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;
    }
}