adoblobdlg.cpp

用ADO进行数据访问的例子

	m_bNewUser = TRUE;
	UpdateData(FALSE);
	DestroyPhoto();
	Invalidate();
}

//////////////删除用户//////////////
void CADOBlobDlg::OnDeleteUser() 
{	
	//theApp.m_pConnection->BeginTrans();
	m_pRecordset->Delete(adAffectCurrent);
	AfxMessageBox("waiting...");
	
	//theApp.m_pConnection->RollbackTrans();
	if(m_pRecordset->adoEOF)
		m_pRecordset->MoveLast();
	ResetControls();
	m_buttonDeleteUser.EnableWindow(FALSE);
	ReadData();
	Invalidate();
}

void CADOBlobDlg::OnChangeUsername()
{
	m_bModify = TRUE;
	m_buttonSaveInfo.EnableWindow();
}

void CADOBlobDlg::OnChangeOld() 
{
	m_bModify = TRUE;
	m_buttonSaveInfo.EnableWindow();
}

////////////////保存用户信息/////////////////
void CADOBlobDlg::OnSaveinfo() 
{
	char sstime[30];
	if(!m_bModify) return;
	UpdateData();
	if(m_pBMPBuffer == NULL || m_hPhotoBitmap == NULL || m_UserName == "" || m_Old == "")
	{
		AfxMessageBox("您没有提供完整的用户信息。\r\n这些信息包括:用户名、年龄、照片");
		return;
	}
	m_buttonSaveInfo.EnableWindow(FALSE);
	char			*pBuf = m_pBMPBuffer;
	VARIANT			varBLOB;
	SAFEARRAY		*psa;
    SAFEARRAYBOUND	rgsabound[1];
	BOOL h;

	if(m_bNewUser){
        //m_pRecordset->get_EditMode(adEditAdd
	//	m_pRecordset->put_LockType(adLockPessimistic);
		h=m_pRecordset->Supports(adAddNew);
		if(!h)
			::AfxMessageBox("not support AddNew!",MB_OK,0);
		else 
			::AfxMessageBox("OK! support AddNew!",MB_OK,0);
		m_pRecordset->AddNew();
	}


	gettime((char ** )sstime);
	m_pRecordset->PutCollect("username",_variant_t(m_UserName));
	//m_pRecordset->PutCollect("old",atol(m_Old));
	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("photo")->AppendChunk(varBLOB);
	}
	gettime((char ** )sstime);
	
	m_pRecordset->Update();
	gettime((char ** )sstime);
	AfxMessageBox("OK! Finished!!",MB_OK,0);
	
	
	m_buttonDeleteUser.EnableWindow();
	ResetControls();
	m_bNewUser = FALSE;
	m_bModify = FALSE;
}

///////////选择BMP文件并加载到内存/////////////
void CADOBlobDlg::OnSelectphoto() 
{
	static char BASED_CODE szFilter[] = "BMP Files (*.bmp)|*.bmp|All Files (*.*)|*.*||";
	CFileDialog dlg(TRUE,"BMP",NULL,  OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT,szFilter);
	if(dlg.DoModal() == IDOK)
	{
		CString pathname = dlg.GetPathName();
		DestroyPhoto();
		LoadBMPFile(pathname);
		m_hPhotoBitmap = BufferToHBITMAP();
		m_bModify = TRUE;
		m_buttonSaveInfo.EnableWindow();
		Invalidate();
	}
}

/////////////清除分配的对象/////////////
void CADOBlobDlg::DestroyPhoto()
{
	if(m_hPhotoBitmap)
	{
		DeleteObject(m_hPhotoBitmap);
		m_hPhotoBitmap = NULL;
	}
	if(m_pBMPBuffer)
	{
		delete m_pBMPBuffer;
		m_pBMPBuffer = NULL;
	}
}

/////////////加载BMP文件到内存//////////////
BOOL CADOBlobDlg::LoadBMPFile(const char *pBMPPathname)
{
	CFile file;
	if( !file.Open( pBMPPathname, CFile::modeRead) )
		return FALSE;
	m_nFileLen = file.GetLength();
	m_pBMPBuffer = new char[m_nFileLen + 1];
	if(!m_pBMPBuffer)
		return FALSE;
	if(file.ReadHuge(m_pBMPBuffer,m_nFileLen) != m_nFileLen)
		return FALSE;
	return TRUE;
}

///////////将内存中的BMP文件内容转换到HBITMAP///////
HBITMAP CADOBlobDlg::BufferToHBITMAP()
{
	HBITMAP				hBmp;
	LPSTR				hDIB,lpBuffer = m_pBMPBuffer;
	LPVOID				lpDIBBits;
	BITMAPFILEHEADER	bmfHeader;
	DWORD				bmfHeaderLen;

	bmfHeaderLen = sizeof(bmfHeader);
	strncpy((LPSTR)&bmfHeader,(LPSTR)lpBuffer,bmfHeaderLen);
	if (bmfHeader.bfType != ((WORD) ('M' << 8) | 'B')) return NULL;
	hDIB = lpBuffer + bmfHeaderLen;
	BITMAPINFOHEADER &bmiHeader = *(LPBITMAPINFOHEADER)hDIB ;
	BITMAPINFO &bmInfo = *(LPBITMAPINFO)hDIB ;
	int nColors = bmiHeader.biClrUsed ? bmiHeader.biClrUsed : 1 << bmiHeader.biBitCount; 
	if( bmInfo.bmiHeader.biBitCount > 8 )
		lpDIBBits = (LPVOID)((LPDWORD)(bmInfo.bmiColors + bmInfo.bmiHeader.biClrUsed) + 
			((bmInfo.bmiHeader.biCompression == BI_BITFIELDS) ? 3 : 0));
	else
		lpDIBBits = (LPVOID)(bmInfo.bmiColors + nColors);
	CClientDC dc(this);
	hBmp = CreateDIBitmap(dc.m_hDC,&bmiHeader,CBM_INIT,lpDIBBits,&bmInfo,DIB_RGB_COLORS);
	return hBmp;
}


BOOL CADOBlobDlg::DestroyWindow() 
{
	DestroyPhoto();
	return CDialog::DestroyWindow();
}

//////////////下一个用户信息///////////////
void CADOBlobDlg::OnNextUser() 
{
	if(m_bModify)///假如当前记录改动过，则保存
		OnSaveinfo();
	m_pRecordset->MoveNext();
	if(m_pRecordset->adoEOF)
		m_pRecordset->MoveLast();
	ReadData();
	ResetControls();
	Invalidate();
}

/////////////上一个用户信息/////////////////
void CADOBlobDlg::OnPreviousUser() 
{
	if(m_bModify)///假如当前记录改动过，则保存
		OnSaveinfo();
	m_pRecordset->MovePrevious();
	if(m_pRecordset->BOF)
		m_pRecordset->MoveFirst();
	ReadData();
	ResetControls();
	Invalidate();
}

////////////////判断是否是最后一个记录//////////////
BOOL CADOBlobDlg::LastRecord()
{
	if(m_pRecordset->adoEOF)
	{
		m_editUserName.EnableWindow(FALSE);
		m_editOld.EnableWindow(FALSE);
		m_buttonSelectPhoto.EnableWindow(FALSE);
		return TRUE;
	}
	m_pRecordset->MoveNext();
	if(m_pRecordset->adoEOF)
	{
		m_pRecordset->MovePrevious();
		return TRUE;
	}
	else
	{
		m_pRecordset->MovePrevious();
		return FALSE;
	}

}

////////////////判断是否是第一个记录////////////////
BOOL CADOBlobDlg::FirstRecord()
{
	if(m_pRecordset->BOF)
	{
		m_editUserName.EnableWindow(FALSE);
		m_editOld.EnableWindow(FALSE);
		m_buttonSelectPhoto.EnableWindow(FALSE);
		return TRUE;
	}
	m_pRecordset->MovePrevious();
	if(m_pRecordset->BOF)
	{
		m_pRecordset->MoveFirst();
		return TRUE;
	}
	else
	{
		m_pRecordset->MoveNext();
		return FALSE;
	}
}

void CADOBlobDlg::ResetControls()
{
	BOOL IsFirstRecord = FirstRecord();
	BOOL IsLastRecord = LastRecord();
	m_buttonPreviousUser.EnableWindow(!IsFirstRecord);
	m_buttonNextUser.EnableWindow(!IsLastRecord);
}

void CADOBlobDlg::OnUpdate() 
{
	char sstime[30];
	if(!m_bModify) return;
	UpdateData();
	if(m_pBMPBuffer == NULL || m_hPhotoBitmap == NULL || m_UserName == "" || m_Old == "")
	{
		AfxMessageBox("您没有提供完整的用户信息。\r\n这些信息包括:用户名、年龄、照片");
		return;
	}
	m_buttonSaveInfo.EnableWindow(FALSE);
	char			*pBuf = m_pBMPBuffer;
	VARIANT			varBLOB;
	SAFEARRAY		*psa;
    SAFEARRAYBOUND	rgsabound[1];
	BOOL h;

	if(m_bNewUser){
		if(!h)
			::AfxMessageBox("not support AddNew!",MB_OK,0);
		else 
			::AfxMessageBox("OK! support AddNew!",MB_OK,0);
//		m_pRecordset->AddNew();
	}


	gettime((char ** )sstime);
	m_pRecordset->PutCollect("username",_variant_t(m_UserName));
	//m_pRecordset->PutCollect("old",atol(m_Old));
	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("photo")->AppendChunk(varBLOB);
	}
	gettime((char ** )sstime);
	
	m_pRecordset->Update();
	gettime((char ** )sstime);
	AfxMessageBox("OK!Update Finished!!",MB_OK,0);
	
	
	m_buttonDeleteUser.EnableWindow();
	ResetControls();
	m_bNewUser = FALSE;
	m_bModify = FALSE;
	
}