Detecting Up / Down arrows in CSpinButtonCtrl MFC C++ - mfc

Question

Is there any way to differentiate when the Up or Down arrow of a CSpinButtonCtrl is pressed?
I am trying to use the OnPointerdown event, but I don't know how to do it...
afx_msg LRESULT CMySpinButtonCtrl::OnPointerdown(WPARAM wParam, LPARAM lParam)
{
if(IS_POINTER_PRIMARY_WPARAM(wParam))
{
//TODO
}
return 0;
}
I will appreciate any kind of help.

Answer 1

Is there any way to differentiate when the Up or Down arrow of a CSpinButtonCtrl is pressed?
You should use UDN_DELTAPOS to do this.
Right-click the control in the Resource Editor and select Add Event Handler:
Select the UDN_DELTAPOS message and click Add and Edit:
You will be provided with skeleton code:
void CMFCApplication1Dlg::OnDeltaposSpin1(NMHDR *pNMHDR, LRESULT *pResult)
{
LPNMUPDOWN pNMUpDown = reinterpret_cast<LPNMUPDOWN>(pNMHDR);
// TODO: Add your control notification handler code here
*pResult = 0;
}
The NMUPDOWN article explains about the structure that you use. What you need to do is test the iDelta value. Example:
void CColumnOrderDlg::OnDeltaposSpinColumns(NMHDR* pNMHDR, LRESULT* pResult)
{
LPNMUPDOWN pNMUpDown = reinterpret_cast<LPNMUPDOWN>(pNMHDR);
if (pNMUpDown != nullptr)
{
if( pNMUpDown->iDelta > 0)
// Up - Do stuff;
else if(pNMUpDown->iDelta < 0)
// Down - Do stuff;
}
*pResult = 0;
}
There is also a useful article here where it states:
If you use a spin control for some other purpose, for example, to page through a sequence of windows or dialog boxes, then add a handler for the UDN_DELTAPOS message and perform your custom action there.