C# · 12月 21, 2021

C#纯数学方法递归实现货币数字转换中文

最近由于项目的原因,需要写一个货币数字转换中文的算法,先在网了找了一下,结果发现无一列外都是用(Replace)替换的方式来实现的,所以想写个另外的算法;因为本人是学数学出身的,所以用纯数学的方法实现。

  注意:本文中的算法支持小于1023 (也就是9999亿兆)货币数字转化。

  货币中文说明: 在说明代码之前,首先让我们回顾一下货币的读法。

  10020002.23  读为 壹仟零贰万零贰元贰角叁分  1020         读为 壹仟零贰拾元整。  100000       读为 拾万元整  0.13         读为 壹角叁分

 

  代码:

测试工程  static void Main(string[] args){

Console.WriteLine(“请输入金额”);string inputNum = Console.ReadLine();while (inputNum != “exit”){

//货币数字转化类NumCast nc = new NumCast();

if (nc.IsValidated(inputNum)){try{string chineseCharacter = nc.Converttochinese(inputNum);Console.WriteLine(chineseCharacter);}catch (Exception er){Console.WriteLine(er.Message);}}else{Console.WriteLine(“不合法的数字或格式”);}

Console.WriteLine(“\n请输入金额”);inputNum = Console.ReadLine();

}Console.ReadLine();}

测试结果如下:

货币转化类(NumCast类)功能介绍

1 常量的规定 /// /// 数位/// public enum NumLevel { Cent,Chiao,Yuan,Ten,Hundred,Thousand,TenThousand,hundredMillon,Trillion };

/// /// 数位的指数/// private int[] NumLevelExponent = new int[] { -2,-1,1,2,3,4,8,12 };

/// /// 数位的中文字符/// private string[] NumLeverChineseSign = new string[] { “分”,”角”,”元”,”拾”,”佰”,”仟”,”万”,”亿”,”兆” };

/// /// 大写字符/// private string[] NumChineseCharacter = new string[] {“零”,”壹”,”贰”,”叁”,”肆”,”伍”,”陆”,”柒”,”捌”,”玖”};

/// /// 整(当没有 角分 时)///

private const string EndOfInt = “整”;

2:数字合法性验证,采用正则表达式验证 /// /// 正则表达验证数字是否合法/// /// <param name="Num">/// public bool IsValidated(T Num){Regex reg = new Regex(@"^(([0])|([1-9]\d{0,23}))(\.\d{1,2})?$");if (reg.IsMatch(Num.ToString())){return true;

}return false;}

3: 获取数位 例如 1000的数位为 NumLevel.Thousand

/// /// 获取数字的数位 使用log/// /// 0){numLevelLength = Math.Floor(Math.Log10(Num));for (int i = NumLevelExponent.Length – 1; i >= 0; i–){if (numLevelLength >= NumLevelExponent[i]){NLvl = (NumLevel)i;break;}}}else{NLvl = NumLevel.Yuan;}return NLvl;

}

4:判断数字之间是否有跳位,也就是中文中间是否要加零,例如1020 就应该加零。 /// /// 是否跳位/// /// private bool IsDumpLevel(double Num){ if (Num > 0){NumLevel? currentLevel = GetNumLevel(Num);NumLevel? nextLevel = null;int numExponent = this.NumLevelExponent[(int)currentLevel];

double postfixNun = Math.Round(Num % (Math.Pow(10,numExponent)),2);if(postfixNun> 0)nextLevel = GetNumLevel(postfixNun);if (currentLevel != null && nextLevel != null){if (currentLevel > nextLevel + 1){return true;}}}return false;

}

5 把长数字分割为两个较小的数字数组,例如把9999亿兆,分割为9999亿和0兆,

因为计算机不支持过长的数字。 /// /// 是否大于兆,如果大于就把字符串分为两部分,/// 一部分是兆以前的数字/// 另一部分是兆以后的数字/// /// NumLevelExponent[(int)NumLevel.Trillion]){isBig = true;}}else{//如果大于兆if (Num.Length > NumLevelExponent[(int)NumLevel.Trillion]){isBig = true;}}return isBig;}

/// /// 把数字字符串由‘兆’分开两个/// /// private double[] SplitNum(string Num){//兆的开始位double[] TillionLevelNums = new double[2];int trillionLevelLength;if (Num.IndexOf(‘.’) == -1)trillionLevelLength = Num.Length – NumLevelExponent[(int)NumLevel.Trillion];elsetrillionLevelLength = Num.IndexOf(‘.’) – NumLevelExponent[(int)NumLevel.Trillion];//兆以上的数字TillionLevelNums[0] = Convert.ToDouble(Num.Substring(0,trillionLevelLength));//兆以下的数字TillionLevelNums[1] = Convert.ToDouble(Num.Substring(trillionLevelLength ));return TillionLevelNums;}

6 是否以“壹拾”开头,如果是就可以把它变为“拾”  bool isStartOfTen = false;while (Num >=10){if (Num == 10){isStartOfTen = true;break;}//Num的数位NumLevel currentLevel = GetNumLevel(Num);

int numExponent = this.NumLevelExponent[(int)currentLevel];Num = Convert.ToInt32(Math.Floor(Num / Math.Pow(10,numExponent)));if (currentLevel == NumLevel.Ten && Num == 1){isStartOfTen = true;break;}}return isStartOfTen;

7 合并大于兆连个数组转化成的货币字符串

/// /// 合并分开的数组中文货币字符/// /// <param name="tillionNums">/// private string ContactNumChinese(double[] tillionNums){string uptillionStr = CalculateChineseSign(tillionNums[0],NumLevel.Trillion,true,IsStartOfTen(tillionNums[0]));string downtrillionStr = CalculateChineseSign(tillionNums[1],null,false);string chineseCharactor = string.Empty;//分开后的字符是否有跳位if (GetNumLevel(tillionNums[1] * 10) == NumLevel.Trillion){chineseCharactor = uptillionStr + NumLeverChineseSign[(int)NumLevel.Trillion] + downtrillionStr;}else{chineseCharactor = uptillionStr + NumLeverChineseSign[(int)NumLevel.Trillion];if (downtrillionStr != "零元整"){chineseCharactor += NumChineseCharacter[0] + downtrillionStr;}else{chineseCharactor += "元整";}}return chineseCharactor;

}

8:递归计算货币数字的中文 /// /// 计算中文字符串/// /// <param name="Num">数字/// <param name="NL">数位级别 比如1000万的 数位级别为万/// <param name="IsExceptTen">是否以‘壹拾’开头/// 中文大写public string CalculateChineseSign(double Num,NumLevel? NL,bool IsDump,bool IsExceptTen){Num = Math.Round(Num,2);bool isDump = false;//Num的数位NumLevel? currentLevel = GetNumLevel(Num);int numExponent = this.NumLevelExponent[(int)currentLevel];

string Result = string.Empty;

//整除后的结果int prefixNum;//余数 当为小数的时候 分子分母各乘100double postfixNun ;if (Num >= 1){prefixNum = Convert.ToInt32(Math.Floor(Num / Math.Pow(10,numExponent)));postfixNun = Math.Round(Num % (Math.Pow(10,2);}else{prefixNum = Convert.ToInt32(Math.Floor(Num*100 / Math.Pow(10,numExponent+2)));postfixNun = Math.Round(Num * 100 % (Math.Pow(10,numExponent + 2)),2);postfixNun *= 0.01;}

if (prefixNum 0){Result += NumLeverChineseSign[(int)NumLevel.Yuan];

}

}else{//当 前缀数字未被除尽时, 递归下去NumLevel? NextNL = null;if ((int)currentLevel >= (int)(NumLevel.TenThousand))NextNL = currentLevel;

Result += CalculateChineseSign((double)prefixNum,NextNL,isDump,IsExceptTen);if ((int)currentLevel >= (int)(NumLevel.TenThousand)){Result += NumLeverChineseSign[(int)currentLevel];}}

//是否跳位// 判断是否加零, 比如302 就要给三百 后面加零,变为 三百零二。if (IsDumpLevel(Num)){Result += NumChineseCharacter[0];isDump = true;

}

//余数是否需要递归if (postfixNun > 0){Result += CalculateChineseSign(postfixNun,NL,false);}else if (postfixNun == 0 && currentLevel > NumLevel.Yuan ){//当数字是以零元结尾的加上 元整 比如1000000一百万元整if (NL == null){Result += NumLeverChineseSign[(int)NumLevel.Yuan];Result += EndOfInt;}}

return Result;}

9:外部调用的转换方法。

 /// /// 外部调用的转换方法/// /// <param name="Num">/// public string Converttochinese(string Num){

if (!IsValidated(Num)){throw new OverflowException(“数值格式不正确,请输入小于9999亿兆的数字且最多精确的分的金额!”);}string chineseCharactor = string.Empty;if (IsBigThanTillion(Num)){double[] tillionNums = SplitNum(Num);chineseCharactor = ContactNumChinese(tillionNums);}else{double dNum = Convert.ToDouble(Num);chineseCharactor = CalculateChineseSign(dNum,IsStartOfTen(dNum));}return chineseCharactor;}

  小结:

  个人认为程序的灵魂是算法,大到一个系统中的业务逻辑,小到一个货币数字转中文的算法,处处都体现一种逻辑思想。

  是否能把需求抽象成一个好的数学模型,直接关系到程序的实现的复杂度和稳定性。在一些常用功能中想些不一样的算法,对我们开拓思路很有帮助。                                                         本文转载自‘中国IT实验室’