Detecting Up / Down arrows in CSpinButtonCtrl MFC C++

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.