C#笔记：数字转大写金额

private void textBox1_TextChanged(object sender, EventArgs e)
        {
            this.textBox1.TextChanged -= new EventHandler(textBox1_TextChanged);
            this.textBox1.Text = GetChineseMoney.GetEngFormatNum(this.textBox1.Text);
            this.textBox1.Select(this.textBox1.TextLength, 0); 
            this.textBox2.Text = GetChineseMoney.ConvertToChineseMoney (this.textBox1.Text);
            this.textBox1.TextChanged += new EventHandler(textBox1_TextChanged);
        }

public class GetChineseMoney
    {
        private static string ConvertSingleUpperNum(char inputChar)
        {
            switch (inputChar)
            {
                case '1':
                    return "壹";
                case '2':
                    return "贰";
                case '3':
                    return "叁";
                case '4':
                    return "肆";
                case '5':
                    return "伍";
                case '6':
                    return "陆";
                case '7':
                    return "柒";
                case '8':
                    return "捌";
                case '9':
                    return "玖";
                case '0':
                    return "零";
            }
            return "";
        }
        /// <summary>
        /// 把4位数字转换成相应的形式
        /// </summary>
        /// <param name="inputStr">传入的字符</param>
        /// <returns>处理好的大写字符</returns>
        private static string Convert4Num(string inputStr)
        {
            //while(inputStr.Length<4)
            //{
            //    inputStr = "0" + inputStr;
            //}
            string result = "";
            result += ConvertSingleUpperNum(inputStr[0]) + "千";
            result += ConvertSingleUpperNum(inputStr[1]) + "百";
            result += ConvertSingleUpperNum(inputStr[2]) + "十";
            result += ConvertSingleUpperNum(inputStr[3]);
            result = result.Replace("零千", "零");
            result = result.Replace("零百", "零");
            result = result.Replace("零十", "零");
            return result;
        }
        //每四位获取单位
        private static string[] GetUnit(int length)
        {
            string[] result = new string[length];
            result[length - 1] = "";
            for (int i = length - 2; i >= 0; i--)
            {
                if ((i - length) * (-1) % 2 == 0)
                {
                    result[i] = "万";
                }
                else
                {
                    result[i] = "亿";
                }
            }
            return result;
        }
        //主方法
        public static string ConvertToChineseMoney(string inputStr)
        {
            string[] strArray = null;
            if (inputStr.IndexOf('.') >= 0)
            {
                strArray = inputStr.Split('.');
                if (strArray == null || strArray.Length != 2)
                {
                    return "错误";
                }
                string strAbovePoint = ConvertInt(strArray[0]);
                string strAfterPoint = "";
                if (strArray[1].Length == 1)
                {
                    strAfterPoint += ConvertSingleUpperNum(strArray[1][0]) + "角";
                }
                if (strArray[1].Length >= 2)
                {
                    strAfterPoint += ConvertSingleUpperNum(strArray[1][0]) + "角" + ConvertSingleUpperNum(strArray[1][1]) + "分";
                }
                return strAbovePoint + "元" + strAfterPoint;
            }
            else
            {
                return ConvertInt(inputStr);
            }
        }
        private static string ConvertInt(string inputStr)
        {
            if (inputStr.Length >= 22)
            {
                return "溢出";
            }
            if (string.IsNullOrEmpty(inputStr))
            {
                return "";
            }
            string result = "";
            inputStr = inputStr.Replace(",", "");
            while (inputStr.Length % 4 != 0)
            {
                inputStr = "0" + inputStr;
            }
            int colLength = inputStr.Length / 4;
            string[] strCol = new string[colLength];
            for (int i = 0, j = 0; i < inputStr.Length; i = i + 4, j++)
            {
                strCol[j] = inputStr.Substring(i, 4);
            }
            string[] danwei = GetUnit(colLength);
            for (int i = 0; i < colLength; i++)
            {
                if (strCol[i] == "0000" && danwei[i] == "万")
                {
                    result += Convert4Num(strCol[i]);
                }
                else
                {
                    result += Convert4Num(strCol[i]) + danwei[i];
                }
            }
            while (result.IndexOf("零零") >= 0)
            {
                result = result.Replace("零零", "零");
            }
            result = result.Replace("零万", "万");
            result = result.Replace("零亿", "亿");
            while (result.StartsWith("零"))
            {
                result = result.Substring(1);
            }
            while (result.EndsWith("零"))
            {
                result = result.Substring(0, result.Length - 1);
            }
            return result;
        }
        
        public static string GetEngFormatNum(string inputStr)
        {            
            string tempStr = inputStr.Replace(",", "");            
            string tail = "";
            if (tempStr.IndexOf('.') >= 0)
            {
                tail = tempStr.Substring(tempStr.IndexOf('.'));                
                tempStr = tempStr.Substring(0, tempStr.IndexOf('.'));
            }
            string result = "";
            for (int i = tempStr.Length - 1; i >= 0; i--)
            {
                if ((tempStr.Length - i) % 3 == 0)
                {
                    result = "," + tempStr[i] + result;
                }
                else
                {
                    result = tempStr[i] + result;
                }
            }
            if (result.StartsWith(","))
            {
                result = result.Substring(1);
            }
            return result + tail;
        }
    }