djyweb_ams/ams/Djy.Common/Extentions/StringExtension.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Runtime.InteropServices;
using System.Security.Cryptography;
using System.Text;
using System.Text.RegularExpressions;
namespace Common
{
  /// <summary>
  ///字符串拓展
  /// </summary>
  public static  class StringExtension
    {

        /// <summary>
        /// 隐藏中间字符串
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static string GetHideCentre(this string str)
        {
            if (str.Length > 8)
            {

                return string.Format("{0}***{1}", str.Substring(0, 4), str.Substring(str.Length - 4, 4));
            }
            else if (str.Length > 5)
            {
                return string.Format("{0}***{1}", str.Substring(0, 2), str.Substring(str.Length - 2, 2));
                
            }
            else if (str.Length > 4)
            {
                return string.Format("{0}***{1}", str.Substring(0, 1), str.Substring(str.Length - 1, 1));

            }
            else
            {
                return GetHideHead(str);
            }
        }


        /// <summary>
        /// 隐藏头部
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static string GetHideHead(this string str)
        {
            var length = 1;
            length = length > str.Length ? str.Length : length;
            if (str.Length < 4)
            {
                length = 1;
                if (str.Length == 1)
                {
                    return str;
                }

                return "**" + str.Substring(str.Length - length, length);
            }
            length = 4;
            return "****" + str.Substring(str.Length - length, length);


        }
        /// <summary>
        /// 根据正则表达式返回符合条件的字符串
        /// </summary>
        /// <param name="str"></param>
        /// <param name="Pattern"></param>
        public static string GetRegex(this string str, string Pattern) {
            var vallist = str.GetRegexList(Pattern);

            return vallist.Count > 0 ? vallist[0] : "";
        }

        /// <summary>
        /// 根据正则表达式返回符合条件的字符串list
        /// </summary>
        /// <param name="str"></param>
        /// <param name="pattern">正则表达式</param>
        /// <param name="Splitstr">字符串分隔符队列默认  , 回车</param>
        /// <returns></returns>
        public static List<string> GetRegexList(this string str, string pattern, List<char> Splitstr =null) {
            var list = new List<string>();
            if (str == null) {
                return list;
            }
            List<char> _Splitstr =new List<char> { ',','\n',' ' };
            if (Splitstr == null)
            {
                Splitstr = _Splitstr;
            }
            else {
                Splitstr.AddRange(_Splitstr);
            }
            try
            {
                var strlist = new List<string>();
                foreach (var spli in Splitstr) {
                    strlist.AddRange(str.Split(spli).ToList());
                }

                strlist.ForEach(item =>
                {

                    foreach (var match in Regex.Matches(item, pattern))
                    {
                        var val = match.ToString();
                        if (list.IndexOf(val) < 0)
                        {
                            list.Add(val);
                        }
                    }
                });

                
            }
            catch { }

            return list;
        }
        /// <summary>
        /// 移除所有空格包含中间的。
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static string TrimAll(this string str) {
           var val= str.Trim().Replace(" ","").Replace(" ","");

            return val;
        }

       
  
        /// <summary>
        /// 用于判断是否为空字符
        /// </summary>
        /// <param name="s"></param>
        /// <returns></returns>
        public static bool  IsNull(this string s)
        {
            return s == null || (s.Trim().Length == 0);
        }
        /// <summary>
        /// 判断是否是guid
        /// </summary>
        /// <param name="s"></param>
        /// <returns></returns>
        public static bool IsGuid(this string s) {
            return Guid.TryParse(s,out var newgid);
        }

        /// <summary>
        /// 用于判断是否为非空字符
        /// </summary>
        /// <param name="s"></param>
        /// <returns></returns>
        public static bool IsNotNull(this string s)
        {
            return !s.IsNull();
        }

        #region 加密算法
        /// <summary>
        /// 将字符串SHA1
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static string ToSHA1(this string str)
        {
            return SafeTools.SHA1(str).ToLower();
        }
        /// <summary>
        /// 将字符串转换成MD5加密字符串
        /// </summary>
        /// <param name="orgStr"></param>
        /// <returns></returns>
        public static string ToMd5(this string orgStr)
        {
            using (var md5 = MD5.Create())
            {
                var encoding = Encoding.UTF8;
                var encryptedBytes = md5.ComputeHash(encoding.GetBytes(orgStr));
                var sb = new StringBuilder(32);
                foreach (var bt in encryptedBytes)
                {
                    sb.Append(bt.ToString("x").PadLeft(2, '0'));
                }
                return sb.ToString().ToLower();
            }
        }
        #endregion
        /// <summary>
        /// 获取扩展名
        /// </summary>
        /// <param name="s"></param>
        /// <returns></returns>
        public static string GetExt(this string s)
        {
            var ret = string.Empty;
            if (!s.Contains('.')) return ret;
            var temp = s.Split('.');
            ret = temp[temp.Length - 1];

            return ret;
        }
        /// <summary>
        /// 验证QQ格式
        /// </summary>
        /// <param name="s"></param>
        /// <returns></returns>
        public static bool IsQq(this string s)
        {
            return s.IsNull() || Regex.IsMatch(s, @"^[1-9]\d{4,15}$");
        }

        /// <summary>
        /// 将字符串根据分隔符转换我List<string>
        /// </summary>
        /// <param name="str"></param>
        /// <param name="split">分隔符</param>
        /// <returns></returns>
        public static List<string> ToListString(this string str, char split)
        {
            return new List<string>(str.Split(split));
           
        }

        /// <summary>
        /// 判断是否为有效的Email地址
        /// </summary>
        /// <param name="s"></param>
        /// <returns></returns>
        public static bool IsEmail(this string s)
        {
            if (!s.IsNull())
            {
                //return Regex.IsMatch(s,
                //         @"^(?("")("".+?""@)|(([0-9a-zA-Z]((\.(?!\.))|[-!#\$%&'\*\+/=\?\^`\{\}\|~\w])*)(?<=[0-9a-zA-Z])@))" +
                //         @"(?(\[)(\[(\d{1,3}\.){3}\d{1,3}\])|(([0-9a-zA-Z][-\w]*[0-9a-zA-Z]\.)+[a-zA-Z]{2,6}))$");
                const string pattern = @"^[\w-]+(\.[\w-]+)*@[\w-]+(\.[\w-]+)+$";
                return Regex.IsMatch(s, pattern);
            }
            return false;
        }
        /// <summary>
        /// 判断是否是url
        /// </summary>
        /// <param name="s"></param>
        /// <returns></returns>
        public static bool IsUrl(this string s) {
            if (!s.IsNull()) {
                const string pattern = @"^(http://|https://)?((?:[A-Za-z0-9]+-[A-Za-z0-9]+|[A-Za-z0-9]+)\.)+([A-Za-z]+)[/\?\:]?.*$";
                return Regex.IsMatch(s,pattern);
            }
            return false;
        }

        /// <summary>
        /// 验证是否是合法的电话号码
        /// </summary>
        /// <param name="s"></param>
        /// <returns></returns>
        public static bool IsPhone(this string s)
        {
            if (!s.IsNull())
            {
                return Regex.IsMatch(s, @"^\+?((\d{2,4}(-)?)|(\(\d{2,4}\)))*(\d{0,16})*$");
            }
            return true;
        }

        /// <summary>
        /// 验证是否是合法的手机号码
        /// </summary>
        /// <param name="s"></param>
        /// <returns></returns>
        public static bool IsMobile(this string s)
        {
            if (!s.IsNull())
            {
                return Regex.IsMatch(s, @"^\w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*$");
            }
            return false;
        }

        /// <summary>
        /// 验证是否是合法的邮编
        /// </summary>
        /// <param name="s"></param>
        /// <returns></returns>
        public static bool IsZipCode(this string s)
        {
            if (!s.IsNull())
            {
                return Regex.IsMatch(s, @"[1-9]\d{5}(?!\d)");
            }
            return true;
        }

        /// <summary>
        /// 验证是否是合法的传真
        /// </summary>
        /// <param name="s"></param>
        /// <returns></returns>
        public static bool IsFax(this string s)
        {
            if (!s.IsNull())
            {
                return Regex.IsMatch(s, @"(^[0-9]{3,4}\-[0-9]{7,8}$)|(^[0-9]{7,8}$)|(^\([0-9]{3,4}\)[0-9]{3,8}$)|(^0{0,1}13[0-9]{9}$)");
            }
            return true;
        }

        /// <summary>
        /// 检查字符串是否为有效的int数字
        /// </summary>
        /// <param name="val"></param>
        /// <returns></returns>
        public static bool Isint(this string val)
        {
            if (IsNull(val))
                return false;
            int k;
            return int.TryParse(val, out k);
        }
        /// <summary>
        /// 检查字符串是否为有效的long数字
        /// </summary>
        /// <param name="val"></param>
        /// <returns></returns>
        public static bool Islong(this string val)
        {
            if (IsNull(val))
                return false;
            long k;
            return long.TryParse(val, out k);
        }
        /// <summary>
        /// 字符串转数字，未转换成功返回0
        /// </summary>
        /// <param name="val"></param>
        /// <returns></returns>
        public static int ToInt(this string val)
        {
            
            if (IsNull(val))
                return 0;
            int k;
            return int.TryParse(val, out k) ? k : 0;
        }
        /// <summary>
        /// 字符串转 浮点Double
        /// </summary>
        /// <param name="val"></param>
        /// <returns></returns>
        public static double ToDouble(this string val) {
            if (IsNull(val)) {
                return 0; 
            }
            double values;
            return double.TryParse(val, out values) ? values : 0;
        }

        /// <summary>
        /// 将int间隔字符串转换为list<int>
        /// </summary>
        /// <param name="str"></param>
        /// <param name="Split"></param>
        /// <returns></returns>
        public static List<int> ToIntList(this string str, char Split=',')
        {
            return str.Split(Split).strToIntArray().ToList();
        }

        /// <summary>
        /// 判断是否是json字符串
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static bool IsJson(this string str) {
            try
            {
                System.Text.Json.JsonSerializer.Deserialize<System.Text.Json.JsonElement>(str);
                return true;
            }
            catch {
                return false;
            }
        }

        /// <summary>
        /// 检查字符串是否为有效的INT64数字
        /// </summary>
        /// <param name="val"></param>
        /// <returns></returns>
        public static bool IsInt64(this string val)
        {
            if (IsNull(val))
                return false;
            long k;
            return long.TryParse(val, out k);
        }

        /// <summary>
        /// 验证是否是身份证
        /// </summary>
        /// <param name="ID"></param>
        /// <returns></returns>
        public static bool IsCardId(this string ID)
        {
            var r = false;
            if (IsNull(ID))
                r= false;
            if (ID.Length == 15)
            {

                var date = $"19{ID.Substring(6, 2)}-{ID.Substring(8, 2)}-{ID.Substring(10, 2)}";
                DateTime dt;
                return DateTime.TryParse(date,out dt);
            }
            else if (ID.Length == 18)
            {
                var date = $"{ID.Substring(6, 4)}-{ID.Substring(10, 2)}-{ID.Substring(12, 2)}";
                DateTime dt;
                return DateTime.TryParse(date, out dt);
            }
            else { r= false; }

            return r;
        }

        /// <summary>
        /// 检查字符串是否为有效的double
        /// </summary>
        /// <param name="val"></param>
        /// <returns></returns>
        public static bool IsDecimal(this string val)
        {
            if (IsNull(val))
                return false;
            double d;
            return double.TryParse(val, out d);
        }

        /// <summary>
        ///检测字符串是否是时间类型
        /// </summary>
        /// <param name="val"></param>
        /// <returns></returns>
        public static bool IsDateTime(this string val) {
            if (IsNull(val))
                return false;
            DateTime d;
            return DateTime.TryParse(val,out d);
        }

        /// <summary>
        /// 将时间字符串转为指定格式的字符串  自动判断是否是时间格式，如果不是时间格式则返回原有字符串
        /// </summary>
        /// <param name="val"></param>
        /// <param name="Format"></param>
        /// <returns></returns>
        public static string GetDateTimeFormat(this string val,string Format= "yyyy-MM-dd") {
            if (Format.IsNull())
            {
                Format = "yyyy-MM-dd";
            }

            return val.IsDateTime() ? ((DateTime)val.ToDateTime()).ToString(Format) : val;
        }
        /// <summary>
        /// 获取字符串内包换的数字行字符串
        /// </summary>
        /// <param name="val"></param>
        /// <param name="defaultstr">为空的时候返回的默认字符串</param>
        /// <returns></returns>
        public static string GetIncludeNumber(this string val,string defaultstr="0") {
            if (val.IsNull())
            {
                return defaultstr;
            }
            var str = val.GetRegex("[0-9]{1,100}");
            if (str.IsNull()) {
                str = defaultstr;
            }

            return str;
        }

        /// <summary>
        /// 字符串转时间 非时间返回空
        /// </summary>
        /// <param name="val"></param>
        /// <returns></returns>
        public static DateTime? ToDateTime(this string val) {
            if (val.IsDateTime())
            {
                return DateTime.Parse(val);
            }
            else {
                return null;
            }
        }
        /// <summary>
        /// 将时间类型字符转时间戳 入股不是时间类型则返回0
        /// </summary>
        /// <param name="Val"></param>
        /// <returns></returns>
        public static long ToTimestamp(this string Val) {
            var time = Val.ToDateTime();
            return time != null ? ((DateTime)time).ToTimeStamp() : 0;
        }

        /// <summary>
        /// 从左边截取N个字符
        /// </summary>
        /// <param name="val"></param>
        /// <returns></returns>
        public static string GetLeftStr(this string val,int count=0)
        {
            if (count > val.Length)
                return null;

            return val.Substring(0,count);
        }
        /// <summary>
        /// 获取一个字符串在另外一个字符串出现的次数
        /// </summary>
        /// <returns></returns>
        public static int GetincludeCount(this string str,string indexstr) {
            var val = str.Replace(indexstr,null);

            return (str.Length - val.Length) / indexstr.Length;
        }

        /// <summary>
        ///从右边截取N个字符
        /// </summary>
        /// <param name="val"></param>
        /// <param name="count"></param>
        /// <returns></returns>
        public static string GetRightStr(this string val, int count=0)
        {

            if (count > val.Length)
                return null;

            return val.Substring(val.Length-count, count);

        }
        /// <summary>
        /// 索引字符串是否以指定列表中的字符串开头
        /// </summary>
        /// <param name="val"></param>
        /// <param name="List"></param>
        /// <returns></returns>
        public static bool IndexStartWithList(this string val, List<string> List) {
            var r = false;
            foreach (var item in List) {
                if (val.StartsWith(item))
                {
                    r=true;
                    break;
                }
            }

            return r;
        }

        /// <summary>
        /// 将Base64 解析解出 如果失败则返回null
        /// </summary>
        /// <param name="val"></param>
        /// <returns></returns>
        public static string Base64ToString(this string val)
        { string r = null;
            try
            {
                r = Encoding.UTF8.GetString(Convert.FromBase64String(val));
            }
            catch { }

            return r;
        }
        /// <summary>
        /// 判断是否是Base64
        /// </summary>
        /// <param name="val"></param>
        /// <returns></returns>
        public static bool IsBase64(this string val)
        {
            bool r = false;
            try
            {
               var getr= Encoding.UTF8.GetString(Convert.FromBase64String(val));
                r = true;
            }
            catch { r = false; }

            return r;
        }
        /// <summary>
        /// 字符转换为base64 错误或空字符串返回 null
        /// </summary>
        /// <param name="val"></param>
        /// <returns></returns>
        public static string ToBase64(this string val)
        {
            string str = null;
            if (val.IsNull())
                return null;
            try {
               
                str = Convert.ToBase64String(Encoding.UTF8.GetBytes(val));
            }
            catch {
                str = null;
            }

            return str;
        }

        /// <summary>
        /// 获取字符串中的数字字符串
        /// </summary>
        /// <returns></returns>
        public static string GetIntStr(this string val)
        {
            var r = "";
            var clist = new List<char>() {'0','1','2','3','4','5','6','7','8','9' };
            foreach (var v in val)
            {
                if (clist.IndexOf(v) >= 0)
                { 
                    r+=v;
                }
            }
            return r;
        }
        public static bool _windows = RuntimeInformation.IsOSPlatform(OSPlatform.Windows);
        /// <summary>
        /// 自动调整windows/linux下面文件目录斜杠的处理
        /// </summary>
        /// <param name="path"></param>
        /// <returns></returns>
        public static string ReplacePath(this string path)
        {
            if (string.IsNullOrEmpty(path))
                return "";
            if (_windows)
                return path.Replace("/", "\\");
            return path.Replace("\\", "/");

        }
        public static bool IsInt(this object obj)
        {
            if (obj == null)
                return false;
            bool reslut = Int32.TryParse(obj.ToString(), out int _number);
            return reslut;

        }
        public static bool IsDate(this object str)
        {
            return IsDate(str, out _);
        }
        public static bool IsDate(this object str, out DateTime dateTime)
        {
            dateTime = DateTimeExtension.GetUtcDateTime();
            if (str == null || str.ToString() == "")
            {
                return false;
            }
            return DateTime.TryParse(str.ToString(), out dateTime);
        }
        /**/
        /// <summary>
        /// 判断一个字符串是否为合法数字(指定整数位数和小数位数)
        /// </summary>
        /// <param name="str">字符串</param>
        /// <param name="precision">整数位数</param>
        /// <param name="scale">小数位数</param>
        /// <returns></returns>
        public static bool IsNumber(this string str, int precision, int scale)
        {
            if ((precision == 0) && (scale == 0))
            {
                return false;
            }
            string pattern = @"(^\d{1," + precision + "}";
            if (scale > 0)
            {
                pattern += @"\.\d{0," + scale + "}$)|" + pattern;
            }
            pattern += "$)";
            return Regex.IsMatch(str, pattern);
        }
        /// <summary>
        /// 根据传入格式判断是否为小数
        /// </summary>
        /// <param name="str"></param>
        /// <param name="formatString">18,5</param>
        /// <returns></returns>
        public static bool IsNumber(this string str, string formatString)
        {
            if (string.IsNullOrEmpty(str))
                return false;
            int precision = 32;
            int scale = 5;
            try
            {
                if (string.IsNullOrEmpty(formatString))
                {
                    precision = 10;
                    scale = 2;
                }
                else
                {
                    string[] numbers = formatString.Split(',');
                    precision = Convert.ToInt32(numbers[0]);
                    scale = numbers.Length == 0 ? 2 : Convert.ToInt32(numbers[1]);
                }
            }
            catch { };
            return IsNumber(str, precision, scale);
        }

        public static bool IsNullOrEmpty(this object str)
        {
            if (str == null)
                return true;
            return str.ToString() == "";
        }


        public static int GetInt(this object obj)
        {
            if (obj == null)
                return 0;
            int.TryParse(obj.ToString(), out int _number);
            return _number;

        } /// <summary>
          /// 获取 object 中的枚举值
          /// </summary>
          /// <param name="str"></param>
          /// <returns></returns>
          /// <remarks></remarks>
        public static long GetLong(this object obj)
        {
            if (obj == null)
                return 0;

            try
            {
                return Convert.ToInt64(Convert.ToDouble(obj));
            }
            catch
            {
                return 0;
            }
        }

        /// <summary>
        /// 获取 object 中的 float
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>

        public static float GetFloat(this object obj)
        {
            if (System.DBNull.Value.Equals(obj) || null == obj)
                return 0;

            try
            {
                return float.Parse(obj.ToString());
            }
            catch
            {
                return 0;
            }
        }
        public static double GetDouble(this object obj)
        {
            if (System.DBNull.Value.Equals(obj) || null == obj)
                return 0;

            try
            {
                return Convert.ToDouble(obj);
            }
            catch
            {
                return 0;
            }
        }
        /// <summary>
        /// 获取 object 中的 decimal
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        /// <remarks></remarks>
        public static decimal GetDecimal(this object obj)
        {
            if (System.DBNull.Value.Equals(obj) || null == obj)
                return 0;

            try
            {
                return Convert.ToDecimal(obj);
            }
            catch
            {
                return 0;
            }
        } /// <summary>
          /// 获取 object 中的 decimal
          /// </summary>
          /// <param name="str"></param>
          /// <returns></returns>
          /// <remarks></remarks>
        
        public static DateTime? GetDateTime(this object obj)
        {
            if (System.DBNull.Value.Equals(obj) || null == obj)
                return null;
            bool result = DateTime.TryParse(obj.ToString(), out DateTime dateTime);
            if (!result)
                return null;
            return dateTime;
        }
        public static object ParseTo(this string str, string type)
        {
            switch (type)
            {
                case "System.Boolean":
                    return ToBoolean(str);
                case "System.SByte":
                    return ToSByte(str);
                case "System.Byte":
                    return ToByte(str);
                case "System.UInt16":
                    return ToUInt16(str);
                case "System.Int16":
                    return ToInt16(str);
                case "System.uInt32":
                    return ToUInt32(str);
                case "System.Int32":
                    return ToInt32(str);
                case "System.UInt64":
                    return ToUInt64(str);
                case "System.Int64":
                    return ToInt64(str);
                case "System.Single":
                    return ToSingle(str);
                case "System.Double":
                    return ToDouble(str);
                case "System.Decimal":
                    return ToDecimal(str);
                case "System.DateTime":
                    return ToDateTime(str);
                case "System.Guid":
                    return ToGuid(str);
            }
            throw new NotSupportedException(string.Format("The string of \"{0}\" can not be parsed to {1}", str, type));
        }

        public static sbyte? ToSByte(this string value)
        {
            sbyte value2;
            if (sbyte.TryParse(value, out value2))
            {
                return value2;
            }
            return null;
        }

        public static byte? ToByte(this string value)
        {
            byte value2;
            if (byte.TryParse(value, out value2))
            {
                return value2;
            }
            return null;
        }

        public static ushort? ToUInt16(this string value)
        {
            ushort value2;
            if (ushort.TryParse(value, out value2))
            {
                return value2;
            }
            return null;
        }

        public static short? ToInt16(this string value)
        {
            if (short.TryParse(value, out short value2))
            {
                return value2;
            }
            return null;
        }

        public static uint? ToUInt32(this string value)
        {
            uint value2;
            if (uint.TryParse(value, out value2))
            {
                return value2;
            }
            return null;
        }

        public static ulong? ToUInt64(this string value)
        {
            ulong value2;
            if (ulong.TryParse(value, out value2))
            {
                return value2;
            }
            return null;
        }

        public static long? ToInt64(this string value)
        {
            long value2;
            if (long.TryParse(value, out value2))
            {
                return value2;
            }
            return null;
        }

        public static float? ToSingle(this string value)
        {
            float value2;
            if (float.TryParse(value, out value2))
            {
                return value2;
            }
            return null;
        }
 
        public static decimal? ToDecimal(this string value)
        {
            decimal value2;
            if (decimal.TryParse(value, out value2))
            {
                return value2;
            }
            return null;
        }

        public static bool? ToBoolean(this string value)
        {
            bool value2;
            if (bool.TryParse(value, out value2))
            {
                return value2;
            }
            return null;
        }



        public static Guid? ToGuid(this string str)
        {
            Guid value;
            if (Guid.TryParse(str, out value))
            {
                return value;
            }
            return null;
        }

        
        public static int? ToInt32(this string input)
        {
            if (string.IsNullOrEmpty(input))
            {
                return null;
            }
            int value;
            if (int.TryParse(input, out value))
            {
                return value;
            }
            return null;
        }

        /// <summary>
        /// 将字符串分隔成list
        /// </summary>
        /// <param name="value"></param>
        /// <param name="strSplit"></param>
        /// <returns></returns>
        public static List<string> StringToList(string value, string strSplit)
        {
            List<string> lst = new List<string>();
            if (string.IsNullOrEmpty(value))
                return lst;
            else if (value.IndexOf(strSplit) == -1)
                return new List<string>() { value };
            lst = new List<string>(value.Split(new string[] { strSplit }, StringSplitOptions.RemoveEmptyEntries));
            return lst;
        }

        /// <summary>
        ///     替换空格字符
        /// </summary>
        /// <param name="input"></param>
        /// <param name="replacement">替换为该字符</param>
        /// <returns>替换后的字符串</returns>
        public static string ReplaceWhitespace(this string input, string replacement = "")
        {
            return string.IsNullOrEmpty(input) ? null : Regex.Replace(input, "\\s", replacement, RegexOptions.Compiled);
        }

        private static char[] randomConstant ={
        '0','1','2','3','4','5','6','7','8','9',
        'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z',
        'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z'
      };
        /// <summary>
        /// 生成指定长度的随机数
        /// </summary>
        /// <param name="length"></param>
        /// <returns></returns>
        public static string GenerateRandomNumber(this int length)
        {
            System.Text.StringBuilder newRandom = new System.Text.StringBuilder(62);
            Random rd = new Random();
            for (int i = 0; i < length; i++)
            {
                newRandom.Append(randomConstant[rd.Next(62)]);
            }
            return newRandom.ToString();
        }
        public static string MaxSubstring(this string origin, int maxLength)
        {
            return origin.Length >= maxLength ? origin.Substring(0, maxLength) : origin;
        }
 
        public static string SafeTrim(this string s)
        {
            if (string.IsNullOrEmpty(s))
            {
                //return string.Empty;
                return null;
            }

            return s.Trim();
        }
        /// <summary>
        /// 超过长度自动加省略号
        /// </summary>
        /// <param name="source"></param>
        /// <param name="num">字节数</param>
        /// <param name="isDoubleByte">是否双字节</param>
        /// <returns></returns>
        public static string Ellipsis(this string source, int num, bool isDoubleByte = true)
        {
            if (isDoubleByte)
            {
                num = 2 * num;
            }
            if (string.IsNullOrWhiteSpace(source))
            {
                return string.Empty;
            }

            int len = Encoding.Default.GetBytes(source).Length;
            if (len <= num)
            {
                return source;
            }

            int curNum = 0;
            int curLen = 0;
            foreach (var item in source)
            {
                curNum += Encoding.Default.GetBytes(item.ToString()).Length;
                if (curNum > num)
                {
                    break;
                }
                curLen++;
            }
            return source.Substring(0, curLen) + "...";
        }

        public static string TrimAllEmpty(this string source)
        {
            if (string.IsNullOrWhiteSpace(source))
            {
                return string.Empty;
            }
            Regex replaceSpace = new Regex(@"\s{1,}", RegexOptions.IgnoreCase);
            return replaceSpace.Replace(source, string.Empty).Trim();
        }
        public static string GetNeedString(this string s, string reg)
        {

            Regex r = new Regex(@reg, RegexOptions.IgnoreCase);
            return r.Replace(s, string.Empty);

        }
        
        
        /// <summary>
        /// 去除SQL特殊字符
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static string ReplaceSQLChar(this string str)
        {
            if (string.IsNullOrEmpty(str))
                return String.Empty;
            str = str.Replace("'", "");
            str = str.Replace(";", "");
            str = str.Replace(",", "");
            str = str.Replace("?", "");
            str = str.Replace("<", "");
            str = str.Replace(">", "");
            str = str.Replace("(", "");
            str = str.Replace(")", "");
            str = str.Replace("@", "");
            str = str.Replace("=", "");
            str = str.Replace("+", "");
            str = str.Replace("*", "");
            str = str.Replace("&", "");
            str = str.Replace("#", "");
            str = str.Replace("%", "");
            str = str.Replace("$", "");

            //删除与数据库相关的词
            str = Regex.Replace(str, "select", "", RegexOptions.IgnoreCase);
            str = Regex.Replace(str, "insert", "", RegexOptions.IgnoreCase);
            str = Regex.Replace(str, "delete from", "", RegexOptions.IgnoreCase);
            str = Regex.Replace(str, "count", "", RegexOptions.IgnoreCase);
            str = Regex.Replace(str, "drop table", "", RegexOptions.IgnoreCase);
            str = Regex.Replace(str, "truncate", "", RegexOptions.IgnoreCase);
            str = Regex.Replace(str, "asc", "", RegexOptions.IgnoreCase);
            str = Regex.Replace(str, "mid", "", RegexOptions.IgnoreCase);
            str = Regex.Replace(str, "char", "", RegexOptions.IgnoreCase);
            str = Regex.Replace(str, "xp_cmdshell", "", RegexOptions.IgnoreCase);
            str = Regex.Replace(str, "exec master", "", RegexOptions.IgnoreCase);
            str = Regex.Replace(str, "net localgroup administrators", "", RegexOptions.IgnoreCase);
            str = Regex.Replace(str, "and", "", RegexOptions.IgnoreCase);
            str = Regex.Replace(str, "net user", "", RegexOptions.IgnoreCase);
            str = Regex.Replace(str, "or", "", RegexOptions.IgnoreCase);
            str = Regex.Replace(str, "net", "", RegexOptions.IgnoreCase);
            str = Regex.Replace(str, "--", "", RegexOptions.IgnoreCase);
            str = Regex.Replace(str, "delete", "", RegexOptions.IgnoreCase);
            str = Regex.Replace(str, "drop", "", RegexOptions.IgnoreCase);
            str = Regex.Replace(str, "script", "", RegexOptions.IgnoreCase);
            str = Regex.Replace(str, "update", "", RegexOptions.IgnoreCase);
            str = Regex.Replace(str, "and", "", RegexOptions.IgnoreCase);
            str = Regex.Replace(str, "chr", "", RegexOptions.IgnoreCase);
            str = Regex.Replace(str, "master", "", RegexOptions.IgnoreCase);
            str = Regex.Replace(str, "truncate", "", RegexOptions.IgnoreCase);
            str = Regex.Replace(str, "declare", "", RegexOptions.IgnoreCase);
            str = Regex.Replace(str, "mid", "", RegexOptions.IgnoreCase);

            return str;
        }
    }
}