VC uses ADO to access and display jpg/BMP bitmap files

On Saturday and today, the storage and display of images in the database were realized. Although the time was a little long, it was still realized. The following documents are useful.

Http://hi.baidu.com/%B0%A2%B3%ACyuch/blog/item/3a0d0845980f0744500ffe5b.html

Step 1: First, open a bitmap file. The controls used here use the picture control, which is the one on the right of the control icon. Change the ID number to idc_picture and define two member variables.
Char * m_char; // image file pointer
DWORD m_nfilelen; // image Length
Then write in the function:
Cfiledialog DLG (true, null, null, 0, "photo files (*. jpg; *. BMP) | *. jpg; *. BMP |", this );
If (idok = DLG. domodal ())
{
M_path = DLG. getpathname ();
M_bool = true;
}
Cwnd * pwnd = getdlgitem (idc_picture );
Crect rect;
Pwnd-> getclientrect (& rect );
CDC * PDC = pwnd-> getdc ();
Cfilestatus fstatus;
Cfile file;
Long CB;
Bool m_tm = false;
Ipicture * PPIC;
Cstring m_spath;
If (file. Open (m_path, cfile: moderead) & file. getstatus (m_path, fstatus) & (cb = fstatus. m_size )! =-1 ))

{

If (CB> 1048576) // you can set the image size here
{
M_tm = false;
MessageBox ("image cannot exceed 1 MB", "prompt! ");
}
Else
{

M_nfilelen = (uint) Cb;
Hglobal = globalalloc (gmem_moveable, CB );
Lpvoid pvdata = NULL;
If (hglobal! = NULL)
{
If (pvdata = globallock (hglobal ))! = NULL)
{
File. readhuge (pvdata, CB );
M_char = (char *) pvdata;
Globalunlock (hglobal );
Createstreamonhglobal (hglobal, true, & PSTM );
M_tm = true;
// M_bool = true;
}
Else
Afxmessagebox ("not an image file! ");
}
Else
Afxmessagebox ("memory application failed! ");

}
}
Else
Afxmessagebox ("not an image file! ");
If (m_tm)
{
Succeeded (oleloadpicture (PSTM, fstatus. m_size, true, iid_ipicture, (lpvoid *) & PPIC ));
Ole_xsize_himetric hmwidth;
Ole_ysize_himetric hmheight;
PPIC-> get_width (& hmwidth );
PPIC-> get_height (& hmheight );
If (failed (PPIC-> render (* PDC, 0, 0, rect. Width (), rect. Height (), 0, hmheight, hmwidth,-hmheight, null )))

Afxmessagebox ("rendering image failed! ");
PPIC-> release ();
}
There is also a small problem here, that is, when the window is re-painted, the image will disappear, you can add the above Code to the onpaint function;
The connection is to save the file (for how to access the database, you can see "access the database with ADO" in my space "):
Change the type of the photo field to Ole type in the Access Database (change to the photo type in the SQL database ).
M_recordset-> addnew ();
Char * pbuf = m_char; // pass the pointer of the image to pbuf.
Variant varblob;
Safearray * PSA;
Safearraybound rgsabound [1];
If (pbuf)
{
Rgsabound [0]. llbound = 0;
Rgsabound [0]. celements = m_nfilelen;
PSA = safearraycreate (vt_ui1, 1, rgsabound );
For (long I = 0; I <(long) m_nfilelen; I ++)
Safearrayputelement (PSA, & I, pbuf ++ );
Varblob. Vt = vt_array | vt_ui1;
Varblob. parray = psa;
M_precordset-> getfields ()-> getitem ("")-> AppendChunk (varblob );
}
M_precordset-> Update ();

The next step is to extract the image from the database, add the picture control in the displayed dialog box, change the ID to idc_picture, and then write it in the function:
Istream * PSTM;
Long ldatasize = m_precordset-> getfields ()-> getitem ("")-> actualsize;
If (ldatasize> 0)
{
_ Variant_t varblob;
Varblob = theapp. m_data.m_precordset-> getfields ()-> getitem ("")-> getchunk (ldatasize );

If (varblob. Vt = (vt_array | vt_ui1 ))
{
Char * pbuf = NULL;
Safearrayaccessdata (varblob. parray, (void **) & pbuf );
Hglobal = globalalloc (gmem_moveable, ldatasize );
Lpvoid pvdata = NULL;
If (hglobal! = NULL)
{
If (pvdata = globallock (hglobal ))! = NULL)
{
Memcpy (pvdata, pbuf, ldatasize );
Safearrayunaccessdata (varblob. parray );
Globalunlock (hglobal );
Createstreamonhglobal (hglobal, true, & PSTM );
}
Else
Afxmessagebox ("An error occurred while loading the image! ");
}
Else
Afxmessagebox ("memory application failed! ");

}
Cwnd * pwnd = getdlgitem (idc_picture );
Crect rect;
Pwnd-> getclientrect (& rect );
CDC * PDC = pwnd-> getdc ();
Ipicture * PPIC;
If (succeeded (oleloadpicture (PSTM, ldatasize, true, iid_ipicture, (lpvoid *) & PPIC )))

{
Ole_xsize_himetric hmwidth;
Ole_ysize_himetric hmheight;
PPIC-> get_width (& hmwidth );
PPIC-> get_height (& hmheight );
If (failed (PPIC-> render (* PDC, 0, 0, rect. Width (), rect. Height (), 0, hmheight, hmwidth,-hmheight, null )))

Afxmessagebox ("rendering image failed! ");
PPIC-> release ();
}
}
This will also cause the problem that the image disappears when the window is re-painted. You can write the above function in onpaint. the entire display, accessing and accessing images is complete.

Http://hi.baidu.com/roufei13/blog/item/6528919e0fb23aa4c9eaf4d8.html

Coinitialize (null );

 

_ Connectionptr m_pconnect;

Try

{

// Create a connection object

M_pconnect.createinstance ("ADODB. Connection ");

// Set the connection string, which must be of the BSTR or _ bstr_t type

_ Bstr_t strconnect = "provider = sqloledb.1; Password = 111111; persist Security info = true; user id = sa; initial catalog = picture; Data Source = showfly \ sql2005 ";

M_pconnect-> open (strconnect, "", "", admodeunknown );

}

// Catch exceptions

Catch (_ com_error E)

{

// Display the error message

Afxmessagebox (E. Description ());

}

 

Cfile fileadd;

 

If (fileadd. Open ("F:/20087610203.jpg", cfile: moderead) = 0) // open the file

Return;

 

_ Variant_t varchunk;

 

Long m_nfilelen = fileadd. getlength ();

Byte * m_pbmpbuffer;

M_pbmpbuffer = new byte [m_nfilelen];

 

If (m_pbmpbuffer = NULL)

Return;

Fileadd. Read (m_pbmpbuffer, m_nfilelen );

 

// Add images to the database

_ Recordsetptr m_precordset;

M_precordset.createinstance (_ uuidof (recordset ));

 

Try {

M_precordset-> open (_ variant_t ("DBO. userphoto"), _ variant_t (idispatch *) m_pconnect, true), adopenkeyset, adlockoptimistic, adcmdtable );

}

Catch (_ com_error & E)

{

: MessageBox (null, "The userphoto table cannot be opened! "," Prompt ", mb_ OK | mb_iconwarning );

}

 

Char * pbuf = (char *) m_pbmpbuffer;

Variant varblob;

Safearray * PSA;

Safearraybound rgsabound [1];

 

M_precordset-> addnew (); // Add a new record

M_precordset-> putcollect ("username", _ variant_t ("Xiao Li"); // fill in the username field for the new record

M_precordset-> putcollect ("old", _ variant_t (long) 28); // fill in the old field

If (pbuf)

{

Rgsabound [0]. llbound = 0;

Rgsabound [0]. celements = m_nfilelen;

PSA = safearraycreate (vt_ui1, 1, rgsabound); // create a safearray object

For (long I = 0; I <(long) m_nfilelen; I ++)

Safearrayputelement (PSA, & I, pbuf ++); // Save the binary data that pbuf points to the safearray object PSA

Varblob. Vt = vt_array | vt_ui1; // sets the varblob type to an array of the byte type.

Varblob. parray = psa; // assign a value to the varblob variable

M_precordset-> getfields ()-> getitem ("photo")-> AppendChunk (varblob); // Add BLOB Data

}

M_precordset-> Update (); // save our data to the database

 

 

// Read the image from the database

Long ldatalength = m_precordset-> getfields ()-> getitem (_ variant_t ("photo")-> actualsize;

 

If (ldatalength> 0)

{

_ Variant_t varblob;

Varblob = m_precordset-> getfields ()-> getitem (_ variant_t ("photo")-> getchunk (ldatalength );

 

If (varblob. Vt = (vt_array | vt_ui1) & varblob. VT! = Vt_empty & varblob. VT! = Vt_null)

{

Byte * pbuf = NULL;

Pbuf = (byte *) globalalloc (gmem_fixed, ldatalength );

 

Safearrayaccessdata (varblob. parray, (void **) & pbuf );

 

Cfile OUTFILE ("D:/20087610203.bmp", cfile: modecreate | cfile: modewrite); // create a new file. If the file exists, the length is changed to 0.

OUTFILE. Write (pbuf, ldatalength );

OUTFILE. Close ();

 

Safearrayunaccessdata (varblob. parray );

}

}

M_precordset-> close ();

 

M_pconnect-> close ();

 

: Couninitialize ();

Http://www.cnblogs.com/-clq/archive/2011/08/27/2155342.html