private void CheckDrives(object sender, EventArgs e)
{
IEnumerable <char> currentDrives = GetCurrentDriveLetters();
int removedMask = DrivesToMask(_knownDrives.Except(currentDrives));
int addedMask = DrivesToMask(currentDrives.Except(_knownDrives));
removedMask |= DrivesToMask(_removedDrives);
addedMask |= DrivesToMask(_arrivedDrives);
_removedDrives.Clear();
_arrivedDrives.Clear();
_knownDrives = currentDrives;
if (removedMask > 0)
{
_monitor.TriggerEvents(false, removedMask);
}
if (addedMask > 0)
{
_monitor.TriggerEvents(true, addedMask);
}
}
/// <summary>
/// WndProc method that traps all messages sent to the Handle.
/// </summary>
/// <param name="msg">A Windows message.</param>
protected override void WndProc(ref Message msg)
{
base.WndProc(ref msg);
if (!_monitor.Enabled)
{
return;
}
if (msg.Msg == WM_DEVICECHANGE)
{
DeviceEvent evt = (DeviceEvent)msg.WParam.ToInt32();
if (evt == DeviceEvent.Arrival || evt == DeviceEvent.RemoveComplete)
{
BroadcastHeader broadcastHeader = (BroadcastHeader)Marshal.PtrToStructure(msg.LParam, typeof(BroadcastHeader));
if (broadcastHeader.Type == DeviceType.Volume)
{
Volume volume = (Volume)Marshal.PtrToStructure(msg.LParam, typeof(Volume));
if ((volume.Flags & (int)VolumeFlags.Media) != 0)
{
_monitor.TriggerEvents(evt == DeviceEvent.Arrival, volume.Mask);
}
}
}
}
}