BCN_DROPDOWN notification code

Sent when the user clicks a drop down arrow on a button. The parent window of the control receives this notification code in the form of a WM_NOTIFY message.

BCN_DROPDOWN
        
    pnmdropdown = (NMBCDROPDOWN*) lParam;

Parameters

lParam

A pointer to a NMBCDROPDOWN structure. The rcButton member is set to describe the drop-down area.

Return value

No return value.

Remarks

The notification receiver casts LPARAM to retrieve the NMBCDROPDOWN structure. WPARAM contains the ID of the control that sends this message. The button control must have a drop-down button style.

Requirements