Switchig views in SDI application.

Switching More than one CView.
In our current project DocuMight there are  multiple file types and corresponding CView derived class . Application type is SDI and we don’t want to edit files. I tried 3 methods for this. 1)      Using Document template Created new CSingleDocTemplate and added using CWinApp:: AddDocTemplate() method. 2)      Dynamically creation of new View via code. Here I found some problem in window creation and deletion. So dynamically creation method doped . 3)      Switching already created views. - I got this method from MSDN sample.
for example Let assume that we have 3 Views CImageView, CDocumentView and CDatabaseView all are derived from CView and our default view is CImageView.Following are the sample code :
#define TOTAL_NUM_VIEWS 3 enum ViewType {       ImageView = 0,      DocumentView = 1,       DataBaseView = 2, };	class CMainFrame : public CFrameWnd {  public:     void InitViews();  private:   // Array of views attached to single document   CView * m_pViews[TOTAL_NUM_VIEWS];   void SwitchView( ViewType viewType);   static void SwapWindowID(const HWND& hWndFirst, const HWND& hWndSecond);   UINT m_nCurView ; };
void CMainFrame::InitViews () {     m_nCurView = 0;        // Save index of the currently active view class     CView* pActiveView = GetActiveView();     m_pViews[ImageView] = pActiveView;     // no need to delete View .     //The application automatically deletes the view when the application is closed.     m_pViews[DocumentView] = (CView*) new CDocumentView;     m_pViews[DataBaseView] = (CView*) new CDatabaseView;     CDocument* pCurrentDoc = GetActiveDocument();        // Initialize a CCreateContext to point to the active document.     // With this context, the new view is added to the document     // when the view is created in CView::OnCreate().     CCreateContext newContext ;     newContext.m_pNewViewClass = NULL;     newContext.m_pNewDocTemplate = NULL;     newContext.m_pLastView = NULL;     newContext.m_pCurrentFrame = NULL;     newContext.m_pCurrentDoc = pCurrentDoc;     for (int nView = 1; nView < TOTAL_NUM_VIEWS; nView++)     {         m_pViews[nView]->Create(NULL, NULL,(AFX_WS_DEFAULT_VIEW & ~WS_VISIBLE),                             CRect(0,0,0,0), this,AFX_IDW_PANE_FIRST + nView, &newContext);         m_pViews [nView]->OnInitialUpdate();     } } void CMainFrame::SwapWindowID(const HWND& hWndFirst, const HWND& hWndSecond) {       //If GWL_ID then Retrieves the identifier of the window.       UINT nFirstWindow   = ::GetWindowLong(hWndFirst, GWL_ID);       UINT nSecondWindow  = ::GetWindowLong(hWndSecond, GWL_ID);       //Set Id of window.       ::SetWindowLong(hWndFirst, GWL_ID, nSecondWindow);       ::SetWindowLong(hWndSecond, GWL_ID, nFirstWindow); } void CMainFrame::SwitchView( ViewType viewType) {       ASSERT( viewType >=0 && viewType < TOTAL_NUM_VIEWS );       if ( viewType < 0 || viewType >= TOTAL_NUM_VIEWS )             return;       if (!m_pViews)             return;       CView* pNewView = m_pViews[viewType];             CView* pActiveView =GetActiveView();       if ( !pActiveView )    // No currently active view             return;       if ( pNewView == pActiveView )    // Already t  here             return;       //Swap ID's of Window.       SwapWindowID( pActiveView->m_hWnd, pNewView->m_hWnd);       pActiveView->ShowWindow(SW_HIDE);       pNewView->ShowWindow(SW_SHOW);       __super::SetActiveView(pNewView);       __super::RecalcLayout();       pNewView->Invalidate(); }
Steps : 1)In CwinApp call CMainFrame::InitViews() after ProcessShellCommand. 2) on switching Event call SwitchView() method. eg: SwitchView(DataBaseView);		1/oct/2008