mfc浅析(1) 文档视图结构中，缺省的命令处理

文档视图结构中，缺省的命令处理

FMD(http://www.fmdstudio.net)

文档视图结构中，缺省的命令处理

在文档视图结构所构建的框架中，很多命令ID都有缺省的命令处理。

正在装载数据……

很多功能都由他们完成，但这些功能在程序中不“ 可见” ,不便于对程序的理解。

以下归纳了常见的缺省处理及其流程

在需要时候，可以重载这些函数以实现特定功能

1.ID_FILE_NEW

2.ID_FILE_OPEN

3.ID_FILE_SAVE

4.ID_FILE_SAVE_AS

5.ID_FILE_SAVE_COPY_AS

6.ID_FILE_CLOSE

7.ID_FILE_UPDATE

8.ID_FILE_PRINT_SETUP

9.ID_FILE_PRINT

10.ID_FILE_PRINT_divVIEW

11.缺省编辑控制ID

12.ID_WINDOW_NEW

13.ID_WINDOW_ARRANGE

14.ID_WINDOW_CASCADE

15.ID_WINDOW_TILE_HORZ

16.ID_WINDOW_TILE_VERT

17.ID_WINDOW_SPLIT

18.ID_APP_ABOUT

19.ID_APP_EXIT

20.ID_HELP_INDEX

21.ID_HELP_USING

22.ID_CONTEXT_HELP

23.ID_HELP

24.ID_DEFAULT_HELP

25.ID_NEXT_PANE

26.ID_divV_PANE

27.ID_OLE_INSERT_NEW

28.ID_OLE_EDIT_LINKS

29.ID_VIEW_TOOLBAR

30.ID_VIEW_STATUS_BAR

1.ID_FILE_NEW

CWinApp::OnFileNew

调用m_pDocManager->OnFileNew()

void CDocManager::OnFileNew(){ if (m_templateList.IsEmpty()) { TRACE0("Error: no document templates registered with CWinApp./n"); AfxMessageBox(AFX_IDP_FAILED_TO_CREATE_DOC); return ; } CDocTemplate* pTemplate = (CDocTemplate*)m_templateList.GetHead(); //如果含有多个文档模板，显示一个新建文档类型对话框 if (m_templateList.GetCount() > 1) { // more than one document template to choose from // bring up dialog prompting user CNewTypeDlg dlg(&m_templateList); int nID = dlg.DoModal(); if (nID == IDOK) pTemplate = dlg.m_pSelectedTemplate; else return ; // none - cancel operation } ASSERT(pTemplate != NULL); ASSERT_KINDOF(CDocTemplate, pTemplate); //建立空文件 pTemplate->OpenDocumentFile(NULL); // if returns NULL, the user has already been alerted }

2.ID_FILE_OPEN

CWinApp::OnFileOpen

调用m_pDocManager->OnFileOpen()

void CDocManager::OnFileOpen(){ //出现打开文件对话框文件取得文件名 CString newName; if (!DoPromptFileName(newName, AFX_IDS_OPENFILE, OFN_HIDEREADONLY ¦ OFN_FILEMUSTEXIST, TRUE, NULL)) return ; //使用OpenDocumentFile AfxGetApp()->OpenDocumentFile(newName); // if returns NULL, the user has already been alerted }

3.ID_FILE_SAVE

CDocument::OnFileSave()

调用DoFileSave()

void CDocument::OnFileSave(){ DoFileSave();}

DoFileSave()又将调用DoSave()

BOOL CDocument::DoFileSave(){ DWORD dwAttrib = GetFileAttributes(m_strPathName); //如果文件是只读,或已经不存在了 if (dwAttrib & FILE_ATTRIBUTE_READONLY) { //使用带NULL参数的DoSave if (!DoSave(NULL)) { TRACE0("Warning: File save with new name failed./n"); return FALSE; } } else { //使用DoSave(....) if (!DoSave(m_strPathName)) { TRACE0("Warning: File save failed./n"); return FALSE; } } return TRUE;}

DoSave()的实现

BOOL CDocument::DoSave(LPCTSTR lpszPathName, BOOL bReplace)//如果文件名参数为空，则让用户取名 // note: lpszPathName can be different than 'm_strPathName' { CString newName = lpszPathName; if (newName.IsEmpty()) { CDocTemplate* pTemplate = GetDocTemplate(); ASSERT(pTemplate != NULL); newName = m_strPathName; if (bReplace && newName.IsEmpty()) { newName = m_strTitle; // check for dubious filename int iBad = newName.FindOneOf(_T(" #%;///")); if (iBad != -1) newName.ReleaseBuffer(iBad); // append the default suffix if there is one CString strExt; if (pTemplate->GetDocString(strExt, CDocTemplate::filterExt) && !strExt.IsEmpty()) { ASSERT(strExt[0] == '.'); newName += strExt; } } //"保存为"对话框 if (!AfxGetApp()->DoPromptFileName(newName, bReplace ? AFX_IDS_SAVEFILE : AFX_IDS_SAVEFILECOPY, OFN_HIDEREADONLY ¦ OFN_PATHMUSTEXIST, FALSE, pTemplate)) return FALSE; // don't even attempt to save } CWaitCursor wait; //保存,由OnSaveDocument完成 if (!OnSaveDocument(newName)) { if (lpszPathName == NULL) { // be sure to delete the file TRY { CFile::Remove(newName); } CATCH_ALL(e) { TRACE0("Warning: failed to delete file /n"); DELETE_EXCEPTION(e); } END_CATCH_ALL } return FALSE; } // reset the title and change the document name if (bReplace) SetPathName(newName); return TRUE; // success }

使用了文档类的OnSaveDocument完成保存动作

BOOL CDocument::OnSaveDocument(LPCTSTR lpszPathName){ CFileException fe; CFile* pFile = NULL; pFile = GetFile(lpszPathName, CFile::modeCreate ¦ CFile::modeReadWrite ¦ CFile::shareExclusive, &fe); if (pFile == NULL) { ReportSaveLoadException(lpszPathName, &fe, TRUE, AFX_IDP_INVALID_FILENAME); return FALSE; } //建立保存用的CArchive CArchive saveArchive(pFile, CArchive::store ¦ CArchive::bNoFlushOnDelete); saveArchive.m_pDocument = this ; saveArchive.m_bForceFlat = FALSE; TRY { CWaitCursor wait; //使用文档类的序列化操作完成实际存档行为 Serialize(saveArchive); // save me saveArchive.Close(); ReleaseFile(pFile, FALSE); } CATCH_ALL(e) { ReleaseFile(pFile, TRUE); TRY { ReportSaveLoadException(lpszPathName, e, TRUE, AFX_IDP_FAILED_TO_SAVE_DOC); } END_TRY DELETE_EXCEPTION(e); return FALSE; } END_CATCH_ALL SetModifiedFlag(FALSE); // back to unmodified return TRUE; // success }

4.ID_FILE_SAVE_AS

CDocument::OnFileSaveAs()

具体实现：调用NULL参数的DoSave(..)

void CDocument::OnFileSaveAs(){ if (!DoSave(NULL)) TRACE0("Warning: File save-as failed./n");}

5.ID_FILE_SAVE_COPY_AS

The COleServerDoc::OnFileSaveCopyAs

6.ID_FILE_CLOSE

CDocument::OnFileClose

void CDocument::OnFileClose(){ //保存内容 if (!SaveModified()) return ; //关闭文档 OnCloseDocument();}

如果需要保存，调用DoFileSave(..)

BOOL CDocument::SaveModified(){ //没有改动 if (!IsModified()) return TRUE; //得到文件名 CString name; if (m_strPathName.IsEmpty()) { // get name based on caption name = m_strTitle; if (name.IsEmpty()) VERIFY(name.LoadString(AFX_IDS_UNTITLED)); } else { // get name based on file title of path name name = m_strPathName; if (afxData.bMarked4) { AfxGetFileTitle(m_strPathName, name.GetBuffer(_MAX_PATH), _MAX_PATH); name.ReleaseBuffer(); } } CString prompt; AfxFormatString1(prompt, AFX_IDP_ASK_TO_SAVE, name); //对话框:文件已被改动，是否保存 switch (AfxMessageBox(prompt, MB_YESNOCANCEL, AFX_IDP_ASK_TO_SAVE)) { case IDCANCEL: return FALSE; // don't continue case IDYES: //保存文件 if (!DoFileSave()) return FALSE; // don't continue break ; case IDNO: // If not saving changes, revert the document break ; default : ASSERT(FALSE); break ; } return TRUE;}

7.ID_FILE_UPDATE

COleServerDoc::OnUpdateDocument

8.ID_FILE_PRINT_SETUP

CWinApp::OnFilePrintSetup

9.ID_FILE_PRINT

CView::OnFilePrint

10.ID_FILE_PRINT_divVIEW

CView::OnFilePrintPreview

11.缺省编辑控制ID

ID_EDIT_CLEAR

ID_EDIT_CLEAR_ALL

ID_EDIT_COPY

ID_EDIT_CUT

ID_EDIT_FIND

ID_EDIT_PASTE

ID_EDIT_PASTE_LINK

ID_EDIT_PASTE_SPECIAL

ID_EDIT_REPEAT

ID_EDIT_REPLACE

ID_EDIT_SELECT_ALL

ID_EDIT_UNDO

ID_EDIT_REDO

这些ID在对应的编辑视中有相应处理函数

12.ID_WINDOW_NEW

CMDIFrameWnd::OnWindowNew

void CMDIFrameWnd::OnWindowNew(){ //找到当前窗口，得到对应文档模板，使用文档模板的成员CreateNewFrame建立新窗口 CMDIChildWnd* pActiveChild = MDIGetActive(); CDocument* pDocument; if (pActiveChild == NULL ¦¦ (pDocument = pActiveChild->GetActiveDocument()) == NULL) { TRACE0("Warning: No active document for WindowNew command./n"); AfxMessageBox(AFX_IDP_COMMAND_FAILURE); return ; // command failed } // otherwise we have a new frame ! CDocTemplate* pTemplate = pDocument->GetDocTemplate(); ASSERT_VALID(pTemplate); CFrameWnd* pFrame = pTemplate->CreateNewFrame(pDocument, pActiveChild); if (pFrame == NULL) { TRACE0("Warning: failed to create new frame./n"); return ; // command failed } pTemplate->InitialUpdateFrame(pFrame, pDocument);}

13.ID_WINDOW_ARRANGE

ID_WINDOW_ARRANGE,以及ID_WINDOW_CASCADE、ID_WINDOW_TILE_HORZ、ID_WINDOW_TILE_VERT都由OnMDIWindowCmd()处理

OnMDIWindowCmd将相应消息发送给m_hWndMDIClient

BOOL CMDIFrameWnd::OnMDIWindowCmd(UINT nID){ ASSERT(m_hWndMDIClient != NULL); UINT msg; UINT wParam = 0; switch (nID) { default : return FALSE; // not for us case ID_WINDOW_ARRANGE: msg = WM_MDIICONARRANGE; break ; case ID_WINDOW_CASCADE: msg = WM_MDICASCADE; break ; case ID_WINDOW_TILE_HORZ: wParam = MDITILE_HORIZONTAL; // fall through case ID_WINDOW_TILE_VERT: ASSERT(MDITILE_VERTICAL == 0); msg = WM_MDITILE; break ; } ::SendMessage(m_hWndMDIClient, msg, wParam, 0); return TRUE;}

14.ID_WINDOW_CASCADE

参见ID_WINDOW_ARRANGE

15.ID_WINDOW_TILE_HORZ

参见ID_WINDOW_ARRANGE

16.ID_WINDOW_TILE_VERT

参见ID_WINDOW_ARRANGE

17.ID_WINDOW_SPLIT

CSplitterWnd::DoKeyboardSplit

用键盘控制分割窗口

BOOL CSplitterWnd::DoKeyboardSplit(){ ASSERT_VALID(this ); int ht; if (m_nRows > 1 && m_nCols > 1) ht = splitterIntersection1; // split existing row+col else if (m_nRows > 1) ht = vSplitterBar1; // split existing row else if (m_nCols > 1) ht = hSplitterBar1; // split existing col else if (m_nMaxRows > 1 && m_nMaxCols > 1) ht = bothSplitterBox; // we can split both else if (m_nMaxRows > 1) ht = vSplitterBox; // we can split rows else if (m_nMaxCols > 1) ht = hSplitterBox; // we can split columns else return FALSE; // can't split // start tracking StartTracking(ht); CRect rect; rect.left = m_rectTracker.Width() / 2; rect.top = m_rectTracker.Height() / 2; if (m_ptTrackOffset.y != 0) rect.top = m_rectTracker.top; if (m_ptTrackOffset.x != 0) rect.left = m_bTracking2 ? m_rectTracker2.left :m_rectTracker.left; rect.OffsetRect(-m_ptTrackOffset.x, -m_ptTrackOffset.y); ClientToScreen(&rect); SetCursorPos(rect.left, rect.top); return TRUE;}

18.ID_APP_ABOUT

建立CWinApp::OnAppAbout();

19.ID_APP_EXIT

CWinApp::OnAppExit

直接向主窗口发送WM_CLOSE消息

void CWinApp::OnAppExit(){ // same as double-clicking on main window close box ASSERT(m_pMainWnd != NULL); m_pMainWnd->SendMessage(WM_CLOSE);}

20.ID_HELP_INDEX

CWinApp::OnHelpIndex

21.ID_HELP_USING

CWinApp::OnHelpUsing

22.ID_CONTEXT_HELP

CWinApp::OnContextHelp

23.ID_HELP

CWinApp::OnHelp

24.ID_DEFAULT_HELP

CWinApp::OnHelpIndex

25.ID_NEXT_PANE

CSplitterWnd::OnNextPaneCmd

26.ID_divV_PANE

CSplitterWnd::OnNextPaneCmd

27.ID_OLE_INSERT_NEW

28.ID_OLE_EDIT_LINKS

29.ID_VIEW_TOOLBAR

切换AFX_IDW_TOOLBAR工具条

消息映射

ON_UPDATE_COMMAND_UI(ID_VIEW_TOOLBAR, OnUpdateControlBarMenu)

ON_COMMAND_EX(ID_VIEW_TOOLBAR, OnBarCheck)

BOOL CFrameWnd::OnBarCheck(UINT nID){ ASSERT(ID_VIEW_STATUS_BAR == AFX_IDW_STATUS_BAR); ASSERT(ID_VIEW_TOOLBAR == AFX_IDW_TOOLBAR); ASSERT(ID_VIEW_REBAR == AFX_IDW_REBAR); CControlBar* pBar = GetControlBar(nID); if (pBar != NULL) { //设置该工具条状态 ShowControlBar(pBar, (pBar->GetStyle() & WS_VISIBLE) == 0, FALSE); return TRUE; } return FALSE;}

void CFrameWnd::OnUpdateControlBarMenu(CCmdUI* pCmdUI){ ASSERT(ID_VIEW_STATUS_BAR == AFX_IDW_STATUS_BAR); ASSERT(ID_VIEW_TOOLBAR == AFX_IDW_TOOLBAR); ASSERT(ID_VIEW_REBAR == AFX_IDW_REBAR); CControlBar* pBar = GetControlBar(pCmdUI->m_nID); if (pBar != NULL) { pCmdUI->SetCheck((pBar->GetStyle() & WS_VISIBLE) != 0); return ; } pCmdUI->ContinueRouting();}

30.ID_VIEW_STATUS_BAR

实现方法与ID_VIEW_TOOLBAR相同