NumberToChineseConverter.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Data;

namespace System.Windows.Controls
{
    [ValueConversion(typeof(string), typeof(string))]
    public class NumberToChineseConverter : IValueConverter
    {

        public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            string valueString = value.ToString();

            decimal num = 0;

            if (!decimal.TryParse(valueString, out num))
            {
                return DependencyProperty.UnsetValue;
            }

            string[] tmp_Array = num.ToString().Split(new char[] { '.' }, StringSplitOptions.None);

            // 这个是小数点前的数字
            string beforeDecimalPoint = tmp_Array[0];
            // 这个是小数点后的数字
            string afterDecimalPoint = tmp_Array.Length > 1 ? tmp_Array[1] : string.Empty;

            // 先将数字四位为一组分别放到一个List中
            List<ChineseNum> beforeDecimalPointGroup = new List<ChineseNum>();
            int maxIndex = beforeDecimalPoint.Length - 1;
            int count = 0;
            string tmpValue = string.Empty;

            for (var n = maxIndex; n >= 0; n--)
            {
                tmpValue = string.Format("{0}{1}", beforeDecimalPoint[n].ToString(), tmpValue);

                if (count == 3 || n == 0)
                {
                    var number = new ChineseNum()
                    {
                        UnitIndex = beforeDecimalPointGroup.Count,
                        Number = tmpValue
                    };

                    beforeDecimalPointGroup.Add(number);

                    count = 0;
                    tmpValue = string.Empty;
                }
                else
                {
                    count++;
                }
            }

            string result = string.Empty;
            var tmp = beforeDecimalPointGroup.OrderBy(c => c.UnitIndex);

            // 将每4位的数字组合起来
            foreach (var a in tmp)
            {
                result = string.Format("{1}{0}", result, a.Value);
            }

            // 整合小数部分
            if (!string.IsNullOrEmpty(afterDecimalPoint))
            {
                // 增加点
                result = string.Format("{0}{1}", result, "点");

                // 整合每个位置上得小数
                for (var n = 0; n < afterDecimalPoint.Length; n++)
                {
                    result = string.Format("{0}{1}", result, GetNumber(int.Parse(afterDecimalPoint[n].ToString())));
                }
            }

            return result;
        }

        static string GetNumber(int n)
        {
            string num = string.Empty;

            switch (n)
            {
                case 0: num = "零"; break;
                case 1: num = "壹"; break;
                case 2: num = "贰"; break;
                case 3: num = "叁"; break;
                case 4: num = "肆"; break;
                case 5: num = "伍"; break;
                case 6: num = "陆"; break;
                case 7: num = "柒"; break;
                case 8: num = "捌"; break;
                case 9: num = "玖"; break;
                default: break;
            }

            return num;
        }

        public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    }

    public class ChineseNum
    {
        public int UnitIndex { get; set; }

        public string Number { get; set; }

        public string Value
        {
            get
            {
                // 当只有一个0时，返回0，此例仅适用于数字0
                if (Number == "0")
                {
                    return PlaceHolder;
                }

                // 当只具备0时，该四位数字不需要显示
                if (string.IsNullOrEmpty(Number.Trim(new char[] { '0' })))
                {
                    return string.Empty;
                }
                else // 当具备其他数字时，组合中文大写数字
                {
                    string value = string.Empty;

                    for (var n = 0; n < Number.Length; n++)
                    {
                        value = string.Format("{0}{1}{2}", value, GetNumber(n), GetUnit(n));
                    }

                    // 组合当前4位数所在的单位
                    return string.Format("{0}{1}", value, UnitValue(UnitIndex));
                }
            }
        }

        public string PlaceHolder
        {
            get
            {
                return "零";
            }
        }

        string GetNumber(int index)
        {
            var n = int.Parse(Number[index].ToString());
            string num = string.Empty;

            // 当0为最后一位时 或者当下一位也为0时 不显示该位
            if (n == 0 && ((Number.Length == index + 1) || Number[index + 1] == '0'))
            {
                return num;
            }

            switch (n)
            {
                case 0: num = "零"; break;
                case 1: num = "壹"; break;
                case 2: num = "贰"; break;
                case 3: num = "叁"; break;
                case 4: num = "肆"; break;
                case 5: num = "伍"; break;
                case 6: num = "陆"; break;
                case 7: num = "柒"; break;
                case 8: num = "捌"; break;
                case 9: num = "玖"; break;
                default: break;
            }

            return num;
        }

        /// <summary>
        /// 获取当前位置上得数字的中文大写单位
        /// </summary>
        /// <param name="index"></param>
        /// <returns></returns>
        string GetUnit(int index)
        {
            string unit = string.Empty;

            int unitIndex = Number.Length - index;

            if (Number[index] == '0')
                return unit;

            switch (unitIndex)
            {
                case 4: unit = "千"; break;
                case 3: unit = "百"; break;
                case 2: unit = "拾"; break;
            }

            return unit;
        }

        string UnitValue(int index)
        {
            string unit = string.Empty;

            switch (index)
            {
                case 1: unit = "万"; break;
                case 2: unit = "亿"; break;
                case 3: unit = "兆"; break;
                case 4: unit = "京"; break;
                case 5: unit = "垓"; break;
                case 6: unit = "秭"; break;
                default: break;
            }

            return unit;
        }
    }
}

Number: 12345

Chinese: 壹万贰千叁百肆拾伍