金额大小写转换

来源：C#编程宝典 例16.01

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace ConvertMoney
{
    public partial class Form1 : Form
    {
        private const string STR_UPPER = "零壹贰叁肆伍陆柒捌玖";

        private const string STR_UNIT = "分角元拾佰仟萬拾佰仟亿";

 

        public Form1()
        {
            InitializeComponent();
        }

       /// <summary>

        /// 转换整数为大写金额

        /// </summary>

        /// <param name="capValue">整数值</param>

        /// <returns>返回大写金额</returns>

        private string ConvertIntToUpper(string strValue)
        {
            string strCurrCap = "";
            string strCapResult = "";
            int intPrevChar = -1;
            int intCurrChar = 0;
            int intPosIndex = 2;
            if (Convert.ToDouble(strValue) == 0) return "";
            for (int i = strValue.Length - 1; i >= 0; i--)
            {
                intCurrChar = Convert.ToInt32(strValue.Substring(i, 1));
                if (intCurrChar != 0)
                {
                    strCurrCap = STR_UPPER.Substring(intCurrChar, 1) + STR_UNIT.Substring(intPosIndex, 1);
                }
                else
                {
                    switch (intPosIndex)
                    {
                        case 2: strCurrCap = "元"; break;
                        case 6: strCurrCap = "萬"; break;
                        case 10: strCurrCap = "亿"; break;
                        default: break;
                    }
                    if (intPrevChar != 0)
                    {
                        if (strCurrCap != "")
                        {
                            if (strCurrCap != "元")
                                strCurrCap += "零";
                        }
                        else
                        {
                            strCurrCap = "零";
                        }
                    }
                }
                strCapResult = strCurrCap + strCapResult;
                intPrevChar = intCurrChar;
                intPosIndex += 1;
                strCurrCap = "";
            }
            return strCapResult;
        }

 

        /// <summary>

        /// 转换小数为大写金额

        /// </summary>

        /// <param name="capValue">小数值</param>

        /// <param name="isExistInt">是否存在整数位</param>

        /// <returns>返回大写金额</returns>

        private string ConvertDecToUpper(string strCapValue, bool isExistInt)
        {
            string strCurrCap = "";
            string strCapResult = "";
            int intCurrChar = 0;
            int intPosIndex = 1;
            if (Convert.ToDouble(strCapValue) == 0) return "";
            for (int i = 0; i < strCapValue.Length; i++)
            {
                intCurrChar = Convert.ToInt32(strCapValue.Substring(i, 1));
                if (intCurrChar == 0)//若当前的数值为零
                {
                    if (i == 0)//若是"角"单位的索引
                    {
                        if (isExistInt)//若存在整数部分
                        {
                            strCurrCap = "零";
                        }
                    }
                }
                else//若当前的数值不为零
                {
                    strCurrCap = STR_UPPER.Substring(intCurrChar, 1) + STR_UNIT.Substring(intPosIndex, 1);
                }
                strCapResult += strCurrCap;
                intPosIndex -= 1;
                strCurrCap = "";
            }
            return strCapResult;
        }

        private void btnConfirm_Click(object sender, EventArgs e)
        {
            if (!String.IsNullOrEmpty(txtALower.Text.Trim()))
            {
                string strCapResult = "";
                string strCapValue = String.Format("{0:F2}", Convert.ToDouble(txtALower.Text));
                int intDotPos = strCapValue.IndexOf(".");//点的位置
                int intBeginPos = 0;
                string strCapInt = strCapValue.Substring(intBeginPos, intDotPos);//取出整数部分
                string strCapDec = strCapValue.Substring(intDotPos + 1);//取出小数部分
                strCapResult = ConvertIntToUpper(strCapInt) + ConvertDecToUpper(strCapDec, Convert.ToInt32(strCapDec) >= 1 ? true : false);
                if (Convert.ToDouble(strCapDec) == 0) strCapResult += "整";
                this.txtAUpper.Text = strCapResult;
            }
        }

        private void txtALower_KeyPress(object sender, KeyPressEventArgs e)
        {

            if (String.IsNullOrEmpty(txtALower.Text) && e.KeyChar.ToString() == ".")
            {
                e.Handled = true;
            }
            if (txtALower.Text.Contains(".") && e.KeyChar.ToString() == ".")
            {
                e.Handled = true;
            }
            if (!Char.IsDigit(e.KeyChar) && e.KeyChar.ToString() != "." && e.KeyChar.ToString() != "")
            {
                e.Handled = true;
            }
        }
    }
}