{------------------------------------------------------------------------------
Unit : fisFileNotifaction.pas
Purpose : File notification component
Status :
Copyright: ?000 First Internet Software House,
http://www.fishouse.com Contact : support@fishouse.com
-------------------------------------------------------------------------------
History:
Date By Comments
---- ---- --------
30 July 2000 ME Created, converted from C++ Builder
}
unit fisFileNotification;
interface
uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
extctrls;
type
TDirThread = class(TThread)
private
prDirectory: String;
prKillEvent: THandle;
prSubTree: Boolean;
prNotifyFilter: DWORD;
prTimer: TTimer;
protected
procedure Execute; override;
public
constructor Create(aDirectory: String; aSubtree: Boolean;
aNotifyFilter: DWORD; aTimer: TTimer);
destructor Destroy; override;
end;
TNotifyOption = (noFilename, noDirname, noAttributes, noSize, noLastWrite, noLastAccess, noCreation);
TNotifyOptions = set of TNotifyOption;
TfisFileNotification = class(TComponent)
private
{ Private declarations }
prStarted: Boolean;
FSubtree: Boolean;
FOptions: TNotifyOptions;
FDirectory: String;
FOnDirectoryChanged: TNotifyEvent;
thrDirThread: TDirThread;
prTimer: TTimer;
protected
{ Protected declarations }
procedure Timer(Sender: TObject);
public
{ Public declarations }
constructor Create(aOwner: TComponent); override;
destructor Destroy; override;
procedure Start;
procedure Stop;
published
{ Published declarations }
property OnDirectoryChanged: TNotifyEvent read FOnDirectoryChanged write FOnDirectoryChanged;
property Subtree: Boolean read FSubtree write FSubtree;
property Directory: String read FDirectory write FDirectory;
property NotificationType: TNotifyOptions read FOptions write FOptions default [noLastWrite];
end;
procedure Register;
implementation
procedure Register;
begin
RegisterComponents('FISH', [TfisFileNotification]);
end;
{ TDirThread }
constructor TDirThread.Create(aDirectory: String; aSubtree: Boolean;
aNotifyFilter: DWORD; aTimer: TTimer);
begin
inherited Create(false);
prKillEvent := CreateEvent(nil, false, false, nil);
prDirectory := aDirectory;
prSubTree := aSubtree;
prNotifyFilter := aNotifyFilter;
prTimer := aTimer;
end;
destructor TDirThread.Destroy;
begin
SetEvent(prKillEvent);
CloseHandle(prKillEvent);
inherited;
end;
procedure TDirThread.Execute;
var
lObjList: array[0..1] of THandle;
NotifyRes: THandle;
begin
lObjList[0] := prKillEvent;
NotifyRes := FindFirstChangeNotification(Pchar(prDirectory), prSubTree,
prNotifyFilter);
lObjList[1] := NotifyRes;
if (NotifyRes <> INVALID_HANDLE_VALUE) then
begin
repeat
if(WaitForMultipleObjects(2, @lObjList, false, INFINITE) = WAIT_OBJECT_0) then
begin
break;
end;
prTimer.Enabled := true;
until not FindNextChangeNotification(lObjList[1]);
FindCloseChangeNotification(lObjList[1]);
end;
end;
{ TfisFileNotification }
constructor TfisFileNotification.Create(aOwner: TComponent);
begin
inherited;
FSubTree := False;
prStarted := False;
FDirectory := '';
FOptions := FOptions + [noLastWrite];
prTimer := TTimer.Create(Self);
prTimer.Enabled := False;
prTimer.Interval := 10;
prTimer.OnTimer := Timer;
end;
destructor TfisFileNotification.Destroy;
begin
if not (csDesigning in ComponentState) then
begin
Stop;
end;
inherited;
end;
procedure TfisFileNotification.Start;
var
lNotifyFilter: DWORD;
lItem: Integer;
begin
if (not prStarted) then
begin
lNotifyFilter := 0;
lItem := Integer(noFilename);
// Make file notification mask out of our enumerated type
while lItem <= integer(noCreation) do
begin
if TNotifyOption(lItem) in FOptions then
begin
lNotifyFilter := LNotifyFilter + (1 shl lItem);
end;
inc(lItem);
end;
thrDirThread := TDirThread.Create(FDirectory, FSubTree, lNotifyFilter, prTimer);
prStarted := True;
end;
end;
procedure TfisFileNotification.Stop;
begin
if prstarted then
begin
thrDirThread.free;
prStarted := False;
end;
end;
procedure TfisFileNotification.Timer(Sender: TObject);
begin
prTimer.Enabled := false;
if assigned(FOnDirectoryChanged) then
begin
FOnDirectoryChanged(self);
end;
end;
end.
--------------------
缺少DCR文件。以上的为pas文件。
