C#转换人民币大小金额

/// <summary>   
        /// 转换人民币大小金额   
        /// </summary>   
        /// <param name="num">金额</param>   
        /// <returns>返回大写形式</returns>   
        public static string GetChineseMoney(decimal num)  
        {  
            string str1 = "零壹贰叁肆伍陆柒捌玖";            //0-9所对应的汉字   
            string str2 = "万仟佰拾亿仟佰拾万仟佰拾元角分"; //数字位所对应的汉字   
            string str3 = "";    //从原num值中取出的值   
            string str4 = "";    //数字的字符串形式   
            string str5 = "";  //人民币大写金额形式   
            int i;    //循环变量   
            int j;    //num的值乘以100的字符串长度   
            string ch2 = "";    //数字的汉语读法   
            string ch3 = "";    //数字位的汉字读法   
            int nzero = 0;  //用来计算连续的零值是几个   
            int temp;            //从原num值中取出的值   
 
            if (DbUtils.Language.ToLower() == "en") return "";  
            num = Math.Round(Math.Abs(num), 2);    //将num取绝对值并四舍五入取2位小数   
            str4 = ((long)(num * 100)).ToString();        //将num乘100并转换成字符串形式   
            j = str4.Length;      //找出最高位   
            if (j > 15) { return "溢出"; }  
            str2 = str2.Substring(15 - j);   //取出对应位数的str2的值。如：200.55,j为5所以str2=佰拾元角分   
 
            //循环取出每一位需要转换的值   
            for (i = 0; i < j; i++)  
            {  
                str3 = str4.Substring(i, 1);          //取出需转换的某一位的值   
                temp = Convert.ToInt32(str3);      //转换为数字   
                if (i != (j - 3) && i != (j - 7) && i != (j - 11) && i != (j - 15))  
                {  
                    //当所取位数不为元、万、亿、万亿上的数字时   
                    if (str3 == "0")  
                    {  
                        ch2 = "";  
                        ch3 = "";  
                        nzero = nzero + 1;  
                    }  
                    else 
                    {  
                        if (str3 != "0" && nzero != 0)  
                        {  
                            ch2 = "零" + str1.Substring(temp * 1, 1);  
                            ch3 = str2.Substring(i, 1);  
                            nzero = 0;  
                        }  
                        else 
                        {  
                            ch2 = str1.Substring(temp * 1, 1);  
                            ch3 = str2.Substring(i, 1);  
                            nzero = 0;  
                        }  
                    }  
                }  
                else 
                {  
                    //该位是万亿，亿，万，元位等关键位   
                    if (str3 != "0" && nzero != 0)  
                    {  
                        ch2 = "零" + str1.Substring(temp * 1, 1);  
                        ch3 = str2.Substring(i, 1);  
                        nzero = 0;  
                    }  
                    else 
                    {  
                        if (str3 != "0" && nzero == 0)  
                        {  
                            ch2 = str1.Substring(temp * 1, 1);  
                            ch3 = str2.Substring(i, 1);  
                            nzero = 0;  
                        }  
                        else 
                        {  
                            if (str3 == "0" && nzero >= 3)  
                            {  
                                ch2 = "";  
                                ch3 = "";  
                                nzero = nzero + 1;  
                            }  
                            else 
                            {  
                                if (j >= 11)  
                                {  
                                    ch2 = "";  
                                    nzero = nzero + 1;  
                                }  
                                else 
                                {  
                                    ch2 = "";  
                                    ch3 = str2.Substring(i, 1);  
                                    nzero = nzero + 1;  
                                }  
                            }  
                        }  
                    }  
                }  
                if (i == (j - 11) || i == (j - 3))  
                {  
                    //如果该位是亿位或元位，则必须写上   
                    ch3 = str2.Substring(i, 1);  
                }  
                str5 = str5 + ch2 + ch3;  
 
                if (i == j - 1 && str3 == "0")  
                {  
                    //最后一位（分）为0时，加上“整”   
                    str5 = str5 + '整';  
                }  
            }  
            if (num == 0)  
            {  
                str5 = "零元整";  
            }  
            return str5;  
        }