contentEncoding = resp.Headers.Get("Content-Encoding");
if (contentEncoding == "gzip")
{
stream = new GZipStream(ns, CompressionMode.Decompress);
}
else if (contentEncoding == "deflate")
{
stream = new DeflateStream(ns, CompressionMode.Decompress);
}
}
if (e == null)
{
e = Encoding.UTF8;
}
}
var reader = new StreamReader(stream, e);
return reader.ReadToEnd();
}
}
如果出现"WebRequest"未包含"CreateHttp"的定义这一类的问题，说明项目的目标框架版本太低，需要修改成.net framework 4.5或更高版本。
[caption id="" align="aligncenter" width="440"]
遇到图中报错时需升级目标框架版本[/caption]
