另一种界面闪烁解决方案

      基于贴图的界面中，为了实现界面的统一，一种方法就是所有界面类派上自一个贴图的基类，而基类中一般是进行最基本的贴图，派生类中多数会进行自己的其他绘制，这时如果不进行特殊处理必然会出现闪烁，因为基类和派生类不是一起绘制的，这里介绍一种方案避免闪烁，具体实现参看代码：

下面是基类，只是象征性的绘制了下：

#include <atlgdi.h> #include <atlmisc.h> template <class T> class ATL_NO_VTABLE CFlickFreeBaseDlg : public CDialogImpl<T> { BEGIN_MSG_MAP_EX(CFlickFreeBaseDlg) MSG_WM_PAINT(OnPaint) MSG_WM_ERASEBKGND(OnEraseBkgnd) END_MSG_MAP() public: CFlickFreeBaseDlg():m_pMemDC(NULL) { } ~CFlickFreeBaseDlg() { if (m_pMemDC) { delete m_pMemDC; m_pMemDC=NULL; } } protected: void OnPaint(CDCHandle dc) { GetClientRect(&m_rcClient); CPaintDC dcPaint(m_hWnd); if (NULL==m_pMemDC) { m_pMemDC=new CMemoryDC(dcPaint,m_rcClient); } //Do Base Paint m_pMemDC->FillSolidRect(m_rcClient,RGB(0,100,255)); m_pMemDC->DrawText(_T("Draw In Base"),-1,CRect(0,0,80,20),DT_SINGLELINE|DT_VCENTER); static_cast<T*>(this)->DerivingDraw(); delete m_pMemDC; m_pMemDC=NULL; } BOOL OnEraseBkgnd(CDCHandle dc) { return TRUE; } protected: CRect m_rcClient; CMemoryDC *m_pMemDC; };

下面是派生类代码：

#include "FlickFreeBase.h" class CMainDlg : public CFlickFreeBaseDlg<CMainDlg>, public CUpdateUI<CMainDlg>, public CMessageFilter, public CIdleHandler { public: enum { IDD = IDD_MAINDLG }; virtual BOOL PreTranslateMessage(MSG* pMsg) { return CWindow::IsDialogMessage(pMsg); } virtual BOOL OnIdle() { return FALSE; } BEGIN_UPDATE_UI_MAP(CMainDlg) END_UPDATE_UI_MAP() BEGIN_MSG_MAP(CMainDlg) CHAIN_MSG_MAP(CFlickFreeBaseDlg<CMainDlg>) MESSAGE_HANDLER(WM_INITDIALOG, OnInitDialog) MESSAGE_HANDLER(WM_DESTROY, OnDestroy) COMMAND_ID_HANDLER(ID_APP_ABOUT, OnAppAbout) COMMAND_ID_HANDLER(IDOK, OnOK) COMMAND_ID_HANDLER(IDCANCEL, OnCancel) END_MSG_MAP() // Handler prototypes (uncomment arguments if needed): // LRESULT MessageHandler(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM /*lParam*/, BOOL& /*bHandled*/) // LRESULT CommandHandler(WORD /*wNotifyCode*/, WORD /*wID*/, HWND /*hWndCtl*/, BOOL& /*bHandled*/) // LRESULT NotifyHandler(int /*idCtrl*/, LPNMHDR /*pnmh*/, BOOL& /*bHandled*/) LRESULT OnInitDialog(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM /*lParam*/, BOOL& /*bHandled*/) { // center the dialog on the screen CenterWindow(); // set icons HICON hIcon = (HICON)::LoadImage(_Module.GetResourceInstance(), MAKEINTRESOURCE(IDR_MAINFRAME), IMAGE_ICON, ::GetSystemMetrics(SM_CXICON), ::GetSystemMetrics(SM_CYICON), LR_DEFAULTCOLOR); SetIcon(hIcon, TRUE); HICON hIconSmall = (HICON)::LoadImage(_Module.GetResourceInstance(), MAKEINTRESOURCE(IDR_MAINFRAME), IMAGE_ICON, ::GetSystemMetrics(SM_CXSMICON), ::GetSystemMetrics(SM_CYSMICON), LR_DEFAULTCOLOR); SetIcon(hIconSmall, FALSE); // register object for message filtering and idle updates CMessageLoop* pLoop = _Module.GetMessageLoop(); ATLASSERT(pLoop != NULL); pLoop->AddMessageFilter(this); pLoop->AddIdleHandler(this); UIAddChildWindowContainer(m_hWnd); return TRUE; } LRESULT OnDestroy(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM /*lParam*/, BOOL& /*bHandled*/) { // unregister message filtering and idle updates CMessageLoop* pLoop = _Module.GetMessageLoop(); ATLASSERT(pLoop != NULL); pLoop->RemoveMessageFilter(this); pLoop->RemoveIdleHandler(this); return 0; } LRESULT OnAppAbout(WORD /*wNotifyCode*/, WORD /*wID*/, HWND /*hWndCtl*/, BOOL& /*bHandled*/) { CAboutDlg dlg; dlg.DoModal(); return 0; } LRESULT OnOK(WORD /*wNotifyCode*/, WORD wID, HWND /*hWndCtl*/, BOOL& /*bHandled*/) { // TODO: Add validation code CloseDialog(wID); return 0; } LRESULT OnCancel(WORD /*wNotifyCode*/, WORD wID, HWND /*hWndCtl*/, BOOL& /*bHandled*/) { CloseDialog(wID); return 0; } void CloseDialog(int nVal) { DestroyWindow(); ::PostQuitMessage(nVal); } void DerivingDraw() { m_pMemDC->FillSolidRect(CRect(100,50,400,300),RGB(119,173,2)); m_pMemDC->DrawText(_T("Draw In Deriving"),-1,CRect(100,50,400,300),DT_SINGLELINE|DT_VCENTER); } };