常用方法记录

/// <summary>   /// 得到站点用户IP   /// </summary>   /// <returns></returns>   public static string getUserIP()   {       return HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"].ToString();   }     /// <summary>   /// 去除字符串最后一个','号   /// </summary>   /// <param name="chr">:要做处理的字符串</param>   /// <returns>返回已处理的字符串</returns>   public static string Lost(string chr)   {       if (chr == null || chr == string.Empty)        {           return "";        }       else       {            chr = chr.Remove(chr.LastIndexOf(","));           return chr;        }   }     /// <summary>   /// 去除字符串第一个'/'号   /// </summary>   /// <param name="chr">要做处理的字符串</param>   /// <returns>返回已处理的字符串</returns>   public static string lostfirst(string chr)   {       string flg = "";       if (chr != string.Empty || chr != null)        {           if (chr.Substring(0, 1) == "/")                flg = chr.Replace(chr.Substring(0, 1), "");           else               flg = chr;        }       return flg;   }     /// <summary>   /// 替换html中的特殊字符   /// </summary>   /// <param name="theString">需要进行替换的文本。</param>   /// <returns>替换完的文本。</returns>   public static string HtmlEncode(string theString)   {        theString = theString.Replace(">", ">");        theString = theString.Replace("<", "<");        theString = theString.Replace("   ", "   ");        theString = theString.Replace("   ", "   ");        theString = theString.Replace("\"", """);        theString = theString.Replace("\'", "'");        theString = theString.Replace("\n", "<br/> ");       return theString;   }     /// <summary>   /// 恢复html中的特殊字符   /// </summary>   /// <param name="theString">需要恢复的文本。</param>   /// <returns>恢复好的文本。</returns>   public static string HtmlDiscode(string theString)   {        theString = theString.Replace(">", ">");        theString = theString.Replace("<", "<");        theString = theString.Replace(" ", " ");        theString = theString.Replace("   ", "   ");        theString = theString.Replace(""", "\"");        theString = theString.Replace("'", "\'");        theString = theString.Replace("<br/> ", "\n");       return theString;   }         /// <summary>   /// 生成随机数字   /// </summary>   /// <param name="length">生成长度</param>   /// <returns></returns>   public static string Number(int Length)   {       return Number(Length, false);   }     /// <summary>   /// 生成随机数字   /// </summary>   /// <param name="Length">生成长度</param>   /// <param name="Sleep">是否要在生成前将当前线程阻止以避免重复</param>   /// <returns></returns>   public static string Number(int Length, bool Sleep)   {       if (Sleep)            System.Threading.Thread.Sleep(3);       string result = "";        System.Random random = new Random();       for (int i = 0; i < Length; i++)        {            result += random.Next(10).ToString();        }       return result;   }     //弹出对话框   public static void salert(string str)   {            HttpContext.Current.Response.Write("<script>alert('" + str + "');</script>");   }         /// <summary>       /// 显示消息提示框，并回到前一页面       /// </summary>       /// <param name="page">当前页面指针，一般为this</param>       /// <param name="strMsg">提示信息</param>       public static void ShowGoHistory(System.Web.UI.Page page, string strMsg)        {            page.ClientScript.RegisterStartupScript(page.GetType(), "message", "<script language='javascript' defer>alert('" + strMsg.ToString() + "');window.history.go(-1);</script>");        }         /// <summary>       /// 显示消息提示对话框，并进行页面跳转       /// </summary>       /// <param name="page">当前页面指针，一般为this</param>       /// <param name="strMsg">提示信息</param>       /// <param name="url"> 跳转的目标URL</param>       public static void ShowRedirect(System.Web.UI.Page page, string strMsg, string url)        {            StringBuilder Builder = new StringBuilder();            Builder.Append("<script language='javascript' defer>");            Builder.AppendFormat("alert('{0}');", strMsg);            Builder.AppendFormat("top.location.href='{0}'", url);            Builder.Append("</script>");            page.ClientScript.RegisterStartupScript(page.GetType(), "message", Builder.ToString());        }     //为了插入单引号   public static string delSingle(string str)   {           return str.Replace("'", "''");   }     //由gridviw导出为Excel   public static void ToExcel(System.Web.UI.Control ctl)   {        HttpContext.Current.Response.AppendHeader("Content-Disposition", "attachment;filename=Excel.xls");        HttpContext.Current.Response.Charset = "UTF-8";        HttpContext.Current.Response.ContentEncoding = System.Text.Encoding.Default;        HttpContext.Current.Response.ContentType = "application/ms-excel";//image/JPEG;text/HTML;image/GIF;vnd.ms-excel/msword        ctl.Page.EnableViewState = false;        System.IO.StringWriter tw = new System.IO.StringWriter();        System.Web.UI.HtmlTextWriter hw = new System.Web.UI.HtmlTextWriter(tw);        ctl.RenderControl(hw);        HttpContext.Current.Response.Write(tw.ToString());        HttpContext.Current.Response.End();   }     ///using System.Security.Cryptography;   ///using System.Text;   /// <summary>   /// MD5函数   /// </summary>   /// <param name="str">原始字符串</param>   /// <returns>MD5结果</returns>   public static string MD5(string str)   {       byte[] b = Encoding.Default.GetBytes(str);        b = new MD5CryptoServiceProvider().ComputeHash(b);       string ret = "";       for (int i = 0; i < b.Length; i++)            ret += b[i].ToString("x").PadLeft(2, '0');       return ret;   }       ///using System.Net;       ///using System.IO;     /// <summary>       /// 根据Url获得源文件内容       /// </summary>       /// <param name="url">合法的Url地址</param>       /// <returns></returns>       public static string GetSourceTextByUrl(string url)       {            WebRequest request = WebRequest.Create(url);            request.Timeout = 20000;//20秒超时            WebResponse response = request.GetResponse();                  Stream resStream = response.GetResponseStream();            StreamReader sr = new StreamReader(resStream);           return sr.ReadToEnd();       }