private void UnregisterDeviceNotification(IntPtr deviceHandle, IntPtr fileHandle)
{
if (DeviceHandles.ContainsKey(deviceHandle))
{
SafeNativeMethods.CloseHandle(fileHandle);
SafeNativeMethods.UnregisterDeviceNotification(deviceHandle);
}
}
private void UnregisterDeviceNotification(IntPtr deviceHandle, IntPtr fileHandle)
{
if (DeviceHandles.ContainsKey(deviceHandle))
{
CloseHandle(fileHandle);
UnregisterDeviceNotification(deviceHandle);
}
}
private void ProcessMessage(Message message)
{
if (message.Msg == WM_DEVICECHANGE)
{
switch (message.WParam.ToInt32())
{
case DBT_DEVICEARRIVAL:
if (Marshal.ReadInt32(message.LParam, 4) == DBT_DEVTYP_VOLUME)
{
DEV_BROADCAST_VOLUME volume = Marshal.PtrToStructure <DEV_BROADCAST_VOLUME>(message.LParam);
string deviceName = DeviceMaskToDeviceName(volume.DBVC_UnitMask);
DeviceArrived?.Invoke(this, new DeviceNotificationEventArgs(deviceName));
RegisterDeviceNotification(deviceName);
}
break;
case DBT_DEVICEQUERYREMOVE:
if (Marshal.ReadInt32(message.LParam, 4) == DBT_DEVTYP_HANDLE)
{
DEV_BROADCAST_HANDLE data = Marshal.PtrToStructure <DEV_BROADCAST_HANDLE>(message.LParam);
if (DeviceHandles.ContainsKey(data.DBCH_HDevNotify))
{
DeviceQueryRemove?.Invoke(this, new DeviceNotificationEventArgs(DeviceHandles[data.DBCH_HDevNotify]));
}
UnregisterDeviceNotification(data.DBCH_HDevNotify, data.DBCH_Handle);
}
break;
case DBT_DEVICEREMOVECOMPLETE:
if (Marshal.ReadInt32(message.LParam, 4) == DBT_DEVTYP_VOLUME)
{
DEV_BROADCAST_VOLUME volume = Marshal.PtrToStructure <DEV_BROADCAST_VOLUME>(message.LParam);
string deviceName = DeviceMaskToDeviceName(volume.DBVC_UnitMask);
DeviceRemoveComplete?.Invoke(this, new DeviceNotificationEventArgs(deviceName));
}
break;
}
}
}