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;
      RECT rect;
      Create(NULL, _T("FindReplace demo"));
      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()


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

     virtual BOOL InitInstance()
      m_pMainWnd = new CMyWnd();
      return TRUE;
CMyApp app;


Find replace modeless dialog

About our authors: Team EQA

Further readings

Where is WinMain() function in MFC application ?

MFC hides WinMain in its framework and includes source file on WinMain(). This explains how framework calls global CWinApp::Initinstance() from entry WinMain.

What is the utility of CWinApp class?

This is constructed during global C++ objects are constructed and is already available when Windows calls the WinMain function, which is supplied by the ...

Basic steps in Win32 GUI Application with source code.

Define a custom Window class structure, Register the class name, CreateWindow, Show windows and write message get and dispatch loop statements. Define the Window CallBack procedure and write the handlers.

What is a Window CallBack procedure and what is its utility?

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.

What are LPARAM and WPARAM in window proc function?

LPARAM and WPARAM are the two parameters in Window CallBack procedure. They signifies parameters of various events. They are used in handing individual events.

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

We need to write WinMain and need to follow all these in a Win32 application. However we need not to write much if we are writing an application with MFC ...