人民币大写转化函数（VB.NET版）
原版C#版的，可以看原作者的代码。
Public Class Currency
Inherits Object
Private Const CST_CAPSTR_TAIL As String = "整"
Private Const CST_CAPSSTR_ZERO As String = "零"
Private Const CST_CAPSSTR As String = CST_CAPSSTR_ZERO & "壹贰叁肆伍陆柒捌玖"
Private Const CST_POSSTR_YUAN As String = "元"
Private Const CST_POSSTR As String = "万仟佰拾亿仟佰拾万仟佰拾" & CST_POSSTR_YUAN & "角分"
Private Const CST_CHNNUM_ZERO As String = CST_CAPSSTR_ZERO & CST_POSSTR_YUAN & CST_CAPSTR_TAIL
Private Shared ReadOnly CST_MAXLENGTH As Integer = CST_POSSTR.Length
Public Shared Function ConvertToCapsString(ByVal dec As Decimal) As String
Dim i, j, nZero As Integer
Dim strDec, strPos, ch1, ch2 As String
Dim chnNum, chnPos As String
Dim strOnePosValue As String
Dim intOnePosValue As Integer
'将num取绝对值并四舍五入取2位小数
dec = Math.Round(Math.Abs(dec), 2)
'将num乘100并转换成字符串形式
strDec = Convert.ToInt64(dec * 100).ToString
'找出最高位
j = strDec.Length
If i > CST_MAXLENGTH Then
Throw New OverflowException
ElseIf dec = 0 Then
'零元的时候，直接输出“零元整”
chnNum = CST_CHNNUM_ZERO
Else
'取出对应位数的str2的值。如：200.55,j为5所以str2=佰拾元角分
strPos = CST_POSSTR.Substring(CST_MAXLENGTH - j)
'循环取出每一位需要转换的值
For i = 0 To j - 1
'取出需转换的某一位的值
strOnePosValue = strDec.Substring(i, 1)
'转换为数字
intOnePosValue = Convert.ToInt32(strOnePosValue)
If i <> j - 3 AndAlso i <> j - 7 AndAlso i <> j - 15 Then
'当所取位数不为元、万、亿、万亿上的数字时
If strOnePosValue = "0" Then
'此位为零，只计入零的个数。不转换。
ch1 = ""
ch2 = ""
nZero = nZero + 1
Else
'此位非零
If nZero = 0 Then
'前面没有零，追加此位的中文
ch1 = CST_CAPSSTR.Substring(intOnePosValue * 1, 1)
ch2 = strPos.Substring(i, 1)
nZero = 0
Else
'前面已经有零，无论有多少只加一个零，然后追加此位的中文
ch1 = CST_CAPSSTR_ZERO & CST_CAPSSTR.Substring(intOnePosValue * 1, 1)
ch2 = strPos.Substring(i, 1)
nZero = 0
End If
End If
Else
'该位是万亿，亿，万，元位等关键位
If strOnePosValue <> "0" AndAlso nZero <> 0 Then
ch1 = CST_CAPSSTR_ZERO & CST_CAPSSTR.Substring(intOnePosValue * 1, 1)
ch2 = strPos.Substring(i, 1)
nZero = 0
Else
If strOnePosValue <> "0" AndAlso nZero = 0 Then
ch1 = CST_CAPSSTR.Substring(intOnePosValue * 1, 1)
ch2 = strPos.Substring(i, 1)
nZero = 0
Else
If strOnePosValue = "0" AndAlso nZero >= 3 Then
ch1 = ""
ch2 = ""
nZero = nZero + 1
Else
If j > 11 Then
'亿以上
ch1 = ""
nZero = nZero + 1
Else
'亿以下
ch1 = ""
ch2 = strPos.Substring(i, 1)
nZero = nZero + 1
End If
End If
End If
End If
End If
If i = j - 11 OrElse i = j - 3 Then
'如果该位是亿位或元位，则必须写上
ch2 = strPos.Substring(i, 1)
End If
chnNum = chnNum & ch1 & ch2
If i = j - 1 AndAlso strOnePosValue = "0" Then
'最后一位（分）为0时，加上“整”
chnNum = chnNum & CST_CAPSTR_TAIL
End If
Next
End If
Return chnNum
End Function
Public Shared Function ConvertToCapsString(ByVal dec As String) As String
Dim num As Decimal = 0
Try
num = Convert.ToDecimal(dec)
Catch ex As Exception
Throw New InvalidateDecimalFormatException(dec)
End Try
Return ConvertToCapsString(num)
End Function
Public Class OverflowException
Inherits Exception
Public Sub New()
MyBase.New("Overflow in parameter. To string length must less than " & CST_MAXLENGTH & ".")
End Sub
End Class
Public Class InvalidateDecimalFormatException
Inherits Exception
Private m_val As String
Public ReadOnly Property Value() As String
Get
Return m_val
End Get
End Property
Public Sub New(ByVal val As String)
MyBase.New("The string value cannot be converted to decimal.")
m_val = val
End Sub
End Class
End Class
