/// <summary>
/// New version which gets the handle automatically for specified directory
/// Only for registering! Unregister with the old version of this function...
/// </summary>
/// <param name="register"></param>
/// <param name="dirPath">e.g. C:\\dir</param>
private void RegisterForDeviceChange(string dirPath)
{
IntPtr handle = NativeMethods.OpenDirectory(dirPath);
if (handle == IntPtr.Zero)
{
this.deviceNotifyHandle = IntPtr.Zero;
return;
}
else
{
this.dirHandle = handle; // save handle for closing it when unregistering
}
// Register for handle
DEV_BROADCAST_HANDLE data = new DEV_BROADCAST_HANDLE {
dbch_devicetype = DBT_DEVTYP_HANDLE,
dbch_reserved = 0,
dbch_nameoffset = 0,
dbch_handle = handle,
dbch_hdevnotify = (IntPtr)0,
};
int size = Marshal.SizeOf(data);
data.dbch_size = size;
IntPtr buffer = Marshal.AllocHGlobal(size);
Marshal.StructureToPtr(data, buffer, true);
this.deviceNotifyHandle = NativeMethods.RegisterDeviceNotification(this.recipientHandle, buffer, 0);
}
/// <summary>
/// Registers to be notified when the volume is about to be removed
/// This is requierd if you want to get the QUERY REMOVE messages
/// </summary>
/// <param name="register">true to register, false to unregister</param>
/// <param name="fileHandle">handle of a file opened on the removable drive</param>
private void RegisterForDeviceChange(bool register, SafeFileHandle fileHandle)
{
if (register)
{
// Register for handle
DEV_BROADCAST_HANDLE data = new DEV_BROADCAST_HANDLE {
dbch_devicetype = DBT_DEVTYP_HANDLE,
dbch_reserved = 0,
dbch_nameoffset = 0,
dbch_handle = fileHandle.DangerousGetHandle(),
dbch_hdevnotify = (IntPtr)0,
};
int size = Marshal.SizeOf(data);
data.dbch_size = size;
IntPtr buffer = Marshal.AllocHGlobal(size);
Marshal.StructureToPtr(data, buffer, true);
this.deviceNotifyHandle = NativeMethods.RegisterDeviceNotification(this.recipientHandle, buffer, 0);
}
else
{
// close the directory handle
if (this.dirHandle != IntPtr.Zero)
{
NativeMethods.CloseDirectoryHandle(this.dirHandle);
}
// unregister
if (this.deviceNotifyHandle != IntPtr.Zero)
{
_ = NativeMethods.UnregisterDeviceNotification(this.deviceNotifyHandle);
}
this.deviceNotifyHandle = IntPtr.Zero;
this.dirHandle = IntPtr.Zero;
this.currentDrive = string.Empty;
this.fileOnFlash?.Close();
this.fileOnFlash = null;
}
}
