Web操作帮助类

/// <summary>
	/// Web操作
	/// </summary>
	public static class WebHelper
	{
		/// <summary>
		/// 获取主机名,即域名，
		/// 范例：用户输入网址http://www.a.com/b.htm?a=1&amp;b=2，
		/// 返回值为: www.a.com
		/// </summary>
		public static string Host
		{
			get
			{
				return HttpContext.Current.Request.Url.Host;
			}
		}
		/// <summary>
		/// 解析相对Url
		/// </summary>
		/// <param name="relativeUrl">相对Url</param>
		public static string ResolveUrl(string relativeUrl)
		{
			bool flag = string.IsNullOrWhiteSpace(relativeUrl);
			string result;
			if (flag)
			{
				result = string.Empty;
			}
			else
			{
				relativeUrl = relativeUrl.Replace("\\", "/");
				bool flag2 = relativeUrl.StartsWith("/");
				if (flag2)
				{
					result = relativeUrl;
				}
				else
				{
					bool flag3 = relativeUrl.Contains("://");
					if (flag3)
					{
						result = relativeUrl;
					}
					else
					{
						result = VirtualPathUtility.ToAbsolute(relativeUrl);
					}
				}
			}
			return result;
		}
		/// <summary>
		/// 对html字符串进行编码
		/// </summary>
		/// <param name="html">html字符串</param>
		public static string HtmlEncode(string html)
		{
			return HttpUtility.HtmlEncode(html);
		}
		/// <summary>
		/// 对html字符串进行解码
		/// </summary>
		/// <param name="html">html字符串</param>
		public static string HtmlDecode(string html)
		{
			return HttpUtility.HtmlDecode(html);
		}
		/// <summary>
		/// 对Url进行编码
		/// </summary>
		/// <param name="url">url</param>
		/// <param name="isUpper">编码字符是否转成大写,范例,"http://"转成"http%3A%2F%2F"</param>
		public static string UrlEncode(string url, bool isUpper = false)
		{
			return WebHelper.UrlEncode(url, Encoding.UTF8, isUpper);
		}
		/// <summary>
		/// 对Url进行编码
		/// </summary>
		/// <param name="url">url</param>
		/// <param name="encoding">字符编码</param>
		/// <param name="isUpper">编码字符是否转成大写,范例,"http://"转成"http%3A%2F%2F"</param>
		public static string UrlEncode(string url, Encoding encoding, bool isUpper = false)
		{
			string text = HttpUtility.UrlEncode(url, encoding);
			bool flag = !isUpper;
			string result;
			if (flag)
			{
				result = text;
			}
			else
			{
				result = WebHelper.GetUpperEncode(text);
			}
			return result;
		}
		/// <summary>
		/// 获取大写编码字符串
		/// </summary>
		private static string GetUpperEncode(string encode)
		{
			StringBuilder stringBuilder = new StringBuilder();
			int num = -2147483648;
			for (int i = 0; i < encode.Length; i++)
			{
				string text = encode[i].ToString();
				bool flag = text == "%";
				if (flag)
				{
					num = i;
				}
				bool flag2 = i - num == 1 || i - num == 2;
				if (flag2)
				{
					text = text.ToUpper();
				}
				stringBuilder.Append(text);
			}
			return stringBuilder.ToString();
		}
		/// <summary>
		/// 对Url进行解码,对于javascript的encodeURIComponent函数编码参数,应使用utf-8字符编码来解码
		/// </summary>
		/// <param name="url">url</param>
		public static string UrlDecode(string url)
		{
			return HttpUtility.UrlDecode(url);
		}
		/// <summary>
		/// 对Url进行解码,对于javascript的encodeURIComponent函数编码参数,应使用utf-8字符编码来解码
		/// </summary>
		/// <param name="url">url</param>
		/// <param name="encoding">字符编码,对于javascript的encodeURIComponent函数编码参数,应使用utf-8字符编码来解码</param>
		public static string UrlDecode(string url, Encoding encoding)
		{
			return HttpUtility.UrlDecode(url, encoding);
		}
		/// <summary>
		/// 写Session
		/// </summary>
		/// <typeparam name="T">Session键值的类型</typeparam>
		/// <param name="key">Session的键名</param>
		/// <param name="value">Session的键值</param>
		public static void WriteSession<T>(string key, T value)
		{
			bool flag = string.IsNullOrWhiteSpace(key);
			if (!flag)
			{
				HttpContext.Current.Session[key] = value;
			}
		}
		/// <summary>
		/// 写Session
		/// </summary>
		/// <param name="key">Session的键名</param>
		/// <param name="value">Session的键值</param>
		public static void WriteSession(string key, string value)
		{
			WebHelper.WriteSession<string>(key, value);
		}
		/// <summary>
		/// 读取Session的值
		/// </summary>
		/// <param name="key">Session的键名</param>        
		public static string GetSession(string key)
		{
			bool flag = string.IsNullOrWhiteSpace(key);
			string result;
			if (flag)
			{
				result = string.Empty;
			}
			else
			{
				result = (HttpContext.Current.Session[key] as string);
			}
			return result;
		}
		/// <summary>
		/// 删除指定Session
		/// </summary>
		/// <param name="key">Session的键名</param>
		public static void RemoveSession(string key)
		{
			bool flag = string.IsNullOrWhiteSpace(key);
			if (!flag)
			{
				HttpContext.Current.Session.Contents.Remove(key);
			}
		}
		/// <summary>
		/// 写cookie值
		/// </summary>
		/// <param name="strName">名称</param>
		/// <param name="strValue">值</param>
		public static void WriteCookie(string strName, string strValue)
		{
			HttpCookie httpCookie = HttpContext.Current.Request.Cookies[strName];
			bool flag = httpCookie == null;
			if (flag)
			{
				httpCookie = new HttpCookie(strName);
			}
			httpCookie.Value = strValue;
			HttpContext.Current.Response.AppendCookie(httpCookie);
		}
		/// <summary>
		/// 写cookie值
		/// </summary>
		/// <param name="strName">名称</param>
		/// <param name="strValue">值</param>
		/// <param name="strValue">过期时间(分钟)</param>
		public static void WriteCookie(string strName, string strValue, int expires)
		{
			HttpCookie httpCookie = HttpContext.Current.Request.Cookies[strName];
			bool flag = httpCookie == null;
			if (flag)
			{
				httpCookie = new HttpCookie(strName);
			}
			httpCookie.Value = strValue;
			httpCookie.Expires = DateTime.Now.AddMinutes((double)expires);
			HttpContext.Current.Response.AppendCookie(httpCookie);
		}
		/// <summary>
		/// 读cookie值
		/// </summary>
		/// <param name="strName">名称</param>
		/// <returns>cookie值</returns>
		public static string GetCookie(string strName)
		{
			bool flag = HttpContext.Current.Request.Cookies != null && HttpContext.Current.Request.Cookies[strName] != null;
			string result;
			if (flag)
			{
				result = HttpContext.Current.Request.Cookies[strName].Value.ToString();
			}
			else
			{
				result = "";
			}
			return result;
		}
		/// <summary>
		/// 删除Cookie对象
		/// </summary>
		/// <param name="CookiesName">Cookie对象名称</param>
		public static void RemoveCookie(string CookiesName)
		{
			HttpCookie httpCookie = new HttpCookie(CookiesName.Trim());
			httpCookie.Expires = DateTime.Now.AddYears(-5);
			HttpContext.Current.Response.Cookies.Add(httpCookie);
		}
		/// <summary>
		/// 获取有效客户端文件控件集合,文件控件必须上传了内容，为空将被忽略,
		/// 注意:Form标记必须加入属性 enctype="multipart/form-data",服务器端才能获取客户端file控件.
		/// </summary>
		public static List<HttpPostedFile> GetFileControls()
		{
			List<HttpPostedFile> list = new List<HttpPostedFile>();
			HttpFileCollection files = HttpContext.Current.Request.Files;
			bool flag = files.Count == 0;
			List<HttpPostedFile> result;
			if (flag)
			{
				result = list;
			}
			else
			{
				for (int i = 0; i < files.Count; i++)
				{
					HttpPostedFile httpPostedFile = files[i];
					bool flag2 = httpPostedFile.ContentLength == 0;
					if (!flag2)
					{
						list.Add(files[i]);
					}
				}
				result = list;
			}
			return result;
		}
		/// <summary>
		/// 获取第一个有效客户端文件控件,文件控件必须上传了内容，为空将被忽略,
		/// 注意:Form标记必须加入属性 enctype="multipart/form-data",服务器端才能获取客户端file控件.
		/// </summary>
		public static HttpPostedFile GetFileControl()
		{
			List<HttpPostedFile> fileControls = WebHelper.GetFileControls();
			bool flag = fileControls == null || fileControls.Count == 0;
			HttpPostedFile result;
			if (flag)
			{
				result = null;
			}
			else
			{
				result = fileControls[0];
			}
			return result;
		}
		/// <summary>
		/// 请求网络资源,返回响应的文本
		/// </summary>
		/// <param name="url">网络资源地址</param>
		public static string HttpWebRequest(string url)
		{
			return WebHelper.HttpWebRequest(url, string.Empty, Encoding.GetEncoding("utf-8"), false, "application/x-www-form-urlencoded", null, 120000);
		}
		/// <summary>
		/// 请求网络资源,返回响应的文本
		/// </summary>
		/// <param name="url">网络资源Url地址</param>
		/// <param name="parameters">提交的参数,格式：参数1=参数值1&amp;参数2=参数值2</param>
		public static string HttpWebRequest(string url, string parameters)
		{
			return WebHelper.HttpWebRequest(url, parameters, Encoding.GetEncoding("utf-8"), true, "application/x-www-form-urlencoded", null, 120000);
		}
		/// <summary>
		/// 请求网络资源,返回响应的文本
		/// </summary>
		/// <param name="url">网络资源地址</param>
		/// <param name="parameters">提交的参数,格式：参数1=参数值1&amp;参数2=参数值2</param>
		/// <param name="encoding">字符编码</param>
		/// <param name="isPost">是否Post提交</param>
		/// <param name="contentType">内容类型</param>
		/// <param name="cookie">Cookie容器</param>
		/// <param name="timeout">超时时间</param>
		public static string HttpWebRequest(string url, string parameters, Encoding encoding, bool isPost = false, string contentType = "application/x-www-form-urlencoded", CookieContainer cookie = null, int timeout = 120000)
		{
			HttpWebRequest httpWebRequest = (HttpWebRequest)WebRequest.Create(url);
			httpWebRequest.Timeout = timeout;
			httpWebRequest.CookieContainer = cookie;
			if (isPost)
			{
				byte[] bytes = encoding.GetBytes(parameters);
				httpWebRequest.Method = "POST";
				httpWebRequest.ContentType = contentType;
				httpWebRequest.ContentLength = (long)bytes.Length;
				using (Stream requestStream = httpWebRequest.GetRequestStream())
				{
					requestStream.Write(bytes, 0, bytes.Length);
				}
			}
			HttpWebResponse httpWebResponse = (HttpWebResponse)httpWebRequest.GetResponse();
			string result;
			string text;
			using (Stream responseStream = httpWebResponse.GetResponseStream())
			{
				bool flag = responseStream == null;
				if (flag)
				{
					result = string.Empty;
					return result;
				}
				using (StreamReader streamReader = new StreamReader(responseStream, encoding))
				{
					text = streamReader.ReadToEnd();
				}
			}
			result = text;
			return result;
		}
		/// <summary>
		/// 去除HTML标记
		/// </summary>
		/// <param name="NoHTML">包括HTML的源码 </param>
		/// <returns>已经去除后的文字</returns>
		public static string NoHtml(string Htmlstring)
		{
			Htmlstring = Regex.Replace(Htmlstring, "<script[^>]*?>.*?</script>", "", RegexOptions.IgnoreCase);
			Htmlstring = Regex.Replace(Htmlstring, "<(.[^>]*)>", "", RegexOptions.IgnoreCase);
			Htmlstring = Regex.Replace(Htmlstring, "([\\r\\n])[\\s]+", "", RegexOptions.IgnoreCase);
			Htmlstring = Regex.Replace(Htmlstring, "-->", "", RegexOptions.IgnoreCase);
			Htmlstring = Regex.Replace(Htmlstring, "<!--.*", "", RegexOptions.IgnoreCase);
			Htmlstring = Regex.Replace(Htmlstring, "&(quot|#34);", "\"", RegexOptions.IgnoreCase);
			Htmlstring = Regex.Replace(Htmlstring, "&(amp|#38);", "&", RegexOptions.IgnoreCase);
			Htmlstring = Regex.Replace(Htmlstring, "&(lt|#60);", "<", RegexOptions.IgnoreCase);
			Htmlstring = Regex.Replace(Htmlstring, "&(gt|#62);", ">", RegexOptions.IgnoreCase);
			Htmlstring = Regex.Replace(Htmlstring, "&(nbsp|#160);", " ", RegexOptions.IgnoreCase);
			Htmlstring = Regex.Replace(Htmlstring, "&(iexcl|#161);", "¡", RegexOptions.IgnoreCase);
			Htmlstring = Regex.Replace(Htmlstring, "&(cent|#162);", "¢", RegexOptions.IgnoreCase);
			Htmlstring = Regex.Replace(Htmlstring, "&(pound|#163);", "£", RegexOptions.IgnoreCase);
			Htmlstring = Regex.Replace(Htmlstring, "&(copy|#169);", "©", RegexOptions.IgnoreCase);
			Htmlstring = Regex.Replace(Htmlstring, "&#(\\d+);", "", RegexOptions.IgnoreCase);
			Htmlstring = Regex.Replace(Htmlstring, "&hellip;", "", RegexOptions.IgnoreCase);
			Htmlstring = Regex.Replace(Htmlstring, "&mdash;", "", RegexOptions.IgnoreCase);
			Htmlstring = Regex.Replace(Htmlstring, "&ldquo;", "", RegexOptions.IgnoreCase);
			Htmlstring.Replace("<", "");
			Htmlstring = Regex.Replace(Htmlstring, "&rdquo;", "", RegexOptions.IgnoreCase);
			Htmlstring.Replace(">", "");
			Htmlstring.Replace("\r\n", "");
			Htmlstring = HttpContext.Current.Server.HtmlEncode(Htmlstring).Trim();
			return Htmlstring;
		}
		/// <summary>
		/// 格式化文本（防止SQL注入）
		/// </summary>
		/// <param name="str"></param>
		/// <returns></returns>
		public static string Formatstr(string html)
		{
			Regex regex = new Regex("<script[\\s\\S]+</script *>", RegexOptions.IgnoreCase);
			Regex regex2 = new Regex(" href *= *[\\s\\S]*script *:", RegexOptions.IgnoreCase);
			Regex regex3 = new Regex(" on[\\s\\S]*=", RegexOptions.IgnoreCase);
			Regex regex4 = new Regex("<iframe[\\s\\S]+</iframe *>", RegexOptions.IgnoreCase);
			Regex regex5 = new Regex("<frameset[\\s\\S]+</frameset *>", RegexOptions.IgnoreCase);
			Regex regex6 = new Regex("select", RegexOptions.IgnoreCase);
			Regex regex7 = new Regex("update", RegexOptions.IgnoreCase);
			Regex regex8 = new Regex("delete", RegexOptions.IgnoreCase);
			html = regex.Replace(html, "");
			html = regex2.Replace(html, "");
			html = regex3.Replace(html, " _disibledevent=");
			html = regex4.Replace(html, "");
			html = regex6.Replace(html, "s_elect");
			html = regex7.Replace(html, "u_pudate");
			html = regex8.Replace(html, "d_elete");
			html = html.Replace("'", "’");
			html = html.Replace("&nbsp;", " ");
			return html;
		}
	}