leadergl
12-02-2006, 22:16
Salve gente, ho scritto un paio di piccole procedure in VB6 per permettermi di utilizzare le dll zlib per la compressione/decompressione di files ma ho un piccolo problema ovvero il VB nel momento di eseguire l'operazione mi dice:
"Bad DLL calling convention" e non riesco a capire il perchè, cmq mi evidenzia questa riga:
Result = compress(DestBuffer(0), DestBufferSize, SourceBuffer(0), SourceBufferSize)
questo è il codice che ho scritto:
Option Explicit
' VALORI RITORNATI DALLE FUNZIONI DI COMPRESSIONE/DECOMPRESSIONE
Public Enum RETURN_VALUE
Z_OK = 0
Z_STREAM_END = 1
Z_NEED_DICT = 2
Z_ERRNO = -1
Z_STREAM_ERROR = -2
Z_DATA_ERROR = -3
Z_MEM_ERROR = -4
Z_BUFF_ERROR = -5
Z_VERSION_ERROR = -6
End Enum
' LIVELLI DI COMPRESSIONE
Public Enum COMPRESSION_LEVEL
Z_NO_COMPRESSION = 0
Z_BEST_SPEED = 1
Z_BEST_COMPRESSION = 9
Z_DEFAULT_COMPRESSION = -1
Z_NO_INFO = -2
End Enum
' DICHIARAZIONE FUNZIONI
Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" (hpvDest As Any, hpvSource As Any, ByVal cbCopy As Long)
Private Declare Function compress Lib "zlib.dll" (dest As Any, destLen As Any, src As Any, ByVal srcLen As Long) As RETURN_VALUE
Private Declare Function compress2 Lib "zlib.dll" (dest As Any, destLen As Any, src As Any, ByVal srcLen As Long, ByVal level As Integer) As RETURN_VALUE
Private Declare Function uncompress Lib "zlib.dll" (dest As Any, destLen As Any, src As Any, ByVal srcLen As Long) As RETURN_VALUE
' ================================================================
' FUNZIONI INTERFACCIAMENTO CON ZLIB
' ================================================================
' Ritorna la grandezza del file compresso
Private Function CompressData(ByRef SourceBuffer() As Byte, Optional CompressionLevel As COMPRESSION_LEVEL = Z_NO_INFO) As Long
'ANSI C: int compress (Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen);
'ANSI C: int compress2 (Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen, int level);
Dim DestBuffer() As Byte
Dim DestBufferSize As Long
Dim SourceBufferSize As Long
Dim Result As RETURN_VALUE
SourceBufferSize = UBound(SourceBuffer()) + 1
DestBufferSize = SourceBufferSize + (SourceBufferSize * 0.01) + 12
Retry:
ReDim DestBuffer(DestBufferSize)
If (CompressionLevel = Z_NO_INFO) Then
Result = compress(DestBuffer(0), DestBufferSize, SourceBuffer(0), SourceBufferSize)
Else
Result = compress2(DestBuffer(0), DestBufferSize, SourceBuffer(0), SourceBufferSize, CompressionLevel)
End If
'Copio il DestBuffer (che verrà eliminato) in SourceBuffer (ridimensionandolo)
ReDim SourceBuffer(DestBufferSize)
CopyMemory SourceBuffer(0), DestBuffer(0), DestBufferSize
If Result = Z_OK Then
' Ritorno la grandezza del buffer di output
CompressData = DestBufferSize
ElseIf Result = Z_BUFF_ERROR Then
' Buffer di destinazione troppo piccolo
' Incremento il buffer e riprovo
DestBufferSize = 2 * DestBufferSize
GoTo Retry
ElseIf Result = Z_MEM_ERROR Then
' Memoria insufficiente
' Esco dalla funzione ritornando Z_MEM_ERROR
CompressData = Z_MEM_ERROR
End If
End Function
cosa c'è di sbagliato nel mio codice?
"Bad DLL calling convention" e non riesco a capire il perchè, cmq mi evidenzia questa riga:
Result = compress(DestBuffer(0), DestBufferSize, SourceBuffer(0), SourceBufferSize)
questo è il codice che ho scritto:
Option Explicit
' VALORI RITORNATI DALLE FUNZIONI DI COMPRESSIONE/DECOMPRESSIONE
Public Enum RETURN_VALUE
Z_OK = 0
Z_STREAM_END = 1
Z_NEED_DICT = 2
Z_ERRNO = -1
Z_STREAM_ERROR = -2
Z_DATA_ERROR = -3
Z_MEM_ERROR = -4
Z_BUFF_ERROR = -5
Z_VERSION_ERROR = -6
End Enum
' LIVELLI DI COMPRESSIONE
Public Enum COMPRESSION_LEVEL
Z_NO_COMPRESSION = 0
Z_BEST_SPEED = 1
Z_BEST_COMPRESSION = 9
Z_DEFAULT_COMPRESSION = -1
Z_NO_INFO = -2
End Enum
' DICHIARAZIONE FUNZIONI
Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" (hpvDest As Any, hpvSource As Any, ByVal cbCopy As Long)
Private Declare Function compress Lib "zlib.dll" (dest As Any, destLen As Any, src As Any, ByVal srcLen As Long) As RETURN_VALUE
Private Declare Function compress2 Lib "zlib.dll" (dest As Any, destLen As Any, src As Any, ByVal srcLen As Long, ByVal level As Integer) As RETURN_VALUE
Private Declare Function uncompress Lib "zlib.dll" (dest As Any, destLen As Any, src As Any, ByVal srcLen As Long) As RETURN_VALUE
' ================================================================
' FUNZIONI INTERFACCIAMENTO CON ZLIB
' ================================================================
' Ritorna la grandezza del file compresso
Private Function CompressData(ByRef SourceBuffer() As Byte, Optional CompressionLevel As COMPRESSION_LEVEL = Z_NO_INFO) As Long
'ANSI C: int compress (Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen);
'ANSI C: int compress2 (Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen, int level);
Dim DestBuffer() As Byte
Dim DestBufferSize As Long
Dim SourceBufferSize As Long
Dim Result As RETURN_VALUE
SourceBufferSize = UBound(SourceBuffer()) + 1
DestBufferSize = SourceBufferSize + (SourceBufferSize * 0.01) + 12
Retry:
ReDim DestBuffer(DestBufferSize)
If (CompressionLevel = Z_NO_INFO) Then
Result = compress(DestBuffer(0), DestBufferSize, SourceBuffer(0), SourceBufferSize)
Else
Result = compress2(DestBuffer(0), DestBufferSize, SourceBuffer(0), SourceBufferSize, CompressionLevel)
End If
'Copio il DestBuffer (che verrà eliminato) in SourceBuffer (ridimensionandolo)
ReDim SourceBuffer(DestBufferSize)
CopyMemory SourceBuffer(0), DestBuffer(0), DestBufferSize
If Result = Z_OK Then
' Ritorno la grandezza del buffer di output
CompressData = DestBufferSize
ElseIf Result = Z_BUFF_ERROR Then
' Buffer di destinazione troppo piccolo
' Incremento il buffer e riprovo
DestBufferSize = 2 * DestBufferSize
GoTo Retry
ElseIf Result = Z_MEM_ERROR Then
' Memoria insufficiente
' Esco dalla funzione ritornando Z_MEM_ERROR
CompressData = Z_MEM_ERROR
End If
End Function
cosa c'è di sbagliato nel mio codice?