在显示类型预期错误的vb.net中将数字金额转换为单词

Private Function ConvertNumberToWords(ByVal number As Integer) As String
    Dim unitsMap As String() = {"Zero", "One", "Two", "Three", "Four", "Five", "Six", "Seven", "Eight", "Nine", "Ten", "Eleven", "Twelve", "Thirteen", "Fourteen", "Fifteen", "Sixteen", "Seventeen", "Eighteen", "Nineteen"}
    Dim tensMap As String() = {"", "", "Twenty", "Thirty", "Forty", "Fifty", "Sixty", "Seventy", "Eighty", "Ninety"}

    If number < 20 Then
        Return unitsMap(number)
    End If

    If number < 100 Then
        Return tensMap(number \ 10) + " " + unitsMap(number Mod 10)
    End If

    If number < 1000 Then
        Return unitsMap(number \ 100) + " Hundred " + ConvertNumberToWords(number Mod 100)
    End If

    If number < 1000000 Then
        Return ConvertNumberToWords(number \ 1000) + " Thousand " + ConvertNumberToWords(number Mod 1000)
    End If

    If number < 1000000000 Then
        Return ConvertNumberToWords(number \ 1000000) + " Million " + ConvertNumberToWords(number Mod 1000000)
    End If

    Return ""
End Function

Dim amount As Integer = 12345
Dim words As String = ConvertNumberToWords(amount)
Console.WriteLine(words)

Dim amount As Integer = 12345
Dim words As String = ConvertNumberToWords(amount)
Dim result As String = "Amount in words: " + words
Console.WriteLine(result)