问将VB6/VBA复制到VB.net算术操作会导致溢出。

EN

Private oTest                   As Class1
Private InitDone                As Boolean
Private Map1(0 To 63)           As Byte
Private Map2(0 To 127)          As Byte

#If VBA7 Then
  Public Declare PtrSafe Function GetSystemMetrics Lib "user32" (ByVal nIndex As Long) As Long
#Else
  Public Declare Function GetSystemMetrics Lib "user32" (ByVal nIndex As Long) As Long
#End If

Private Declare Sub CopyMemoryByref Lib "Kernel32.dll" & _
                    Alias "RtlMoveMemory" (ByRef dest As Integer, ByRef & _
                    source As Integer, ByVal numBytes As Integer)

Private Declare Function VarPtr Lib "vb40032.dll" & _
                         Alias "VarPtr" (lpObject As Integer) As Long

Public Function EncryptData(ByRef bytMessage() As Byte, ByRef bytPassword() As Byte) As Byte()
        Dim bytKey(31) As Byte
        Dim bytIn() As Byte
        Dim bytOut() As Byte
        Dim bytTemp(31) As Byte
        Dim lCount, lLength As Integer
        Dim lEncodedLength, lPosition As Integer
        Dim bytLen(3) As Byte

        If Not IsInitialized(bytMessage) Then Exit Function
        If Not IsInitialized(bytPassword) Then Exit Function

        For lCount = 0 To UBound(bytPassword)
            bytKey(lCount) = bytPassword(lCount) : If lCount = 31 Then Exit For
        Next lCount

        gentables()
        gkey(8, 8, bytKey)
        lLength = UBound(bytMessage) + 1 : lEncodedLength = lLength + 4

        If lEncodedLength Mod 32 <> 0 Then lEncodedLength = lEncodedLength + 32 - (lEncodedLength Mod 32)

        ReDim bytIn(lEncodedLength - 1) : ReDim bytOut(lEncodedLength - 1)

        Try
            CopyMemory(VarPtr(bytIn(0)), VarPtr(lLength), 4)
        Catch ex As Exception
            MessageBox.Show(ex.Message)
        End Try

        For lCount = 0 To lEncodedLength - 1 Step 32
           CopyMemory(VarPtr(bytTemp(0)), VarPtr(bytIn(lCount)), 32)
           Encrypt(bytTemp)
           CopyMemory(VarPtr(bytOut(lCount)), VarPtr(bytTemp(0)), 32)
        Next lCount
End Function

Private Sub Command1_Click(ByVal eventSender As System.Object, ByVal eventArgs As System.EventArgs) Handles Command1.Click
    Dim sTemp, sPassword As String

    sTemp = "this is a test"
    Debug.Print("       To encrypt: " & sTemp)

    sPassword = "blk@vjdii:5@fAB5"
    Debug.Print(StrReverse(sPassword))

    sPassword = Str2Hex(strEncrypt(sPassword, StrReverse(sPassword)))
    Debug.Print("       Secret key: " & sPassword)

    sTemp = Str2Hex(strEncrypt(sTemp, sPassword))
    Debug.Print("          Encrypt: " & sTemp)

    sTemp = Base64EncodeString(sTemp)
    Debug.Print("Encrypt w/ Base64: " & sTemp)

    sTemp = Base64DecodeString(sTemp)
    Debug.Print("Decrypt w/ Base64: " & sTemp)

    sTemp = Hex2Str(sTemp)
    Debug.Print("          Decrypt: " & strDecrypt(sTemp, sPassword))
End Sub

 This code works just fine when using it within the VBA excel code. This is the VB6 output: