C# 项目扩展类（字符串格式化、数值转换等）

 一些扩展类，实现数值格式化和字符串转换。

    public static class MyExClass
    {
        static readonly string[] NumLetter =
        {
            "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>
        /// 获取下一个识别码
        /// </summary>
        /// <param name="c"></param>
        /// <returns></returns>
        public static string GetNextLetter(string c)
        {
            var x = Array.IndexOf(NumLetter, c) + 1;
            if (x < NumLetter.Length - 1)
                return NumLetter[x];
            return "#";
        }

        #region TrimEx
        /// <summary>
        /// 替换字符串开头的空格、tab字符、换行符和新行(newline)
        /// </summary>
        /// <param name="val"></param>
        /// <returns></returns>
        public static string TrimStartEx(this string val)
        {
            return Regex.Replace(val, @"^s+", "");
        }
        /// <summary>
        /// 替换字符串结尾的空格、tab字符、换行符和新行(newline)
        /// </summary>
        /// <param name="val"></param>
        /// <returns></returns>
        public static string TrimEndEx(this string val)
        {
            return Regex.Replace(val, @"s+$", "");
        }
        /// <summary>
        /// 替换字符串开头和结尾的空格、tab字符、换行符和新行(newline)
        /// </summary>
        /// <param name="val"></param>
        /// <returns></returns>
        public static string TrimStartEndEx(this string val)
        {
            return val.TrimStartEx().TrimEndEx();
        }

        /// <summary>
        /// 替换字符串中的空格、tab字符、换行符和新行(newline)
        /// </summary>
        /// <param name="val"></param>
        /// <returns></returns>
        public static string TrimEx(this string val)
        {
            return Regex.Replace(val, @"s", "");
        }
        /// <summary>
        /// 替换字符串中的换行符和新行(newline)
        /// </summary>
        /// <param name="val"></param>
        /// <returns></returns>
        public static string TrimExRN(this string val)
        {
            if (string.IsNullOrWhiteSpace(val))
                return val;
            return Regex.Replace(val, @"
|
", "");
        }

        #endregion

        /// <summary>
        /// 判断字符串是否符合a-zA-Z0-9开头，只包含a-zA-Z0-9-_
        /// </summary>
        /// <param name="val"></param>
        /// <returns></returns>
        public static bool TestCodeReg(this string val)
        {
            return Regex.Match(val, "^[a-zA-Z0-9]+[a-zA-Z0-9-_]*$").Success;
        }

        #region 数值格式化、金额格式化
        /// <summary>
        /// 字符串转HTML（换行）
        /// </summary>
        /// <param name="val"></param>
        /// <returns></returns>
        public static string ToHtml(this string val)
        {
            return val.Replace("
", "<br />").Replace("
", "<br />");
        }

        /// <summary>
        /// 去除数值尾部多余的0
        /// </summary>
        /// <param name="val"></param>
        /// <returns></returns>
        public static decimal ToDecTrimEnd0(this decimal val)
        {
            string v = string.Format("{0:0.#########;;#}", val);
            return v == "" ? 0M : v.ToDecimal();
        }

        /// <summary>
        /// 日期格式化 yyyy-MM-dd
        /// </summary>
        /// <param name="dt">Datetime?</param>
        /// <returns>string</returns>
        static public string ToDateString(this DateTime? dt)
        {
            return dt.HasValue ? ((DateTime)dt).ToString("yyyy-MM-dd") : "";
        }

        /// <summary>
        /// 日期格式化 yyyy-MM-dd
        /// </summary>
        /// <param name="dt">Datetime?</param>
        /// <returns>string</returns>
        static public string ToDateString(this DateTime dt)
        {
            return dt.ToString("yyyy-MM-dd");
        }

        /// <summary>
        /// 日期格式化 yyyy-MM-dd
        /// </summary>
        /// <param name="dt">string</param>
        /// <returns>string</returns>
        static public string ToDateString(this string val)
        {
            try
            {
                DateTime dt = DateTime.Parse(val);
                return dt.ToString("yyyy-MM-dd");
            }
            catch(Exception ex)
            {
                return val;
            }
        }
        /// <summary>
        /// 日期格式化 yyyy-MM-dd
        /// </summary>
        /// <param name="dt">string</param>
        /// <returns>string</returns>
        static public string ToDateString(this object val)
        {
            try
            {
                var s = val == null ? "" : val.ToString();
                DateTime dt = DateTime.Parse(s);
                return dt.ToString("yyyy-MM-dd");
            }
            catch (Exception ex)
            {
                return "";
            }
        }

        /// <summary>
        /// 金额取整
        /// </summary>
        /// <param name="val">decimal?</param>
        /// <returns>string</returns>
        static public string ToAmtString(this decimal? val)
        {
            if (val.HasValue)
                return Math.Round((decimal)val).ToString();
            else
                return "";
        }

        /// <summary>
        /// 金额格式化
        /// </summary>
        /// <param name="val">string</param>
        /// <param name="i">精度</param>
        /// <returns>string</returns>
        static public string ToAmtString(this decimal? val, int i)
        {
            if (val.HasValue)
                return Math.Round((decimal)val, i).ToString();
            else
                return "";
        }
        /// <summary>
        /// 金额格式化
        /// </summary>
        /// <param name="val">string</param>
        /// <param name="i">精度</param>
        /// <returns>string</returns>
        static public string ToAmtString(this decimal val, int i)
        {
            return Math.Round((decimal)val, i).ToString();
        }

        /// <summary>
        /// 字符串金额取整
        /// </summary>
        /// <param name="val">string</param>
        /// <returns>string</returns>
        static public string ToAmtString(this string val)
        {
            return StrToAmtString(val, 0);
        }

        /// <summary>
        /// 字符串金额取2位精度
        /// </summary>
        /// <param name="val">string</param>
        /// <returns>string</returns>
        static public string ToAmtString2(this string val)
        {
            return StrToAmtString(val, 2);
        }


        /// <summary>
        /// 字符串金额取3位精度
        /// </summary>
        /// <param name="val">string</param>
        /// <returns>string</returns>
        static public string ToAmtString3(this string val)
        {
            return StrToAmtString(val, 3);
        }


        /// <summary>
        /// 字符串金额取4位精度
        /// </summary>
        /// <param name="val">string</param>
        /// <returns>string</returns>
        static public string ToAmtString4(this string val)
        {
            return StrToAmtString(val, 4);
        }

        /// <summary>
        /// 金额精度格式化
        /// </summary>
        /// <param name="val">string</param>
        /// <param name="i">int32</param>
        /// <returns>string</returns>
        static public string StrToAmtString(string val, Int32 i)
        {
            try
            {
                if (val == "")
                    return "";
                decimal dval = decimal.Parse(val);
                if (dval == 0m)
                    return "";
                dval = Math.Round(dval, i);
                return dval.ToString();
            }
            catch (Exception ex)
            {
                return val;
            }
        }

        /// <summary>
        /// object转金额
        /// </summary>
        /// <param name="val"></param>
        /// <returns></returns>
        static public decimal ToDecimal(this object val)
        {
            decimal d;
            if (val == null) return 0M;
            return decimal.TryParse(val.ToString().Trim(), out d) ? d : 0M;
        }

        /// <summary>
        /// object转金额
        /// </summary>
        /// <param name="val">object</param>
        /// <param name="x">精度</param>
        /// <returns></returns>
        static public decimal ToDecimal(this object val,int x)
        {
            decimal d = val.ToDecimal();
            //d= decimal.TryParse(val.ToString().Trim(), out d) ? d : 0M;
            return Math.Round(d, x);
        }


        /// <summary>
        /// 字符串转金额
        /// </summary>
        /// <param name="val"></param>
        /// <returns></returns>
        static public decimal ToDecimal(this string val)
        {
            decimal d;
            if (decimal.TryParse(val, out d))
                return d;
            else
                return 0M;
        }

        /// <summary>
        /// 字符串转金额
        /// </summary>
        /// <param name="val"></param>
        /// <returns></returns>
        static public decimal? ToDecimalOrNull(this string val)
        {
            decimal d;
            if (decimal.TryParse(val, out d))
                return d;
            else
                return null;
        }
        
        /// <summary>
        /// 字符串转金额
        /// </summary>
        /// <param name="val"></param>
        /// <returns></returns>
        static public decimal ToDecimal(this string val,int i)
        {
            decimal d;
            if (decimal.TryParse(val, out d))
            {
                d = Math.Round(d, i);
                return d;
            }
            else
                return 0M;
        }

        /// <summary>
        /// 字符转整数
        /// </summary>
        /// <param name="val"></param>
        /// <returns></returns>
        static public int ToInt(this string val)
        {
            int i = 0;
            if (!string.IsNullOrWhiteSpace(val))
                int.TryParse(val, out i);
            return i;
        }

        /// <summary>
        /// object转Int
        /// </summary>
        /// <param name="val"></param>
        /// <returns></returns>
        public static int ToInt(this object val)
        {
            if (val == null)
                return 0;
            string v = val.ToString().Trim();
            int i;
            int.TryParse(v, out i);
            return i;
        }

        #endregion

        #region 全角半角转换
        /// <summary>
        /// 转全角的函数(SBC case)
        /// </summary>
        /// <param name="input">任意字符串</param>
        /// <returns>全角字符串</returns>
        ///<remarks>
        ///全角空格为12288，半角空格为32
        ///其他字符半角(33-126)与全角(65281-65374)的对应关系是：均相差65248
        ///</remarks>
        public static string ToSbc(this string input)
        {
            //半角转全角：
            char[] c = input.ToCharArray();
            for (int i = 0; i < c.Length; i++)
            {
                if (c[i] == 32)
                {
                    c[i] = (char)12288;
                    continue;
                }
                if (c[i] < 127)
                    c[i] = (char)(c[i] + 65248);
            }
            return new string(c);
        }
        /// <summary> 转半角的函数(DBC case) </summary>
        /// <param name="input">任意字符串</param>
        /// <returns>半角字符串</returns>
        ///<remarks>
        ///全角空格为12288，半角空格为32
        ///其他字符半角(33-126)与全角(65281-65374)的对应关系是：均相差65248
        ///</remarks>
        public static string ToDbc(this string input)
        {
            char[] c = input.ToCharArray();
            for (int i = 0; i < c.Length; i++)
            {
                if (c[i] == 12288)
                {
                    c[i] = (char)32;
                    continue;
                }
                if (c[i] > 65280 && c[i] < 65375)
                    c[i] = (char)(c[i] - 65248);
            }
            return new string(c);
        }
        #endregion


        #region 燃气系统判断是否门店、气库

        /// <summary>
        /// 是否门店
        /// </summary>
        /// <param name="val"></param>
        /// <returns></returns>
        public static bool IsSalesRoom(this string val)
        {
            var r = Config.GetValue("RSalesRoom");
            return Regex.Match(val, r).Success;
        }

        /// <summary>
        /// 是否气库
        /// </summary>
        /// <param name="val"></param>
        /// <returns></returns>
        public static bool IsGasStation(this string val)
        {
            var r = Config.GetValue("RGasStation");
            return Regex.Match(val, r).Success;
        }
        /// <summary>
        /// 是否座席
        /// </summary>
        /// <param name="val"></param>
        /// <returns></returns>
        public static bool IsAgent(this string val)
        {
            var r = Config.GetValue("RAgent");
            return Regex.Match(val, r).Success;
        }
        /// <summary>
        /// 是否片区负责人
        /// </summary>
        /// <param name="val"></param>
        /// <returns></returns>
        public static bool IsAreaManager(this string val)
        {
            var r = Config.GetValue("RAreaManager");
            return Regex.Match(val, r).Success;
        }

        #endregion
    }