C# 人民幣大寫金額轉換

/// <summary> 
     /// 轉換人民幣大小金額 
     /// </summary> 
     /// <param name="num">金額</param> 
     /// <returns>返回大寫形式</returns> 
     public static string CmycurD(decimal num)
     {
         string str1 = "零壹貳叄肆伍陸柒捌玖";            //0-9所對應的漢字 
         string str2 = "萬仟佰拾億仟佰拾萬仟佰拾元角分"; //數字位所對應的漢字 
         string str3 = "";    //從原num值中取出的值 
         string str4 = "";    //數字的字符串形式 
         string str5 = "";  //人民幣大寫金額形式 
         int i;    //循環變量 
         int j;    //num的值乘以100的字符串長度 
         string ch1 = "";    //數字的漢語讀法 
         string ch2 = "";    //數字位的漢字讀法 
         int nzero = 0;  //用來計算連續的零值是幾個 
         int temp;            //從原num值中取出的值 
 
         num = Math.Round(Math.Abs(num), 2);    //將num取絕對值並四捨五入取2位小數 
         str4 = ((long)(num * 100)).ToString();        //將num乘100並轉換成字符串形式 
         j = str4.Length;      //找出最高位 
         if (j > 15) { return "溢出"; }
         str2 = str2.Substring(15 - j);   //取出對應位數的str2的值。如：200.55,j爲5因此str2=佰拾元角分 
 
         //循環取出每一位須要轉換的值 
         for (i = 0; i < j; i++)
         {
             str3 = str4.Substring(i, 1);          //取出需轉換的某一位的值 
             temp = Convert.ToInt32(str3);      //轉換爲數字 
             if (i != (j - 3) && i != (j - 7) && i != (j - 11) && i != (j - 15))
             {
                 //當所取位數不爲元、萬、億、萬億上的數字時 
                 if (str3 == "0")
                 {
                     ch1 = "";
                     ch2 = "";
                     nzero = nzero + 1;
                 }
                 else
                 {
                     if (str3 != "0" && nzero != 0)
                     {
                         ch1 = "零" + str1.Substring(temp * 1, 1);
                         ch2 = str2.Substring(i, 1);
                         nzero = 0;
                     }
                     else
                     {
                         ch1 = str1.Substring(temp * 1, 1);
                         ch2 = str2.Substring(i, 1);
                         nzero = 0;
                     }
                 }
             }
             else
             {
                 //該位是萬億，億，萬，元位等關鍵位 
                 if (str3 != "0" && nzero != 0)
                 {
                     ch1 = "零" + str1.Substring(temp * 1, 1);
                     ch2 = str2.Substring(i, 1);
                     nzero = 0;
                 }
                 else
                 {
                     if (str3 != "0" && nzero == 0)
                     {
                         ch1 = str1.Substring(temp * 1, 1);
                         ch2 = str2.Substring(i, 1);
                         nzero = 0;
                     }
                     else
                     {
                         if (str3 == "0" && nzero >= 3)
                         {
                             ch1 = "";
                             ch2 = "";
                             nzero = nzero + 1;
                         }
                         else
                         {
                             if (j >= 11)
                             {
                                 ch1 = "";
                                 nzero = nzero + 1;
                             }
                             else
                             {
                                 ch1 = "";
                                 ch2 = str2.Substring(i, 1);
                                 nzero = nzero + 1;
                             }
                         }
                     }
                 }
             }
             if (i == (j - 11) || i == (j - 3))
             {
                 //若是該位是億位或元位，則必須寫上 
                 ch2 = str2.Substring(i, 1);
             }
             str5 = str5 + ch1 + ch2;
 
             if (i == j - 1 && str3 == "0")
             {
                 //最後一位（分）爲0時，加上「整」 
                 str5 = str5 + '整';
             }
         }
         if (num == 0)
         {
             str5 = "零元整";
         }
         return str5;
     }