And what is the type of bmpFile? I guess what I'm getting at here is
that your real issue is more the problem of "How do I serialize a
HBITMAP structure to an array of bytes and restore it." more than "how
do I save it to the database". I think if you can take the database
out of the picture for a moment and simply get the saving of the
bitmap to an array of bytes in memory and re-loading working, you're
going to be fine.
On Fri, Aug 29, 2008 at 2:38 PM, Jared Miller <[EMAIL PROTECTED]> wrote:
> Yes I am able to do that. I fill out the BITMAPFILEHEADER and
> BITMAPINFOHEADER information for the image, and then I do this:
>
> bmpFile.Write(&bitmapfileheader, sizeof(BITMAPFILEHEADER));
> bmpFile.Write(&bitmapinfoheader, sizeof(BITMAPINFOHEADER));
> bmpFile.Write(pbyBitmap, size); //pbyBitmap is the actual byte data
>
> This has worked correctly for me. I can load it from the file using
> SHLoadDIBitmap().
>
> That is the way I wrote it to a .bmp file.
>
> Jeffrey Becker wrote:
>> Are you able to load and save the bitmap to a file?
>>
>> On Fri, Aug 29, 2008 at 2:13 PM, Jared Miller <[EMAIL PROTECTED]> wrote:
>>
>>> Hello,
>>>
>>> I am having trouble figuring out how to successfully write an image to the
>>> SQLite database as a Blob, using C++.
>>>
>>> I have an HBITMAP that I would like to be able to store to and retrieve
>>> from the DB. If I understand what I have read correctly, I am supposed to
>>> write out the actual byte data to the DB. Here is what I have done so far.
>>>
>>> I pass in pbyBitmap as the bmBytes parameter to this function:
>>> ImportPageImage(CPage* pPage, BYTE* bmBytes, DWORD bmSize), which calls the
>>> code below. . .
>>>
>>> //prepare query
>>> static const WCHAR tblInsertBlob[] = _T("Insert into [tblBlob] ([Data])
>>> values (?)");
>>> SQL_HANDLE blobHandle = m_pSqliteDB->PrepareQuery16(tblInsertBlob); //calls
>>> sqlite3_prepare16()
>>>
>>> //bind blob
>>> m_pSqliteDB->BindBlob(blobHandle, 1, (void *)bmBytes, bmSize); //calls
>>> sqlite3_bind_blob (bmBytes is the pData param)
>>>
>>> Then I call StepQuery to execute it, and then I close the query.
>>> sqlite3_bind_blob() returns SQLITE_OK when I run it, so it does not seem to
>>> be encountering an error there.
>>>
>>> Something apparently gets written to the database, but it does not seem to
>>> be correct. When I try to retrieve and display my image, it is all black
>>> (which is how bitmaps look when there is no data).
>>>
>>> I think that the problem is coming from writing the BLOB to the database,
>>> but I am not entirely sure. Just in case it is getting written properly and
>>> I am not reading it from the database correctly, I will show you how I
>>> pulled it from the DB.
>>>
>>> //prepare blob
>>> sqlite3_blob* pBlob = NULL;
>>> sqlite3_blob_open(m_sqliteDB, "main", "tblBlob", "Data", iBlobID, FALSE,
>>> &pBlob);
>>>
>>> BLOB_HANDLE hBlob = pBlob;
>>> int size = sqlite3_blob_bytes(hBlob); //works correctly, returns 998058
>>> BYTE* pBuffer = g_MemMgr.AllocDataBuffer(size);
>>>
>>> sqlite3_blob_read(hBlob, pBuffer, size, 0); //returns SQLITE_OK
>>> sqlite3_blob_close(hBlob);
>>>
>>> I then try to make a bitmap out of the bytes in pBuffer, but when I do, it
>>> turns out all black (as I mentioned earlier).
>>>
>>> Do I have the concept correct? And if so, what part of my current code
>>> should I change to be able to use my DB to store image data?
>>>
>>> Thanks a lot.
>>>
>>>
>>>
>>> _______________________________________________
>>> sqlite-users mailing list
>>> sqlite-users@sqlite.org
>>> http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
>>>
>>>
>> _______________________________________________
>> sqlite-users mailing list
>> sqlite-users@sqlite.org
>> http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
>>
>>
>>
>
> _______________________________________________
> sqlite-users mailing list
> sqlite-users@sqlite.org
> http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
>
_______________________________________________
sqlite-users mailing list
sqlite-users@sqlite.org
http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
