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。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_S***E
4.ID_FILE_S***E_AS
5.ID_FILE_S***E_COPY_AS

6.ID_FILE_CLOSE
7.ID_FILE_UPDATE
8.ID_FILE_PRINT_SETUP
9.ID_FILE_PRINT
10.ID_FILE_PRINT_PREVIEW
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_PREV_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_S***E
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_S***EFILE : AFX_IDS_S***EFILECOPY,
    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_S***E_DOC);
  }
  END_TRY
  DELETE_EXCEPTION(e);
  return FALSE;
 }
 END_CATCH_ALL
 SetModifiedFlag(FALSE);     // back to unmodified
 return TRUE;        // success
}

4.ID_FILE_S***E_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_S***E_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_S***E, name);
 //对话框:文件已被改动，是否保存
 switch (AfxMessageBox(prompt, MB_YESNOCANCEL, AFX_IDP_ASK_TO_S***E))
 {
 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_PREVIEW
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_PREV_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

转帖：http://blog.csdn.net/FMD/article/details/5522