Step 8. Apply Property Changes

Override the CBasePropertyPage::OnApplyChanges method to commit any property changes. In this example, the m_lNewVal variable is updated whenever the user scrolls the slider bar. The OnApplyChanges method copies this value into the m_lVal variable, overwriting the original value:

HRESULT CGrayProp::OnApplyChanges(void)
{
    m_lVal = m_lNewVal;
    return S_OK;
}