人民币大写金额转换C#方法

方法的代码如下：

 /// <summary>
 /// 人民币大写
 /// </summary>
 /// <param name="input">待转换输入</param>
 /// <param name="prefix">需要添加人民币前缀</param>
 /// <exception cref="ArgumentException" />
 /// <returns>转换后的结果</returns>
 public static string ToCapital(this string input, bool prefix = false) {

     #region Step1 输入有效性验证

     if (!Regex.IsMatch(input, @"(?<=-|^)\d*\.?\d*$"))
         throw new ArgumentException("错误的输入金额！");

     if (Regex.IsMatch(input, @"^\d{25,}"))
         throw new ArgumentException("输入数据太大无法转换！");

     #endregion

     #region Step2 格式化为中间字符串

     var positionDic = new Dictionary<int, string> {
         {,"F"},{,"J"},{,"."},{,"S"},{,"B"},{,"Q"},{,"W"},{,"SW"},{,"BW"},{,"QW"},
         {,"Y"},{,"SY"},{,"BY"},{,"QY"},{,"WY"},{,"SWY"},{,"BWY"},{,"QWY"},{,"YY"},
         {,"SYY"},{,"BYY"},{,"QYY"},{,"WYY"},{,"SWYY"},{,"BWYY"},{,"QWYY"}
     };

     input = Regex.Replace(input, @"^\.", "0.");

     var integerPart = Regex.Replace(input, @"^-|\..*$", "");
     var _matchDecimal = Regex.Match(input, @"\.\d*$", RegexOptions.None);
     var decimalPart = Regex.Replace(_matchDecimal.Success ? Convert.ToDouble(_matchDecimal.Value).ToString("0.00") : "", @"0\.", "");

     var processStack = new Stack<string>();
     var charsArray = (integerPart + decimalPart).Reverse<char>();
     for (int i = ; i < charsArray.Count(); i++) {
         processStack.Push(string.Format("{0}{1}", charsArray.ElementAt(i), positionDic[i]));
     }

     //符号处理 keleyi.com
     if (Regex.IsMatch(input, "^-", RegexOptions.None)) {
         processStack.Push("-");
     }
     if (prefix) {
         processStack.Push("￥");
     }

     var process = string.Empty;
     while (processStack.Count > ) {
         process += processStack.Pop();
     }
     //语义处理模式队列
     Queue<Tuple<string, string, MatchEvaluator>> patterns = new Queue<Tuple<string, string, MatchEvaluator>>();
     var patternBuilder = new StringBuilder();
     for (int i = ; i < positionDic.Count; i++) {
         patternBuilder.AppendFormat("{0}{1}", (i ==  ? "(0(?:" : "") + positionDic[i], i == positionDic.Count -  ? ")+?)+" : "|");
     }
     patterns.Enqueue(Tuple.Create<string, string, MatchEvaluator>(patternBuilder.ToString(), "", null));
     patterns.Enqueue(Tuple.Create<string, string, MatchEvaluator>(@"(?:\d+(?:QW|BW|SW|W|Q|B|S)?\d?YY)+", null, m => m.Value.Replace("YY", "") + "YY"));
     patterns.Enqueue(Tuple.Create<string, string, MatchEvaluator>(@"(?:\d+(?:QW|BW|SW|W|Q|B|S)?\d?Y)+", null, m => m.Value.Replace("Y", "") + "Y"));
     patterns.Enqueue(Tuple.Create<string, string, MatchEvaluator>(@"(?:\d+(?:Q|B|S)?\d?W)+", null, m => m.Value.Replace("W", "") + "W"));
     patterns.Enqueue(Tuple.Create<string, string, MatchEvaluator>(@"(?!^)0+\.", ".", null));
     patterns.Enqueue(Tuple.Create<string, string, MatchEvaluator>(@"^0\.0J|^0\.", "", null));
     patterns.Enqueue(Tuple.Create<string, string, MatchEvaluator>("0J|0F", "", null));
     patterns.Enqueue(Tuple.Create<string, string, MatchEvaluator>("J0?$", "JZ", null));
     patterns.Enqueue(Tuple.Create<string, string, MatchEvaluator>(@"\.$|\.0+$", ".Z", null));
     patterns.Enqueue(Tuple.Create<string, string, MatchEvaluator>(@"^0+$|^[^.]{0}$", "0.Z", null));

     while (patterns.Count > ) {
         var pattern = patterns.Dequeue();
         if (pattern.Item3 != null) {
             process = Regex.Replace(process, pattern.Item1, pattern.Item3);
         }
         else {
             process = Regex.Replace(process, pattern.Item1, pattern.Item2);
         }
     }

     #endregion

     #region Step3 翻译中间字符串
     StringBuilder result = new StringBuilder();
     var translatorDic = new Dictionary<char, string> {
         {'',"零"},{'',"壹"},{'',"贰"},{'',"叁"},{'',"肆"},{'',"伍"},{'',"陆"},{'',"柒"},{'',"捌"},{'',"玖"},
         {'S',"拾"},{'B',"佰"},{'Q',"仟"},{'W',"萬"},{'Y',"亿"},
         {'￥',"人民币"},{'-',"负"},{'.',"圆"},{'J',"角"},{'F',"分"},{'Z',"整"}
     };
     for (int i = ; i < process.Length; i++) {
         result.Append(translatorDic[process[i]]);
     }
     #endregion

     return result.ToString();
 }

http://www.cnblogs.com/roucheng/

一个人民币大写的扩展方法。感觉还是有点复杂，请朋友们帮忙优化下或是给个思路。