在退出时将vb6迁移到vb.net

我想将代码从vb6迁移到vb.net.该项目非常基础(不使用dll或组件参考)只是模块

在压缩功能方面,它已经成功.我很开心.但是当解压缩子没有成功.程序挂了.我试过修复它,我发现问题是这样做..退出do..loop语句.

注意:代码在vb6中成功运行.

这是我的解压缩代码

Public Sub Decompress(ByteArray() As Byte)
Dim InpPos As Long
Dim InBitPos As Integer
Dim LowValue As Long
Dim HighValue As Long
Dim RangValue As Long
Dim MidValue As Long
Dim Value As Long
Dim mChar As Byte
Dim i As Integer
Dim Index As Integer
Dim EOF_State As Boolean
Dim TopBit As Long
Dim One(256) As Long
Dim Zero(256) As Long
Call Initiate
LowValue = 0
HighValue = (2 ^ MaxBits) - 1
TopBit = 2 ^ (MaxBits - 1)
InpPos = 0
Value = ReadBitsFromArray(ByteArray, InpPos, InBitPos, MaxBits)
Index = -1
For i = 0 To 256
    One(i) = 1
    Zero(i) = 1
Next
Do
    mChar = 0
    For i = 0 To 7
        Index = (1 * (2 ^ i)) - 1 + mChar
        RangValue = HighValue - LowValue
        MidValue = LowValue + (RangValue * (Zero(Index) / (One(Index) + Zero(Index))))
        If MidValue = LowValue Then MidValue = MidValue + 1
        If MidValue = HighValue - 1 Then MidValue = MidValue - 1
        If Value >= MidValue Then
            mChar = (2 * mChar) + 1
            LowValue = MidValue
            One(Index) = One(Index) + 1
        Else
            mChar = 2 * mChar
            HighValue = MidValue
            Zero(Index) = Zero(Index) + 1
        End If

        Do While (HighValue And TopBit) = (LowValue And TopBit) Or LowValue > HighValue - 255
            If InpPos <= UBound(ByteArray) Then
                Value = (Value And (TopBit - 1)) * 2 + ReadBitsFromArray(ByteArray, InpPos, InBitPos, 1)
                HighValue = (HighValue And (TopBit - 1)) * 2 + 1
                LowValue = (LowValue And (TopBit - 1)) * 2
                If LowValue >= HighValue Then HighValue = (2 ^ MaxBits) - 1
            Else
                EOF_State = True
                Exit Do
            End If
        Loop
        If EOF_State = True Then Exit Do
    Next
    Call AddmCharToArray(OutStream, OutPos, mChar)
Loop
ReDim Preserve OutStream(OutPos - 1)
End Sub

Private Sub Initiate()
ReDim OutStream(500)
OutPos = 0
OutBitCount = 0
OutByteBuf = 0
End Sub

Private Sub AddBitsToOutStream(Number As Integer)
OutByteBuf = OutByteBuf * 2 + Number
OutBitCount = OutBitCount + 1
If OutBitCount = 8 Then
    OutStream(OutPos) = OutByteBuf
    OutBitCount = 0
    OutByteBuf = 0
    OutPos = OutPos + 1
    If OutPos > UBound(OutStream) Then
        ReDim Preserve OutStream(OutPos + 500)
    End If
End If
End Sub

Private Function ReadBitsFromArray(FromArray() As Byte, FromPos As Long, FromBit As Integer, NumBits As Integer) As Long
Dim i As Integer
Dim Temp As Long
For i = 1 To NumBits
    Temp = Temp * 2 + (-1 * ((FromArray(FromPos) And 2 ^ (7 - FromBit)) > 0))
    FromBit = FromBit + 1
    If FromBit = 8 Then
        If FromPos + 1 > UBound(FromArray) Then
            Do While i < NumBits
                Temp = Temp * 2
                i = i + 1
            Loop
            FromPos = FromPos + 1
            Exit For
        End If
        FromPos = FromPos + 1
    FromBit = 0
    End If
Next
ReadBitsFromArray = Temp
End Function

Private Sub AddmCharToArray(ToArray() As Byte, ToPos As Long, mChar As Byte)
If ToPos > UBound(ToArray) Then ReDim Preserve ToArray(ToPos + 500)
ToArray(ToPos) = mChar
ToPos = ToPos + 1
End Sub

do..exit做..

Do
    mChar = 0
    For i = 0 To 7
        Index = (1 * (2 ^ i)) - 1 + mChar
        RangValue = HighValue - LowValue
        MidValue = LowValue + (RangValue * (Zero(Index) / (One(Index) + Zero(Index))))
        If MidValue = LowValue Then MidValue = MidValue + 1
        If MidValue = HighValue - 1 Then MidValue = MidValue - 1
        If Value >= MidValue Then
            mChar = (2 * mChar) + 1
            LowValue = MidValue
            One(Index) = One(Index) + 1
        Else
            mChar = 2 * mChar
            HighValue = MidValue
            Zero(Index) = Zero(Index) + 1
        End If

        Do While (HighValue And TopBit) = (LowValue And TopBit) Or LowValue > HighValue - 255
            If InpPos <= UBound(ByteArray) Then
                Value = (Value And (TopBit - 1)) * 2 + ReadBitsFromArray(ByteArray, InpPos, InBitPos, 1)
                HighValue = (HighValue And (TopBit - 1)) * 2 + 1
                LowValue = (LowValue And (TopBit - 1)) * 2
                If LowValue >= HighValue Then HighValue = (2 ^ MaxBits) - 1
            Else
                EOF_State = True
                Exit Do
            End If
        Loop
        If EOF_State = True Then Exit Do
    Next
    Call AddmCharToArray(OutStream, OutPos, mChar)
Loop

对不起,我不能写好英语.