首页 > 代码库 > MFC File相关命令流程分析
MFC File相关命令流程分析
一个APP可以有多个文档模板，一个文档模板可以有多个文档（Document），一个Document可以有多个View。在程序。要在程序中添加新的文档模板可以如下所示：
CSingleDocTemplate*pDocTemplate;
pDocTemplate = newCSingleDocTemplate(
IDR_MAINFRAME,
RUNTIME_CLASS(CmfcArchiveDoc),
RUNTIME_CLASS(CMainFrame), // 主 SDI 框架窗口
RUNTIME_CLASS(CmfcArchiveView));
if(!pDocTemplate)
returnFALSE;
AddDocTemplate(pDocTemplate);
CSingleDocTemplate* pDocNew;
pDocNew = newCSingleDocTemplate(
IDR_MAINFRAME,
RUNTIME_CLASS(CmfcArchiveDoc),
RUNTIME_CLASS(CMainFrame), // 主 SDI 框架窗口
RUNTIME_CLASS(CmfcArchiveView));
if (pDocNew == NULL)
returnFALSE;
AddDocTemplate(pDocNew);1 程序启动
在程序初始化或者点击菜单新建的时候都会调用OnNewDocument函数。具体流程如下所示：
<1>CWinApp::OnFileNew()//appdlg.cpp
void CWinApp::OnFileNew()
{
if(m_pDocManager != NULL)
m_pDocManager->OnFileNew();
}<2>CDocManager::OnFileNew() //docmgr.cpp
void CDocManager::OnFileNew()
{
if(m_templateList.IsEmpty())
{
TRACE(traceAppMsg, 0, "Error: no document templates registered withCWinApp.\n");
AfxMessageBox(AFX_IDP_FAILED_TO_CREATE_DOC);
return;
}
CDocTemplate* pTemplate =(CDocTemplate*)m_templateList.GetHead();
if(m_templateList.GetCount() > 1)
{
//more than one document template to choose from
//bring up dialog prompting user
CNewTypeDlgdlg(&m_templateList);
INT_PTR nID = dlg.DoModal();
if(nID == IDOK)
pTemplate =dlg.m_pSelectedTemplate;
else
return; // none - cancel operation
}
ASSERT(pTemplate != NULL);
ASSERT_KINDOF(CDocTemplate, pTemplate);
pTemplate->OpenDocumentFile(NULL);
//if returns NULL, the user has already been alerted
}从这个函数可以看到首次运行程序的时候吧，程序会从成员变量m_templateList这里获取程序的模板中的列表，并且弹出对话框供user选择使用哪一个模板
最后在pTemplate->OpenDocumentFile(NULL)调用OpenDocumentFlle函数，因为这个文档模板是单文档的 ，所以pTemplate是CSingleTemplate类型的。
<3> CSingleDocTemplate::OpenDocumentFile(LPCTSTRlpszPathName, BOOL bMakeVisible)
CDocument*CSingleDocTemplate::OpenDocumentFile(LPCTSTR lpszPathName, BOOL bMakeVisible)
{
returnOpenDocumentFile(lpszPathName, TRUE, bMakeVisible);
}<4> CSingleDocTemplate::OpenDocumentFile(LPCTSTRlpszPathName, BOOL bAddToMRU, BOOL bMakeVisible)
这个函数时主要的函数
CDocument*CSingleDocTemplate::OpenDocumentFile(LPCTSTR lpszPathName, BOOL bAddToMRU, BOOLbMakeVisible)
{
CDocument* pDocument = NULL;
CFrameWnd* pFrame = NULL;
BOOL bCreated = FALSE; // => docand frame created
BOOL bWasModified = FALSE;
if(m_pOnlyDoc != NULL)
{
//already have a document - reinit it
pDocument = m_pOnlyDoc;
if(!pDocument->SaveModified())
{
// set a flag to indicate that the document being openedshould not
// be removed from the MRU list, if it was being openedfrom there
g_bRemoveFromMRU =FALSE;
return NULL; // leave the original one
}
pFrame =(CFrameWnd*)AfxGetMainWnd();
ASSERT(pFrame != NULL);
ASSERT_KINDOF(CFrameWnd,pFrame);
ASSERT_VALID(pFrame);
}
else
{
//create a new document
pDocument = CreateNewDocument();
ASSERT(pFrame == NULL); // will becreated below
bCreated = TRUE;
}
if(pDocument == NULL)
{
AfxMessageBox(AFX_IDP_FAILED_TO_CREATE_DOC);
returnNULL;
}
ASSERT(pDocument == m_pOnlyDoc);
if(pFrame == NULL)
{
ASSERT(bCreated);
//create frame - set as main document frame
BOOL bAutoDelete =pDocument->m_bAutoDelete;
pDocument->m_bAutoDelete =FALSE;
// don't destroy if something goes wrong
pFrame =CreateNewFrame(pDocument, NULL);
pDocument->m_bAutoDelete =bAutoDelete;
if(pFrame == NULL)
{
AfxMessageBox(AFX_IDP_FAILED_TO_CREATE_DOC);
delete pDocument; // explicitdelete on error
return NULL;
}
}
if(lpszPathName == NULL)
{
//create a new document
SetDefaultTitle(pDocument);
//avoid creating temporary compound file when starting up invisible
if(!bMakeVisible)
pDocument->m_bEmbedded= TRUE;
if (!pDocument->OnNewDocument())
{
// user has been alerted to what failed in OnNewDocument
TRACE(traceAppMsg,0, "CDocument::OnNewDocument returnedFALSE.\n");
if (bCreated)
pFrame->DestroyWindow(); // will destroydocument
return NULL;
}
}
else
{
CWaitCursor wait;
//open an existing document
bWasModified =pDocument->IsModified();
pDocument->SetModifiedFlag(FALSE); // not dirty foropen
if (!pDocument->OnOpenDocument(lpszPathName))
{
// user has been alerted to what failed in OnOpenDocument
TRACE(traceAppMsg,0, "CDocument::OnOpenDocument returnedFALSE.\n");
if (bCreated)
{
pFrame->DestroyWindow(); // will destroydocument
}
else if(!pDocument->IsModified())
{
// original document is untouched
pDocument->SetModifiedFlag(bWasModified);
}
else
{
// we corrupted the original document
SetDefaultTitle(pDocument);
if (!pDocument->OnNewDocument())
{
TRACE(traceAppMsg,0, "Error: OnNewDocument failed after trying"
"to open a document - trying to continue.\n");
// assume we can continue
}
}
return NULL; // open failed
}
pDocument->SetPathName(lpszPathName,bAddToMRU);
pDocument->OnDocumentEvent(CDocument::onAfterOpenDocument);
}
CWinThread* pThread = AfxGetThread();
ASSERT(pThread);
if(bCreated && pThread->m_pMainWnd == NULL)
{
//set as main frame (InitialUpdateFrame will show the window)
pThread->m_pMainWnd =pFrame;
}
InitialUpdateFrame(pFrame, pDocument,bMakeVisible);
returnpDocument;
}因为是第一次打开程序，所以会新建一个CDocument，以及MainFrame，最后就会调用我们自己写的OnNewDocument。<5> CmfcArchiveDoc::OnNewDocument()
BOOLCmfcArchiveDoc::OnNewDocument()
{
if(!CDocument::OnNewDocument())
returnFALSE;
// TODO: 在此添加重新初始化代码
// (SDI 文档将重用该文档)
returnTRUE;
}在这个函数里面会调用CDocument::OnNewDocument
总结：
<1>CWinApp::OnFileNew()//appdlg.cpp
<2>CDocManager::OnFileNew() //docmgr.cpp
<3>CSingleDocTemplate::OpenDocumentFile(LPCTSTRlpszPathName, BOOL bMakeVisible)
<4>CSingleDocTemplate::OpenDocumentFile(LPCTSTRlpszPathName, BOOL bAddToMRU, BOOL bMakeVisible)
<5>CmfcArchiveDoc::OnNewDocument()
2 文件新建
文件新建的流程跟程序初次打开流程一样，只不过在CSingleDocTemplate::OpenDocumentFile(LPCTSTRlpszPathName, BOOL bAddToMRU, BOOL bMakeVisible)
中函数执行的内容可能不同，如果打开的是同一个文档模板的话，那么就不会再去创建文档，FrameWindow。否则的话就要新建新的模板。
3 文件打开
文件打开以及文件关闭会执行的命令是ID_FILE_OPEN，ID_FILE_SAVE。这两个命令都是跟文档串行化有关的，一个是存档，一个载入。
<1> CWinApp::OnFileOpen()
void CWinApp::OnFileOpen()
{
ENSURE(m_pDocManager != NULL);
m_pDocManager->OnFileOpen();
}<2> CDocManager::OnFileOpen()void CDocManager::OnFileOpen()
{
// prompt theuser (with all document templates)
CString newName;
if(!DoPromptFileName(newName, AFX_IDS_OPENFILE,
OFN_HIDEREADONLY | OFN_FILEMUSTEXIST, TRUE, NULL))
return;// open cancelled
AfxGetApp()->OpenDocumentFile(newName);
//if returns NULL, the user has already been alerted
} 其中DoPromptFileName函数会弹出一个对话框提示选择要打开的文件，并且在选定后会保存文件的名字和路径。<3> CWinApp::OpenDocumentFile(LPCTSTR lpszFileName)
CDocument*CWinApp::OpenDocumentFile(LPCTSTR lpszFileName)
{
ENSURE_VALID(m_pDocManager);
returnm_pDocManager->OpenDocumentFile(lpszFileName);
}<4> CDocManager::OpenDocumentFile(LPCTSTRlpszFileName)
CDocument*CDocManager::OpenDocumentFile(LPCTSTR lpszFileName)
{
returnOpenDocumentFile(lpszFileName, TRUE);
}<5>CDocManager::OpenDocumentFile(LPCTSTR lpszFileName, BOOL bAddToMRU)
CDocument*CDocManager::OpenDocumentFile(LPCTSTR lpszFileName, BOOL bAddToMRU)
{
if(lpszFileName == NULL)
{
AfxThrowInvalidArgException();
}
// find thehighest confidence
POSITION pos =m_templateList.GetHeadPosition();
CDocTemplate::Confidence bestMatch =CDocTemplate::noAttempt;
CDocTemplate* pBestTemplate = NULL;
CDocument* pOpenDocument = NULL;
TCHAR szPath[_MAX_PATH];
ASSERT(lstrlen(lpszFileName) <_countof(szPath));
TCHAR szTemp[_MAX_PATH];
if(lpszFileName[0] == '\"')
++lpszFileName;
Checked::tcsncpy_s(szTemp,_countof(szTemp), lpszFileName, _TRUNCATE);
LPTSTR lpszLast = _tcsrchr(szTemp, '\"');
if(lpszLast != NULL)
*lpszLast = 0;
if(AfxFullPath(szPath, szTemp) == FALSE )
{
ASSERT(FALSE);
returnNULL; // We won't open the file. MFC requires pathswith
//length < _MAX_PATH
}
TCHAR szLinkName[_MAX_PATH];
if(AfxResolveShortcut(AfxGetMainWnd(), szPath, szLinkName, _MAX_PATH))
Checked::tcscpy_s(szPath,_countof(szPath), szLinkName);
while(pos != NULL)
{
CDocTemplate* pTemplate =(CDocTemplate*)m_templateList.GetNext(pos);
ASSERT_KINDOF(CDocTemplate,pTemplate);
CDocTemplate::Confidencematch;
ASSERT(pOpenDocument ==NULL);
match =pTemplate->MatchDocType(szPath, pOpenDocument);
if(match > bestMatch)
{
bestMatch = match;
pBestTemplate =pTemplate;
}
if(match == CDocTemplate::yesAlreadyOpen)
break; // stop here
}
if (pOpenDocument != NULL)
{
POSITION posOpenDoc =pOpenDocument->GetFirstViewPosition();
if(posOpenDoc != NULL)
{
CView* pView =pOpenDocument->GetNextView(posOpenDoc); // getfirst one
ASSERT_VALID(pView);
CFrameWnd* pFrame =pView->GetParentFrame();
if (pFrame == NULL)
TRACE(traceAppMsg,0, "Error: Can not find a frame for documentto activate.\n");
else
{
pFrame->ActivateFrame();
if (pFrame->GetParent() != NULL)
{
CFrameWnd*pAppFrame;
if (pFrame != (pAppFrame =(CFrameWnd*)AfxGetApp()->m_pMainWnd))
{
ASSERT_KINDOF(CFrameWnd,pAppFrame);
pAppFrame->ActivateFrame();
}
}
}
}
else
TRACE(traceAppMsg,0, "Error: Can not find a view for document toactivate.\n");
returnpOpenDocument;
}
if(pBestTemplate == NULL)
{
AfxMessageBox(AFX_IDP_FAILED_TO_OPEN_DOC);
returnNULL;
}
return pBestTemplate->OpenDocumentFile(szPath,bAddToMRU, TRUE);
}程序会判断pDocument是否是NULL，是的话就会调用pBestTemplate->OpenDocumentFile(szPath,bAddToMRU, TRUE);
第一次打开一个文件的时候，必然会调用这个函数的。
<6> CSingleDocTemplate::OpenDocumentFile(LPCTSTRlpszPathName, BOOL bAddToMRU, BOOL bMakeVisible)
这个函数和程序启动以及新建操作的函数一样，关键是调用的部分不用。它调用的部分是：
lpszPathName！= NULL 的部分
else
{
CWaitCursor wait;
//open an existing document
bWasModified =pDocument->IsModified();
pDocument->SetModifiedFlag(FALSE); // not dirty foropen
if (!pDocument->OnOpenDocument(lpszPathName))
{
// user has been alerted to what failed in OnOpenDocument
TRACE(traceAppMsg,0, "CDocument::OnOpenDocument returnedFALSE.\n");
if (bCreated)
{
pFrame->DestroyWindow(); // will destroydocument
}
else if(!pDocument->IsModified())
{
// original document is untouched
pDocument->SetModifiedFlag(bWasModified);
}
else
{
// we corrupted the original document
SetDefaultTitle(pDocument);
if (!pDocument->OnNewDocument())
{
TRACE(traceAppMsg,0, "Error: OnNewDocument failed after trying"
"to open a document - trying to continue.\n");
// assume we can continue
}
}
return NULL; // open failed
}<7> CDocument::OnOpenDocument(LPCTSTR lpszPathName)
Serialize(loadArchive); // load me
OnOpenDocument函数中会调用Serialize()函数。这个Serialize函数是个虚函数，从而会调用的是CmfcArchiveDoc::Serialize(CArchive& ar)
总结：
<1> CWinApp::OnFileOpen()
<2> CDocManager::OnFileOpen()
<3> CWinApp::OpenDocumentFile(LPCTSTR lpszFileName)
<4> CDocManager::OpenDocumentFile(LPCTSTRlpszFileName)
<5>CDocManager::OpenDocumentFile(LPCTSTR lpszFileName, BOOL bAddToMRU)
<6> CSingleDocTemplate::OpenDocumentFile(LPCTSTRlpszPathName, BOOL bAddToMRU, BOOL bMakeVisible)
<7> CDocument::OnOpenDocument(LPCTSTR lpszPathName)
其中要是注意的是如果已经打开了一个文档并且没有关闭，那么在再次打开的时候不会调用序列化函数，原因是当已经打开了一个文档，再次打开它的时候，CDocManager::OnFileOpen()这个函数中的pDocument已经有值了，所以不会再去打开了。
4 文件保存
<1> void CDocument::OnFileSave() //doccore.cpp
<2> BOOL CDocument::DoFileSave() //doccore.cpp
<3> BOOL CDocument::DoSave(LPCTSTR lpszPathName,BOOL bReplace) //doccore.cpp
<4> BOOL CDocument::OnSaveDocument(LPCTSTRlpszPathName) //doccore.cpp
<5> void CmfcArchiveDoc::Serialize(CArchive& ar)
这个就是文件的保存流程。