Delphi 监控文件改变

 

unit FileSysThread;interfaceuses  Windows, SysUtils, Classes, comctrls;type  TFileSysNotifyThread = class(TThread)  private    ErrCode: Integer;    KillAddress: PInteger;    NotifyHandle: THandle;    WatchPath: string;    WatchMask: Integer;    procedure SignalFileNotification;  protected    procedure Execute; override;  public    constructor Create(const AWatchPath: string; AWatchMask: Integer; var Myself: TFileSysNotifyThread);    destructor Destroy; override;  end;implementationuses Dialogs;constructor TFileSysNotifyThread.Create(const AWatchPath: string; AWatchMask: Integer; var Myself: TFileSysNotifyThread);begin  inherited Create(True);  WatchPath := AWatchPath;  WatchMask := AWatchMask;  KillAddress := Addr(Myself);  Priority := tpLower;  FreeOnTerminate := True;  Suspended := False;end;destructor TFileSysNotifyThread.Destroy;begin  if NotifyHandle <> THandle(-1) then    FindCloseChangeNotification(NotifyHandle);  inherited Destroy;  KillAddress^ := 0;end;procedure TFileSysNotifyThread.Execute;begin  NotifyHandle := FindFirstChangeNotification(PChar(WatchPath), True, WatchMask);  if NotifyHandle <> THandle(-1) then    while not Terminated do begin      ErrCode := WaitForSingleObject(NotifyHandle, 250);      case ErrCode of        Wait_Timeout:          ;        Wait_Object_0:          begin            Synchronize(SignalFileNotification);            FindNextChangeNotification(NotifyHandle);          end;      else ;      end;    end;end;procedure TFileSysNotifyThread.SignalFileNotification;begin  ShowMessage('文件已改变! ');end;end.