dbdoc.cpp

Visual C++实践与提高-刘刀桂, 孟繁晶编著

// DBDoc.cpp : implementation of the CDBDoc class
//

#include "stdafx.h"
#include "DB.h"

#include "DBDoc.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

/////////////////////////////////////////////////////////////////////////////
// CDBDoc

IMPLEMENT_DYNCREATE(CDBDoc, CDocument)

BEGIN_MESSAGE_MAP(CDBDoc, CDocument)
	//{{AFX_MSG_MAP(CDBDoc)
	ON_COMMAND(IDC_CREATE_TABLE, OnCreateTable)
	ON_COMMAND(IDC_READ_TABLE, OnReadTable)
	ON_COMMAND(IDC_WRITE_TABLE, OnWriteTable)
	ON_UPDATE_COMMAND_UI(IDC_READ_TABLE, OnUpdateReadTable)
	ON_UPDATE_COMMAND_UI(IDC_WRITE_TABLE, OnUpdateWriteTable)
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

// {30DF3430-0266-11cf-BAA6-00AA003E0EED}
static const GUID CLSID_DBSAMPLE =
{ 0x30df3430, 0x266, 0x11cf, { 0xba, 0xa6, 0x0, 0xaa, 0x0, 0x3e, 0xe, 0xed } };

// {30DF3432-0266-11cf-BAA6-00AA003E0EED}
static const GUID IID_IDB =
{ 0x30df3432, 0x266, 0x11cf, { 0xba, 0xa6, 0x0, 0xaa, 0x0, 0x3e, 0xe, 0xed } };


/////////////////////////////////////////////////////////////////////////////
// CDBDoc construction/destruction

CDBDoc::CDBDoc()
{
	m_pDB=NULL;
}

CDBDoc::~CDBDoc()
{
	if (m_pDB) 
	{
		m_pDB->Release();
		m_pDB=NULL;
	}
}

BOOL CDBDoc::OnNewDocument()
{
	if (!CDocument::OnNewDocument())
		return FALSE;
	
	//新建数据库对象
	//m_pDB=new CDB;
	// create a database object through the exported function & class factory object
	IClassFactory *pDBFactory=NULL;
	
	HRESULT hRes;
	hRes=CoGetClassObject(CLSID_DBSAMPLE, CLSCTX_SERVER, NULL, IID_IClassFactory, (void**) &pDBFactory);
	if (FAILED(hRes)) {
		CString csError;
		csError.Format(_T("Error %x obtaining class factory for DB Object!"), hRes);
		AfxMessageBox(csError);
		return FALSE;
		}

	hRes=pDBFactory->CreateInstance(NULL, IID_IDB, (void**) &m_pDB);
	if (FAILED(hRes)) {
		CString csError;
		csError.Format(_T("Error %x creating DB Object!"), hRes);
		AfxMessageBox(csError);
		return FALSE;
		}
	
	pDBFactory->Release(); // do not need the factory anymore

	
	// 初始化数据成员变量
	m_csData="No data yet!"; 
	m_nCount=0;		
	m_nTable=-1;	

	return TRUE;
}



/////////////////////////////////////////////////////////////////////////////
// CDBDoc serialization

void CDBDoc::Serialize(CArchive& ar)
{
	if (ar.IsStoring())
	{
		// TODO: add storing code here
	}
	else
	{
		// TODO: add loading code here
	}
}

/////////////////////////////////////////////////////////////////////////////
// CDBDoc diagnostics

#ifdef _DEBUG
void CDBDoc::AssertValid() const
{
	CDocument::AssertValid();
}

void CDBDoc::Dump(CDumpContext& dc) const
{
	CDocument::Dump(dc);
}
#endif //_DEBUG

/////////////////////////////////////////////////////////////////////////////
// CDBDoc commands

void CDBDoc::OnCreateTable() 
{
	m_pDB->Create(m_nTable, L"Testing");	
	m_nCount=0; // set number of writes to 0 

}

void CDBDoc::OnReadTable() 
{
#ifdef UNICODE
	m_pDB->Read(m_nTable, 0, m_csData.GetBuffer(80));
#else
	WCHAR szuData[80];
	m_pDB->Read(m_nTable, 0, szuData);
	WideCharToMultiByte(CP_ACP, 0, szuData, -1, m_csData.GetBuffer(80), 80, NULL, NULL);
#endif
	m_csData.ReleaseBuffer();
	UpdateAllViews(NULL);
}

void CDBDoc::OnWriteTable() 
{
	m_nCount++;
	CString csText;
	csText.Format(_T("Test data #%d in table %d, row 0!"), m_nCount, (int) m_nTable);
#ifdef UNICODE
	m_pDB->Write(m_nTable, 0, csText);
#else
	WCHAR szuText[80]; // special treatment for ASCII client
	MultiByteToWideChar(CP_ACP, MB_PRECOMPOSED, csText, -1, szuText, sizeof(szuText));
	m_pDB->Write(m_nTable, 0, szuText);
#endif
}

void CDBDoc::OnUpdateReadTable(CCmdUI* pCmdUI) 
{
	pCmdUI->Enable(m_nCount>0);
}

void CDBDoc::OnUpdateWriteTable(CCmdUI* pCmdUI) 
{
	pCmdUI->Enable(m_nTable>=0);
}