Modal common dialogs

Most of the Common dialog boxes like File open/save, font, color, page setup, print dialog etc opens on top on main window and takes the user input and then closes. User cannot interact with main window and the control jumps to the event procedure of popup dialog. It returns to main event when user selects okay or cancel and dialog returns. This type of dialogs are modal dialog box.

Modeless find replace

Find replace dialog is different than these dialogs. It takes user's input at the same time user can interact with the main window where the search is happening. This type of dialog is modeless dialog box. The processing happens in different GUI thread and user can switch between main dialog and this popup dialog.

Source Code

#include <afxwin.h>
#include <afxdlgs.h>

class CMyWnd : public CFrameWnd
{
  CFindReplaceDialog m_FindReplace;
  CEdit m_Edit;
  public:
    CMyWnd()
    {
      RECT rect;
      Create(NULL, _T("FindReplace demo"));
      GetClientRect(&rect);
      m_Edit.Create(ES_MULTILINE | WS_CHILD | WS_VISIBLE | WS_TABSTOP | WS_BORDER, rect, this, 100);
      m_FindReplace.Create(FALSE, "find", "replace", FR_DOWN, this);
      m_Edit.SetWindowText("This is a find replace demo.");
    }
    afx_msg void CMyWnd::OnClose()
    DECLARE_MESSAGE_MAP()
};

BEGIN_MESSAGE_MAP(CMyWnd, CFrameWnd)
ON_WM_CLOSE()
END_MESSAGE_MAP()

afx_msg void CMyWnd::OnClose()
{
  if(MessageBox ("Want to exit from this application?", "Exit", MB_YESNO) == IDYES)
  {
     PostQuitMessage(0);
  }
}
 
class CMyApp : public  CWinApp 
{

  public:
     virtual BOOL InitInstance()
    {
      m_pMainWnd = new CMyWnd();
      m_pMainWnd->ShowWindow(SW_SHOW);
      m_pMainWnd->UpdateWindow();
      return TRUE;
    }
 };
CMyApp app;

Output

Find replace modeless dialog

About our authors: Team EQA

Further readings

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DispatchMessage() is a API which indirectly triggers the Window CallBack procedure. Message structure members from this function are passed to the CallBack procedure. CallBack procedure should implement event handlers depending on the need of the application.

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What are the basic steps of a typical MFC based application?

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