大家都知道，使用微软的MFC ActiveX控件向导生成的控件类，是基于COleControl的，而COleControl是基于CWnd类。这样很多MFC的特性，如CFrameWnd的特性，CSingleDocTemplate（SDI）的特性等就无法使用了。如果要把用到这些类的MFC程序封装为ActiveX插件，就会有不少麻烦。
其实这个问题，在上个世纪MFC诞生不久，就有人解决了，并提供了完整的示例代码。微软官方的这篇文章《Designing ActiveX Components with the MFC Document/View Model》，在原地址http://www.microsoft.com/mind/0497/mfc.asp已经无法找到了。
但好在这里还有完整的备份《Designing ActiveX Components with the MFC Document/View Model》。
原文的作者，实现了CActiveXDocTemplate和CActiveXDocControl两个类，而用户只需要将控件的基类从COleControl换为CActiveXDocControl，并做简单修改，就可以方便的使用SDI的特性了。
整体思路其实是使用CActiveXDocControl扩展了COleControl。在CActiveXDocControl中，作者初始化了CDocManager，使用CActiveXDocTemplate控制了document、view、frame的生成，处理了OnSize事件，并使用Timer定时获取消息处理更新。
我们使用的时候，主要就是用这两个类，代码如下（两个类相互引用，所以放到了同一文件中）：
1、ActivDoc.h
class CActiveXDocTemplate : public CSingleDocTemplate
{
enum { IDR_NOTUSED = 0x7FFF };
CWnd* m_pParentWnd;
CFrameWnd* m_pFrameWnd;
CString m_docFile;
public:
CActiveXDocTemplate(CRuntimeClass* pDocClass,
CRuntimeClass* pFrameClass, CRuntimeClass* pViewClass);
CFrameWnd* CreateDocViewFrame(CWnd* pParentWnd);
void SaveDocumentFile();
virtual CFrameWnd* CreateNewFrame(CDocument* pDoc,
CFrameWnd* pOther);
virtual CDocument* OpenDocumentFile(
LPCTSTR lpszPathName, BOOL bVerifyExists = TRUE);
};
//===================================================
class CActiveXDocControl : public COleControl
{
enum { WM_IDLEUPDATECMDUI = 0x0363 };
static BOOL m_bDocInitialized;
CActiveXDocTemplate* m_pDocTemplate;
CFrameWnd* m_pFrameWnd;
DECLARE_DYNAMIC(CActiveXDocControl)
protected:
void AddDocTemplate(CActiveXDocTemplate* pDocTemplate);
CDocTemplate* GetDocTemplate() { return m_pDocTemplate; }
//{{AFX_MSG(CActiveXDocControl)
afx_msg int OnCreate(LPCREATESTRUCT lpCreateStruct);
afx_msg void OnSize(UINT nType, int cx, int cy);
afx_msg void OnTimer(UINT nIDEvent);
afx_msg void OnDestroy();
//}}AFX_MSG
//{{AFX_DISPATCH(CActiveXDocControl)
//}}AFX_DISPATCH
//{{AFX_EVENT(CActiveXDocControl)
//}}AFX_EVENT
DECLARE_MESSAGE_MAP()
DECLARE_DISPATCH_MAP()
DECLARE_EVENT_MAP()
public:
CActiveXDocControl();
virtual ~CActiveXDocControl();
enum {
//{{AFX_DISP_ID(CActiveXDocControl)
//}}AFX_DISP_ID
};
};
2、ActivDoc.cpp
// ActivDoc.cpp : implementation file
//
#include "stdafx.h"
#include "ActivDoc.h"
CActiveXDocTemplate::CActiveXDocTemplate(CRuntimeClass* pDocClass,
CRuntimeClass* pFrameClass, CRuntimeClass* pViewClass)
: CSingleDocTemplate(IDR_NOTUSED, pDocClass, pFrameClass,
pViewClass)
{
ASSERT(pFrameClass);
}
CFrameWnd* CActiveXDocTemplate::CreateDocViewFrame(CWnd* pParentWnd)
{
ASSERT(pParentWnd && IsWindow(*pParentWnd));
ASSERT_KINDOF(CActiveXDocControl, pParentWnd);
m_pParentWnd = pParentWnd;
m_pFrameWnd = NULL;
// OpenDocumentFile is a virtual method (implemented in
// the CSingleDocTemplate base class) that creates
// the document (either empty or loaded from the specified
// file) and calls our CreateNewFrame function. Passing
// NULL to the function creates a new document. Incidentally,
// the view is created by the CFrameWnd's OnCreateClient()
// method.
if (!OpenDocumentFile(NULL))
return NULL;
// Since OpenDocumentFile sets m_pFrame, we can now use it.
ASSERT(m_pFrameWnd);
ASSERT_KINDOF(CFrameWnd, m_pFrameWnd);
m_pFrameWnd->ShowWindow(SW_SHOWNORMAL);
return m_pFrameWnd;
}
CFrameWnd* CActiveXDocTemplate::CreateNewFrame(CDocument* pDoc,
CFrameWnd* pOther)
{
ASSERT(pOther == NULL);
ASSERT(m_pFrameClass != NULL);
if (pDoc != NULL)
ASSERT_VALID(pDoc);
// Create a frame wired to the specified document
CCreateContext context;
context.m_pCurrentFrame = pOther;
context.m_pCurrentDoc = pDoc;
context.m_pNewViewClass = m_pViewClass;
context.m_pNewDocTemplate = this;
m_pFrameWnd = (CFrameWnd*)m_pFrameClass->CreateObject();
if (m_pFrameWnd == NULL)
{
TRACE1("Warning: Dynamic create of frame %hs failed.\n",
m_pFrameClass->m_lpszClassName);
return NULL;
}
ASSERT_KINDOF(CFrameWnd, m_pFrameWnd);
if (context.m_pNewViewClass == NULL)
TRACE0("Warning: creating frame with no default view.\n");
// The frame is created as a menu-less child of the
// CActiveXDocControl in which it will reside.
ASSERT_KINDOF(CActiveXDocControl, m_pParentWnd);
if (!m_pFrameWnd->Create(NULL, "", WS_CHILD|WS_VISIBLE,
CFrameWnd::rectDefault, m_pParentWnd, NULL, 0, &context))
{
TRACE0("Warning: CDocTemplate couldn't create a frame.\n");
return NULL;
}
return m_pFrameWnd;
}
CDocument* CActiveXDocTemplate::OpenDocumentFile(
LPCTSTR lpszPathName, BOOL bVerifyExists)
{
SaveDocumentFile();
m_docFile = lpszPathName;
if (bVerifyExists)
{
DWORD dwAttrib = GetFileAttributes(m_docFile);
if (dwAttrib == 0xFFFFFFFF ||
dwAttrib == FILE_ATTRIBUTE_DIRECTORY)
{
lpszPathName = NULL;
}
}
return CSingleDocTemplate::OpenDocumentFile(
lpszPathName, TRUE);
}
void CActiveXDocTemplate::SaveDocumentFile()
{
if (m_pOnlyDoc != NULL)
{
if (!m_docFile.IsEmpty())
m_pOnlyDoc->OnSaveDocument(m_docFile);
else
m_pOnlyDoc->SetModifiedFlag(FALSE);
}
}
//===================================================
// CActiveXDocControl
IMPLEMENT_DYNAMIC(CActiveXDocControl, COleControl)
BEGIN_MESSAGE_MAP(CActiveXDocControl, COleControl)
//{{AFX_MSG_MAP(CActiveXDocControl)
ON_WM_CREATE()
ON_WM_SIZE()
ON_WM_TIMER()
ON_WM_DESTROY()
//}}AFX_MSG_MAP
ON_OLEVERB(AFX_IDS_VERB_PROPERTIES, OnProperties)
END_MESSAGE_MAP()
BEGIN_DISPATCH_MAP(CActiveXDocControl, COleControl)
//{{AFX_DISPATCH_MAP(CActiveXDocControl)
//}}AFX_DISPATCH_MAP
END_DISPATCH_MAP()
BEGIN_EVENT_MAP(CActiveXDocControl, COleControl)
//{{AFX_EVENT_MAP(COleFrameCtrl)
//}}AFX_EVENT_MAP
END_EVENT_MAP()
int CActiveXDocControl::m_bDocInitialized = FALSE;
CActiveXDocControl::CActiveXDocControl()
{
m_pDocTemplate = NULL;
m_pFrameWnd = NULL;
// Since we're in an OCX, CWinApp::InitApplication() is
// not called by the framework. Unfortunately, that method
// performs CDocManager initialization that is necessary
// in order for our DocTemplate to clean up after itself.
// We simulate the same initialization by calling the
// following code the first time we create a control.
if (!m_bDocInitialized)
{
CDocManager docManager;
docManager.AddDocTemplate(NULL);
m_bDocInitialized = TRUE;
}
}
CActiveXDocControl::~CActiveXDocControl()
{
// Note that the frame, the document, and the view are
// all deleted automatically by the framework!
delete m_pDocTemplate;
}
void CActiveXDocControl::AddDocTemplate(CActiveXDocTemplate* pDocTemplate)
{
// I've decided to call this function AddDocTemplate to
// be consistent with naming of CWinApp::AddDocTemplate.
// However, only one DocTemplate is allowed per control.
ASSERT(pDocTemplate);
ASSERT(m_pDocTemplate == NULL);
m_pDocTemplate = pDocTemplate;
}
int CActiveXDocControl::OnCreate(LPCREATESTRUCT lpCreateStruct)
{
if (COleControl::OnCreate(lpCreateStruct) == -1)
return -1;
// The CActiveXDocTemplate object will create the
// document, the view, and the frame inside the
// control. The reason we need a handle to the frame
// is so that we can resize it when the control is
// resized.
ASSERT(m_pDocTemplate); // Set in call to AddDocTemplate
m_pFrameWnd = m_pDocTemplate->CreateDocViewFrame(this);
ASSERT_KINDOF(CFrameWnd, m_pFrameWnd);
// By default, we'll create the control with a border,
// since it looks better for frames containing a toolbar.
SetBorderStyle(TRUE);
SetTimer(WM_IDLEUPDATECMDUI, 300, NULL);
return 0;
}
void CActiveXDocControl::OnSize(UINT nType, int cx, int cy)
{
COleControl::OnSize(nType, cx, cy);
// The CFrameWnd should always fill up the entire client
// area of the control.
if (m_pFrameWnd != NULL)
{
ASSERT(IsWindow(*m_pFrameWnd));
CRect area;
GetClientRect(area);
m_pFrameWnd->MoveWindow(area.left, area.top, area.right,
area.bottom);
}
}
void CActiveXDocControl::OnTimer(UINT nIDEvent)
{
// Since we're in an OCX, we don't control the message loop,
// so CWinThread::OnIdle is never called. That means we have
// to periodically pump the ON_UPDATE_COMMAND_UI messages
// by hand.
SendMessageToDescendants(WM_IDLEUPDATECMDUI, TRUE);
COleControl::OnTimer(nIDEvent);
}
void CActiveXDocControl::OnDestroy()
{
AfxGetApp()->m_pMainWnd = NULL;
m_pDocTemplate->SaveDocumentFile();
COleControl::OnDestroy();
}
困了，回去再写。。。