中的定义如下：
Function SHChangeNotifyRegister(hWnd,uFlags,dwEventID,uMSG,cItems:LongWord;
lpps:PIDLSTRUCT):integer;stdcall;external ''Shell32.dll'' index 2;
其中参数hWnd定义了监视系统操作的窗口得句柄，参数uFlags dwEventID定义监视操作参数，参数uMsg定义操作消息，参数cItems
定义附加参数，参数lpps指定一个PIDLSTRUCT结构，该结构指定监视的目录。
当函数调用成功之后，函数会返回一个监视操作句柄，同时系统就会将hWnd指定的窗口加入到操作监视链中，当有文件操作发生
时，系统会向hWnd发送uMsg指定的消息，我们只要在程序中加入该消息的处理函数就可以实现对系统操作的监视了。
如果要退出程序监视，就要调用另外一个未公开得函数SHChangeNotifyDeregister来取消程序监视。
下面是使用Delphi编写的具体程序实现范例，首先建立一个新的工程文件，然后在Form1中加入一个Button控件和一个Memo控件，
程序的代码如下：
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
StdCtrls,shlobj,Activex;
const
SHCNE_RENAMEITEM = $1;
SHCNE_CREATE = $2;
SHCNE_DELETE = $4;
SHCNE_MKDIR = $8;
SHCNE_RMDIR = $10;
SHCNE_MEDIAINSERTED = $20;
SHCNE_MEDIAREMOVED = $40;
SHCNE_DRIVEREMOVED = $80;
SHCNE_DRIVEADD = $100;
SHCNE_NETSHARE = $200;
SHCNE_NETUNSHARE = $400;
SHCNE_ATTRIBUTES = $800;
SHCNE_UPDATEDIR = $1000;
SHCNE_UPDATEITEM = $2000;
SHCNE_SERVERDISCONNECT = $4000;
SHCNE_UPDATEIMAGE = $8000;
SHCNE_DRIVEADDGUI = $10000;
SHCNE_RENAMEFOLDER = $20000;
SHCNE_FREESPACE = $40000;
SHCNE_ASSOCCHANGED = $8000000;
SHCNE_DISKEVENTS = $2381F;
SHCNE_GLOBALEVENTS = $C0581E0;
SHCNE_ALLEVENTS = $7FFFFFFF;
SHCNE_INTERRUPT = $80000000;
SHCNF_IDLIST = 0; // LPITEMIDLIST
SHCNF_PATHA = $1; // path name
SHCNF_PRINTERA = $2; // printer friendly name
SHCNF_DWORD = $3; // DWORD
SHCNF_PATHW = $5; // path name
SHCNF_PRINTERW = $6; // printer friendly name
SHCNF_TYPE = $FF;
SHCNF_FLUSH = $1000;
SHCNF_FLUSHNOWAIT = $2000;
SHCNF_PATH = SHCNF_PATHW;
SHCNF_PRINTER = SHCNF_PRINTERW;
WM_SHNOTIFY = $401;
NOERROR = 0;
type
TForm1 = class(TForm)
Button1: TButton;
Memo1: TMemo;
procedure FormClose(Sender: TObject; var Action: TCloseAction);
pro