C#数字转英文(货币)大写

private void Page_Load(object sender, System.EventArgs e)
        {
            //调用
            Response.Write(new Number2English().NumberToString(123456789.12));
        }

Number2English#region Number2English
        public class Number2English
        {
            private string[] StrNO = new string[19]; 
            private string[] Unit = new string[8]; 
            private string[] StrTens = new string[9];

            NumberToString#region NumberToString
            public string NumberToString(double Number) 
            { 
                string Str; 
                string BeforePoint; 
                string AfterPoint; 
                string tmpStr; 
                int nBit; 
                string CurString;
                int nNumLen;
                Init(); 
                Str = Convert.ToString(Math.Round(Number,2)); 
                if (Str.IndexOf(".")==-1) 
                { 
                    BeforePoint = Str; 
                    AfterPoint = ""; 
                } 
                else 
                { 
                    BeforePoint = Str.Substring(0,Str.IndexOf(".")); 
                    AfterPoint = Str.Substring(Str.IndexOf(".")+1,Str.Length - Str.IndexOf(".")-1); 
                }
                if (BeforePoint.Length > 12) 
                { 
                    return null; 
                }
                Str = "";
                while (BeforePoint.Length > 0) 
                {
                    nNumLen = Len(BeforePoint); 
                    if (nNumLen % 3 == 0) 
                    { 
                        CurString = Left(BeforePoint, 3); 
                        BeforePoint = Right(BeforePoint, nNumLen - 3); 
                    } 
                    else 
                    { 
                        CurString = Left(BeforePoint, (nNumLen % 3)); 
                        BeforePoint = Right(BeforePoint, nNumLen - (nNumLen % 3)); 
                    }
                    nBit = Len(BeforePoint) / 3; 
                    tmpStr = DecodeHundred(CurString);
                    if((BeforePoint == Len(BeforePoint).ToString() || nBit ==0) && Len(CurString) ==3)
                    {
                        if (System.Convert.ToInt32(Left(CurString, 1)) != 0 & System.Convert.ToInt32(Right(CurString, 2)) != 0) 
                        { 
                            tmpStr = Left(tmpStr, tmpStr.IndexOf(Unit[3]) + Len(Unit[3])) + Unit[7] + " " + Right(tmpStr, Len(tmpStr) - (tmpStr.IndexOf(Unit[3]) + Len(Unit[3]))); 
                        } 
                        else 
                        { 
                            tmpStr = Unit[7] + " " + tmpStr; 
                        }
                    }
                    if (nBit == 0) 
                    { 
                        Str = Convert.ToString(Str + " " + tmpStr).Trim();
                    } 
                    else 
                    { 
                        Str = Convert.ToString(Str + " " + tmpStr + " " + Unit[nBit-1]).Trim(); 
                    }
                    if (Left(Str, 3) == Unit[7]) 
                    { 
                        Str = Convert.ToString(Right(Str, Len(Str) - 3)).Trim(); 
                    }
                    if( BeforePoint == Len(BeforePoint).ToString())
                    {
                        return "";
                    }
                }
                BeforePoint = Str; 
                if (Len(AfterPoint) > 0) 
                { 
                    AfterPoint = Unit[5] + " " + DecodeHundred(AfterPoint) + " " + Unit[6]; 
                } 
                else 
                { 
                    AfterPoint = Unit[4]; 
                } 
                return BeforePoint + " " + AfterPoint;

            }

            #endregion

            Init#region Init
            private void Init() 
            { 
                if (StrNO[0] != "One") 
                { 
                    StrNO[0] = "One"; 
                    StrNO[1] = "Two"; 
                    StrNO[2] = "Three"; 
                    StrNO[3] = "Four"; 
                    StrNO[4] = "Five"; 
                    StrNO[5] = "Six"; 
                    StrNO[6] = "Seven"; 
                    StrNO[7] = "Eight"; 
                    StrNO[8] = "Nine"; 
                    StrNO[9] = "Ten"; 
                    StrNO[10] = "Eleven"; 
                    StrNO[11] = "Twelve"; 
                    StrNO[12] = "Thirteen"; 
                    StrNO[13] = "Fourteen"; 
                    StrNO[14] = "Fifteen"; 
                    StrNO[15] = "Sixteen"; 
                    StrNO[16] = "Seventeen"; 
                    StrNO[17] = "Eighteen"; 
                    StrNO[18] = "Nineteen"; 
                    StrTens[0] = "Ten"; 
                    StrTens[1] = "Twenty"; 
                    StrTens[2] = "Thirty"; 
                    StrTens[3] = "Forty"; 
                    StrTens[4] = "Fifty"; 
                    StrTens[5] = "Sixty"; 
                    StrTens[6] = "Seventy"; 
                    StrTens[7] = "Eighty"; 
                    StrTens[8] = "Ninety"; 
                    Unit[0] = "Thousand"; 
                    Unit[1] = "Million"; 
                    Unit[2] = "Billion"; 
                    Unit[3] = "Hundred"; 
                    Unit[4] = "Only"; 
                    Unit[5] = "Point"; 
                    Unit[6] = "Cent"; 
                    Unit[7] = "And"; 
                } 
            }

            #endregion

            DecodeHundred#region DecodeHundred
            private string DecodeHundred(string HundredString) 
            { 
                int tmp;
                string rtn="";
                if( Len(HundredString) > 0 && Len(HundredString) <= 3)
                {
                    switch (Len(HundredString))
                    {
                        case 1:
                            tmp = System.Convert.ToInt32(HundredString); 
                            if (tmp != 0) 
                            { 
                                rtn=StrNO[tmp-1].ToString(); 
                            } 
                            break;
                        case 2:
                            tmp = System.Convert.ToInt32(HundredString); 
                            if (tmp != 0) 
                            { 
                                if ((tmp < 20)) 
                                { 
                                    rtn=StrNO[tmp-1].ToString(); 
                                } 
                                else 
                                { 
                                    if (System.Convert.ToInt32(Right(HundredString, 1)) == 0) 
                                    { 
                                        rtn=StrTens[Convert.ToInt32(tmp / 10)-1].ToString(); 
                                    } 
                                    else 
                                    { 
                                        rtn=Convert.ToString(StrTens[Convert.ToInt32(tmp / 10)-1] + "-" + StrNO[System.Convert.ToInt32(Right(HundredString, 1))-1]);
                                    } 
                                } 
                            } 
                            break;
                        case 3:
                            if (System.Convert.ToInt32(Left(HundredString, 1)) != 0) 
                            { 
                                rtn=Convert.ToString(StrNO[System.Convert.ToInt32(Left(HundredString, 1))-1] + " " + Unit[3] + " " + DecodeHundred(Right(HundredString, 2))); 
                            } 
                            else 
                            { 
                                rtn=DecodeHundred(Right(HundredString, 2)).ToString(); 
                            } 
                            break;
                        default:
                            break;
                    }
                }
                return rtn;
            }

            #endregion

            Left#region Left
            private string Left(string str,int n)
            {
                return str.Substring(0,n);
            }
            #endregion

            Right#region Right
            private string Right(string str,int n)
            {
                return str.Substring(str.Length-n,n);
            }
            #endregion

            Len#region Len
            private int Len(string str)
            {
                return str.Length;
            }
            #endregion
        }
        #endregion