[RESOLVED] Laptop "Lid Close Test"

[penagate]

A bit more time Googling led me to this MSDN forum thread:
http://social.msdn.microsoft.com/For...-016b57211b3a/

In short: You need to call RegisterPowerSettingNotification to receive the power state messages. Pass a window handle for the first parameter and DEVICE_NOTIFY_WINDOW_HANDLE (0) for the third. The second parameter is a GUID structure (use System.GUID in .NET) representing GUID_LIDSWITCH_STATE_CHANGE:

0xBA3E0F4D, 0xB817, 0x4094, 0xA2, 0xD1, 0xD5, 0x63, 0x79, 0xE6, 0xA0, 0xF3

The type of message that you need to trap is WM_POWERBROADCAST (0x218).
The event type (wParam) is PBT_POWERSETTINGCHANGE (0x8013). Use an overriden WndProc to trap the message.

Here is some more information:
Trapping the WM_POWERBROADCAST Window Message

This all requires Windows Vista or later, by the way.