Loading bitmap image to button - c++

Question

I am working on legacy application, i added a button(Switch/pushlike) to a dialog i want to add bitmap image to that, to get the reference there is getdlgitem(id) but here this function is also demanding hwnd object,
on searching the code i found previously they used following three functions
environ_control->dialwindow
environ_get_active_dialogue()
environ_get_ActiveWindow()
to pass in the place of hwnd, none of them is working for me,
i tried it like this
CButton* pButton = (CButton*)GetDlgItem(environ_get_active_dialogue(),IDD_BTN_CUSTOMRANDC );
pButton->SetBitmap((HBITMAP)Bmp1);
It gives debug assertion failed on second line, any help please, the function code is
SYMBOLIC JOB_PSNUP::nup_init_nup_dialog( void )
{
int arrTabs[8];
arrTabs[0] = 6;
arrTabs[1] = 28;
arrTabs[2] = 61;
arrTabs[3] = 97;
arrTabs[4] = 137;
arrTabs[5] = 179;
arrTabs[6] = 218;
// Reset information about Preview area
m_hwndPreview = NULL;
m_hdcPreview = NULL;
m_rFront.top = m_rFront.bottom = m_rFront.left = m_rFront.right = 0;
m_rBack.top = m_rBack.bottom = m_rBack.left = m_rBack.right = 0;
CBitmap Bmp1, Bmp2;
m_bSetOrderMode = FALSE;
m_iCurrOrder = 1;
environ_set_dlg_item_text_win( IDD_SNAME, "<click on page>" );
CDataExchange dx(CWnd::FromHandle(environ_get_active_dialogue()), FALSE);
ELX_INT BtnIndex;
comm->m_pXPBtn[BtnIndex = comm->GetIndexForNewBtn()] = new ECXPStyleButton;
comm->m_pXPBtn[comm->GetIndexForNewBtn()] = new ECXPStyleButton;
comm->initXPBtn(comm->m_pXPBtn[BtnIndex+0], IDD_NUMOVEUP, &dx, IDB_MOVEUP, "Move up");
comm->initXPBtn(comm->m_pXPBtn[BtnIndex+1], IDD_NUMOVEDOWN, &dx, IDB_MOVEDOWN, "Move down");
ECListCtrl* pListCtrl = comm->InitECListCtrl(IDD_NULIST, _T("Order,70;Side,50;Number,60;H.Offset,60;V.Offset,60;Constant,60;Forms,50"));
pListCtrl->GetHeaderCtrl()->EnableWindow(FALSE);
comm->state.enSortBy2 = SORT_DOC_BY_NAME_ASC;
environ_set_resource_object_state( 0, IDD_NUCURRORDER, OBJECT_STATE_DISABLED, FALSE );
environ_set_resource_object_state( 0, IDD_NUORDERLAB, OBJECT_STATE_DISABLED, FALSE );
environ_message_handler( ENVIRON_LBSET_TAB_STOPS, (void*)IDD_NULIST, (void*)(&arrTabs));
environ_message_handler( ENVIRON_LBSET_HEXTENT, (void*)IDD_NULIST, (void*)(1000) );
comm->dial.dial_stack_fake[0] = '\0';
environ_set_string_into_resource_object( 0, IDD_NUHOFFSET, comm->dial.dial_stack_fake, FALSE );
Bmp1.LoadBitmapA(IDB_BUTTON_ON);
Bmp2.LoadBitmapA(IDB_BUTTON_OFF);
if( environ_is_object_selected( 0, IDD_BTN_CUSTOMRANDC ))
{
CButton* pButton = (CButton*)GetDlgItem(environ_get_active_dialogue(),IDD_BTN_CUSTOMRANDC );
pButton->SetBitmap((HBITMAP)Bmp2);
}
else
{
CButton* pButton = (CButton*)GetDlgItem(environ_get_active_dialogue(),IDD_BTN_CUSTOMRANDC );
pButton->SetBitmap((HBITMAP)Bmp1);
}
// Total number of partitions
environ_set_dlg_item_int_win( IDD_NUTOTNUM, m_iTotal );
// On Back side
if( m_enPaperDuplex == JOB_SIMPLEX )
{
environ_set_resource_object_state( 0, IDD_NUFRONTNUMLAB, OBJECT_STATE_HIDDEN, FALSE );
environ_set_resource_object_state( 0, IDD_NUFRONTNUM, OBJECT_STATE_HIDDEN, FALSE );
environ_set_resource_object_state( 0, IDD_NUBACKNUMLAB, OBJECT_STATE_HIDDEN, FALSE );
environ_set_resource_object_state( 0, IDD_NUBACKNUM, OBJECT_STATE_HIDDEN, FALSE );
environ_set_resource_object_state( 0, IDD_NUFRONTLAB, OBJECT_STATE_HIDDEN, FALSE );
environ_set_resource_object_state( 0, IDD_NUBACKLAB, OBJECT_STATE_HIDDEN, FALSE );
environ_set_dlg_item_text_win( IDD_NUTOTNUMLAB, "&Number of Partitions:" );
}
else
{
environ_set_dlg_item_int_win( IDD_NUFRONTNUM, m_iOnFront );
environ_set_dlg_item_int_win( IDD_NUBACKNUM, m_iOnBack );
}
// Offset units
comm->job_prop->jobprop_get_unit_name( comm->formdef.props.units, FALSE/*TRUE*/, comm->state.workstring ); // SMP
environ_set_dlg_item_text_win( IDD_UNITSTR0, comm->state.workstring );
environ_set_dlg_item_text_win( IDD_UNITSTR1, comm->state.workstring );
if( comm->job_config.flag.auto_offset_paper_partitions )
{
environ_set_resource_object_on_or_off( 0, IDD_NUAUTOOFFSET, TRUE );
}
// List of Partitions
nup_fill_list();
m_NupDialExit = USER_CANCEL;
return( 0 );
}

Answer 1

The version of GetDlgItem that takes two parameters returns an HWND, not a CWnd*. So it is incorrect to cast it to CButton*. Instead, use GetDlgItem(IDD_BTN_CUSTOMRANDC).