Derive a new class from cedit that only allows the input of hexadecimal data

// Derive a new class from cedit that only allows the input of hexadecimal data
// Enter space 0-F backspace
// Switch the Input Method to the English keyboard during activation
// Restore the input method when the focus is lost
// A warning message is prompted in case of invalid characters
 

# Pragma once // chexeditctrlclass chexeditctrl: Public cedit {declare_dynamic (chexeditctrl) Public: chexeditctrl (); Virtual ~ Chexeditctrl (); protected: afx_msg void onensetfocus (); afx_msg void encrypt (); encrypt () virtual lresult windowproc (uint message, wparam, lparam); // input protected: HKL m_defaulthkl; HKL m_saved_kbdlayout; HKL getdefault_kbdlayout ();};

 

// Hexeditctrl. CPP: implementation file // # include "stdafx. H "# include" hexeditctrl. H "// decrypt (chexeditctrl, cedit) chexeditctrl: chexeditctrl () {m_defaulthkl = getdefault_kbdlayout (); m_saved_kbdlayout = 0;} chexeditctrl ::~ Chexeditctrl () {}← (chexeditctrl, cedit) ← (en_setfocus, & chexeditctrl: onensetfocus) ← (en_killfocus, & chexeditctrl: onenkillfocus) end_message_map () // chexeditctrl message handlerslresult chexeditctrl: windowproc (uint message, wparam, lparam) {// todo: add your specialized code here and/or call the base class // filter other characters // allow spaces 0-f backspaceif (M Essage = wm_char) {wchar szinput [2] = {(wchar) wparam, 0}; _ tcsupr_s (szinput); cstringw szvaliditem = l "0123456789abcdef \ B "; if (szvaliditem. find (szinput) =-1) {messagebeep (-1); // return 0;} wparam = szinput [0];} If (wm_inputlangchangerequest = message) // switch the input method message {return 0; // lock the input method // m_saved_kbdlayout = 0; // accept the change and do not need to restore the input method} return cedit: windowproc (message, wparam, lparam);} void chexeditctrl: onenset Focus () {// todo: add your control notification handler code hereif (m_defaulthkl) {HKL curkbdlayout = getkeyboardlayout (0); If (curkbdlayout! = M_defaulthkl) {m_saved_kbdlayout = curkbdlayout; // Save the input method if (activatekeyboardlayout (m_defaulthkl, 0) = 0) // set the Default Input Method to {trace (_ T ("set activatekeyboardlayout err = % d"), getlasterror () ;}}} void chexeditctrl: onenkillfocus () {// todo: add your control notification handler code hereif (m_saved_kbdlayout) // restore Input Method {If (activatekeyboardlayout (m_saved_kbdlayout, 0) = 0) trace (_ T ("Restore activatekey Boardlayout err = % d "), getlasterror (); m_saved_kbdlayout = 0 ;}// obtain the English keyboard HKL chexeditctrl: getdefault_kbdlayout () {HKL hkl_ret = 0; int nsize = getkeyboardlayoutlist (0, 0); If (nsize! = 0) {HKL far * lplist = (hkl far *) New HKL [nsize]; zeromemory (lplist, sizeof (hkl) * nsize); If (getkeyboardlayoutlist (nsize, lplist) = nsize) {for (INT I = 0; I <nsize; I ++) {HKL val = lplist [I]; If (hiword (VAL) = loword (VAL) hkl_ret = val; trace (_ T ("0x % 08x/N"), Val) ;}delete [] lplist;} return hkl_ret ;}

// Application example

// Mfc_1dlg.h: header file // # pragma once # include "hexeditctrl. H "// cmfc_dlg dialog box class cmfc_dlg: Public cdialog {protected: chexeditctrl m_edit; virtual void dodataexchange (cdataexchange * PDX); // DDX/DDV support

 

// Mfc_1dlg.cpp: implementation file // void cmfc_dlg: dodataexchange (cdataexchange * PDX) {cdialog: dodataexchange (PDX); ddx_control (PDX, idc_edit, m_edit );}