请高手帮忙看下VB中的数据库图像转换有关问题
请高手帮忙看下VB中的数据库图像转换问题
在http://www.anilsoft.com/total.rar中一MDB数据库中存有JPG文件(数据可能经过一定变换)，我采用以下方法保存为文件均不能正常显示，请高手帮忙看下该怎么弄呀，谢谢啦
1.jpg保存后文件16进制数据为：FF 00 D8 00 FF 00 E0 00 00 00 10 00 4A 00 46 00 49 ......
2.jpg保存后文件16进制数据为：3F 3F 3F A8 ......
而JPG文件的应该为：FF D8 FF E0 00 10 4A 46 49 ......
请教高手些该如何转换才能保存为正常的图像文件，数据库可通过开始的地址下载
------解决思路----------------------
------解决思路----------------------
你得自己找出转换规律啊。
------解决思路----------------------
没准是base64编码。
在http://www.anilsoft.com/total.rar中一MDB数据库中存有JPG文件(数据可能经过一定变换)，我采用以下方法保存为文件均不能正常显示，请高手帮忙看下该怎么弄呀，谢谢啦
Private Sub Command4_Click()
Dim cn As New ADODB.Connection
Dim rs As New ADODB.Recordset
Dim i As Long
Dim b() As Byte
cn.Open "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=E:\total.mdb;Persist Security Info=False"
rs.Open "Schede", cn, adOpenKeyset, adLockReadOnly, adCmdTable
i = rs("Image").ActualSize
b = rs("Image").GetChunk(i)
Open "e:\1.jpg" For Binary As #1
Put #1, , b
Close #1
rs.Close
cn.Close
End Sub
Private Sub Command5_Click()
Dim cn As New ADODB.Connection
Dim rs As New ADODB.Recordset
Dim i As Long
Dim b() As Byte
cn.Open "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=E:\total.mdb;Persist Security Info=False"
rs.Open "Schede", cn, adOpenKeyset, adLockReadOnly, adCmdTable
i = rs("Image").ActualSize
b = rs("Image").GetChunk(i)
Open "e:\2.jpg" For Binary As #1
Put #1, , CStr(b)
Close #1
rs.Close
cn.Close
End Sub
1.jpg保存后文件16进制数据为：FF 00 D8 00 FF 00 E0 00 00 00 10 00 4A 00 46 00 49 ......
2.jpg保存后文件16进制数据为：3F 3F 3F A8 ......
而JPG文件的应该为：FF D8 FF E0 00 10 4A 46 49 ......
请教高手些该如何转换才能保存为正常的图像文件，数据库可通过开始的地址下载
------解决思路----------------------
Dim b() As Byte
Dim c() As Byte
b = rs("Image").GetChunk(i) 'FF 00 D8 00 FF 00 E0 00 00 00 10 00 4A 00 46 00 49
Redim c( ((UBound(b)+1)\2) - 1)
For i=0 To UBound(c)
c(i) = b(i*2)
Next
'c 成了 FF D8 FF E0 00 10 4A 46 49，把它写入文件。
------解决思路----------------------
你得自己找出转换规律啊。
------解决思路----------------------
没准是base64编码。
#pragma comment(lib,"crypt32")
#include <windows.h>
#include <stdio.h>
#include <tchar.h>
//+-------------------------------------------------------------------------
// convert formatted string to binary
// If cchString is 0, then pszString is NULL terminated and
// cchString is obtained via strlen() + 1.
// dwFlags defines string format
// if pbBinary is NULL, *pcbBinary returns the size of required memory
// *pdwSkip returns the character count of skipped strings, optional
// *pdwFlags returns the actual format used in the conversion, optional
//--------------------------------------------------------------------------
BOOL
WINAPI
CryptStringToBinaryA(
IN LPCSTR pszString,
IN DWORD cchString,
IN DWORD dwFlags,
IN BYTE *pbBinary,
IN OUT DWORD *pcbBinary,
OUT DWORD *pdwSkip, //OPTIONAL
OUT DWORD *pdwFlags //OPTIONAL
);
//+-------------------------------------------------------------------------
// convert formatted string to binary
// If cchString is 0, then pszString is NULL terminated and
// cchString is obtained via strlen() + 1.
// dwFlags defines string format
// if pbBinary is NULL, *pcbBinary returns the size of required memory
// *pdwSkip returns the character count of skipped strings, optional
// *pdwFlags returns the actual format used in the conversion, optional
//--------------------------------------------------------------------------
BOOL
WINAPI
CryptStringToBinaryW(
IN LPCWSTR pszString,
IN DWORD cchString,
IN DWORD dwFlags,
IN BYTE *pbBinary,
IN OUT DWORD *pcbBinary,
OUT DWORD *pdwSkip, //OPTIONAL
OUT DWORD *pdwFlags //OPTIONAL
);
#ifdef UNICODE
#define CryptStringToBinary CryptStringToBinaryW
#else
#define CryptStringToBinary CryptStringToBinaryA
#endif // !UNICODE
//+-------------------------------------------------------------------------
// convert binary to formatted string
// dwFlags defines string format
// if pszString is NULL, *pcchString returns the size of required memory in byte
//--------------------------------------------------------------------------
BOOL
WINAPI
CryptBinaryToStringA(
IN CONST BYTE *pbBinary,
IN DWORD cbBinary,
IN DWORD dwFlags,
IN LPSTR pszString,
IN OUT DWORD *pcchString
);
//+-------------------------------------------------------------------------
// convert binary to formatted string
// dwFlags defines string format
// if pszString is NULL, *pcchString returns the size of required memory in byte
//--------------------------------------------------------------------------
BOOL
WINAPI
CryptBinaryToStringW(
IN CONST BYTE *pbBinary,
IN DWORD cbBinary,
IN DWORD dwFlags,
IN LPWSTR pszString,
IN OUT DWORD *pcchString
);
#ifdef UNICODE
#define CryptBinaryToString CryptBinaryToStringW
#else
#define CryptBinaryToString CryptBinaryToStringA
#endif // !UNICODE
// dwFlags has the following defines
#define CRYPT_STRING_BASE64HEADER 0x00000000
#define CRYPT_STRING_BASE64 0x00000001
#define CRYPT_STRING_BINARY 0x00000002
#define CRYPT_STRING_BASE64REQUESTHEADER 0x00000003
#define CRYPT_STRING_HEX 0x00000004
#define CRYPT_STRING_HEXASCII 0x00000005
#define CRYPT_STRING_BASE64_ANY 0x00000006
#define CRYPT_STRING_ANY 0x00000007
#define CRYPT_STRING_HEX_ANY 0x00000008
#define CRYPT_STRING_BASE64X509CRLHEADER 0x00000009
#define CRYPT_STRING_HEXADDR 0x0000000a
#define CRYPT_STRING_HEXASCIIADDR 0x0000000b
#define CRYPT_STRING_NOCR 0x80000000
// CryptBinaryToString uses the following flags
// CRYPT_STRING_BASE64HEADER - base64 format with certificate begin
// and end headers
// CRYPT_STRING_BASE64 - only base64 without headers
// CRYPT_STRING_BINARY - pure binary copy
// CRYPT_STRING_BASE64REQUESTHEADER - base64 format with request begin
// and end headers
// CRYPT_STRING_BASE64X509CRLHEADER - base64 format with x509 crl begin
// and end headers
// CRYPT_STRING_HEX - only hex format
// CRYPT_STRING_HEXASCII - hex format with ascii char display
// CRYPT_STRING_HEXADDR - hex format with address display
// CRYPT_STRING_HEXASCIIADDR - hex format with ascii char and address display
//
// CryptBinaryToString accepts CRYPT_STRING_NOCR or'd into one of the above.
// When set, line breaks contain only LF, instead of CR-LF pairs.
// CryptStringToBinary uses the following flags
// CRYPT_STRING_BASE64_ANY tries the following, in order:
// CRYPT_STRING_BASE64HEADER
// CRYPT_STRING_BASE64
// CRYPT_STRING_ANY tries the following, in order:
// CRYPT_STRING_BASE64_ANY
// CRYPT_STRING_BINARY -- should always succeed
// CRYPT_STRING_HEX_ANY tries the following, in order:
// CRYPT_STRING_HEXADDR
// CRYPT_STRING_HEXASCIIADDR
// CRYPT_STRING_HEXASCII
// CRYPT_STRING_HEX
char *flags[12]={
"CRYPT_STRING_BASE64HEADER",
"CRYPT_STRING_BASE64",
"CRYPT_STRING_BINARY",
"CRYPT_STRING_BASE64REQUESTHEADER",
"CRYPT_STRING_HEX",
"CRYPT_STRING_HEXASCII",
"CRYPT_STRING_BASE64_ANY",
"CRYPT_STRING_ANY",
"CRYPT_STRING_HEX_ANY",
"CRYPT_STRING_BASE64X509CRLHEADER",
"CRYPT_STRING_HEXADDR",
"CRYPT_STRING_HEXASCIIADDR",
};
#define MAXC 1024
BYTE b[22]={
0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0A,0x0B,0x0C,0x0D,0x0E,0x0F,
0x41,0x42,0xB0,0xA1,0x4A,0x55,
};
BOOL r;
DWORD len,dwFlags;
TCHAR s[MAXC];
int _tmain() {
_tprintf(_T("API CryptBinaryToString in crypt32.dll Demonstration:\n"));
for (dwFlags=0;dwFlags<12;dwFlags++) {
if (dwFlags==2
------解决思路----------------------
dwFlags==6
------解决思路----------------------
dwFlags==7
------解决思路----------------------
dwFlags==8) continue;
r=CryptBinaryToString(b,22,dwFlags,NULL,&len);
if (!r) {
_tprintf(_T("CryptBinaryToString error!\n"));
return 1;
}
if (len>MAXC) {
_tprintf(_T("%d==len>MAXC==%d!\n"),len,MAXC);
return 2;
}
r=CryptBinaryToString(b,22,dwFlags,s,&len);
if (!r) {
_tprintf(_T("CryptBinaryToString error!\n"));
return 3;
}
_tprintf(_T("\n%s:[\n%s]\n"),flags[dwFlags],s);
}
return 0;
}
//API CryptBinaryToString in crypt32.dll Demonstration:
//
//CRYPT_STRING_BASE64HEADER:[
//-----BEGIN CERTIFICATE-----
//AAECAwQFBgcICQoLDA0OD0FCsKFKVQ==
//-----END CERTIFICATE-----
//]
//
//CRYPT_STRING_BASE64:[
//AAECAwQFBgcICQoLDA0OD0FCsKFKVQ==
//]
//
//CRYPT_STRING_BASE64REQUESTHEADER:[
//-----BEGIN NEW CERTIFICATE REQUEST-----
//AAECAwQFBgcICQoLDA0OD0FCsKFKVQ==
//-----END NEW CERTIFICATE REQUEST-----
//]
//
//CRYPT_STRING_HEX:[
// 00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f
// 41 42 b0 a1 4a 55
//]
//
//CRYPT_STRING_HEXASCII:[
// 00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f ................
// 41 42 b0 a1 4a 55 AB..JU
//]
//
//CRYPT_STRING_BASE64X509CRLHEADER:[
//-----BEGIN X509 CRL-----
//AAECAwQFBgcICQoLDA0OD0FCsKFKVQ==
//-----END X509 CRL-----
//]
//
//CRYPT_STRING_HEXADDR:[
//0000 00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f
//0010 41 42 b0 a1 4a 55
//]
//
//CRYPT_STRING_HEXASCIIADDR:[
//0000 00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f ................
//0010 41 42 b0 a1 4a 55 AB..JU
//]
//