c++ - CInvalidArgumentException when checking class in PreTranslateMessage -

the case: i'd make shortcuts numpad users can use application fast. implemented in pretranslatemessage , worked.

but case have edit control user should enter number. @ time user has focus on edit control (cedit), shortcuts should disabled.

to cover this, added

cwnd* pcontrol; pcontrol = this->getfocus(); if(!(pcontrol->iskindof(runtime_class(cedit)))){ 

but whenever application dialog loses focus, closes (see video) , following exeption:

this full code:

// handles keypresses fast acces of functions bool copenfilesdlg::pretranslatemessage(msg *pmsg){     cwnd* pcontrol;     pcontrol = this->getfocus();     if(!(pcontrol->iskindof(runtime_class(cedit)))){ //when statement commented program doesn't crash         if(pmsg->message == wm_keydown)         {             if((pmsg->wparam == 0x31 || pmsg->wparam == vk_numpad1))                 somefunction();             else if((pmsg->wparam == 0x33 || pmsg->wparam == vk_numpad3)){                 someotherfunction();             }         }     }             return cdialog::pretranslatemessage(pmsg); } 

now question: why program crash when not in focus , how check if focus on edit control in proper way?

cwnd::getfocus returns pointer window has current focus, or null if there no focus window.

pcontrol = this->getfocus(); if ( pcontrol != null ) {     if(!(pcontrol->iskindof(runtime_class(cedit))))     ... } 

another way compare pcontrol value pointer cedit class member (or members) of dialog class. example, if cedit m_edit edit box class member, test:

if ( pcontrol == (cwnd*)&m_edit ) {     // focus on m_edit control }