一个关于 Windows Message 的问题 from 3h(300分)

3h · 1999-09-29

试了一下，基本能用，它能够捕获文件系统的变化，不过结果很简单，就只一个事件， ONCHANGE。 它也只有两个参数：sender和所在目录。 如果象资源管理器一样能够知道是那一个文件就好了。

cmxu · 1999-09-30

用COM对象, 实现诸如 ICopyHook之类的接口可以截获很多功能, Delphi有一个 Demo, 就是CopyHook的.

hubdog · 1999-10-03

cmxu说的对，这属于shell扩展，Delphi的/demo/Activex/shellext/下

delphiwolf · 1999-10-03

关注

3h · 1999-10-03

最好有例程。

张磊 · 1999-10-12

//faint. Delphi的方法与这个SysMonitor的方法是不一样的. 在Windows下面要监控一个目录只能用Another_eYes的方法,即是 调用CreateFile与CreateCompletionPort的方法来做,然后用 FindFirstChangeNotification FindNextChangeNotification 来得知目录的变化. 在WinNT下面有一个很好的函数叫ReadDirectoryChangesW 函数,调用以下函数: CreateFile CreateCompletionPort ReadDirectoryChangesW GetOverLappedResult 这几个函数就可以创建一个线程来监控一个目录了, 而且可以得到很详细的信息. SysMonitor用的是Another_eYes的方法,但是如果你在NT下面, 则可以自己写一个监控线程,很容易的.

张磊 · 1999-10-12

现在我吧代码贴上来吧: DiscMonitor: // ==================== DISC DRIVE MONITOR ===================================== // // Class and Component to encapsulate the FindXXXXChangeNotification API calls // // The FindXXXXChangeNotification API calls set up a disc contents change // notification handle.  You can set a filter to control which change types // are notified, the directory which is monitored and set whether subdirectories // from the monitored directory are monitored as well. // //------------------------------------------------------------------------------ // This file contains a class derived from TThread which undertakes the disc // monitoring and a simple component which encapsulates the thread to make // a non-visual VCL component.  This component works at design time, monitoring // and notifying changes live if required. // // Version 1.00 - Grahame Marsh 14 January 1997 // Version 1.01 - Grahame Marsh 30 December 1997 //      Bug fix - really a Win 95 bug but only surfaces in D3, not D2 //              - see notes in execute method // Version 1.02 - Grahame Marsh 30 January 1998 //              - adapted to work with version 2.30 TBrowseDirectoryDlg // // Freeware - you get it for free, I take nothing, I make no promises! // // Please feel free to contact me: grahame.s.marsh@courtaulds.com unit DiscMon; interface uses   Windows, Messages, SysUtils, Classes, Graphics, Controls,   Forms, Dialogs, ShlObj{, BrowseDr, DsgnIntf ie02}; //=== DISC MONITORING THREAD =================================================== // This thread will monitor a given directory and subdirectories (if required) // for defined filtered changes.  When a change occurs the OnChange event will // be fired, if an invalid condition is found (eg non-existent path) then // the OnInvalid event is fired. Each event is called via the Sychronize method // and so are VCL thread safe. // // The thread is created suspended, so after setting the required properties // you must call the Resume method. type   TDiscMonitorThread = class(TThread)   private     FOnChange : TNotifyEvent;     FOnInvalid : TNotifyEvent;     FDirectory : string;     FFilters : integer;     FDestroyEvent,     FChangeEvent : THandle;     FSubTree : boolean;     fChangeDelay : Integer;  {ie01}     procedure InformChange;     procedure InformInvalid;     procedure SetDirectory (const Value : string);     procedure SetFilters (Value : integer);     procedure SetSubTree (Value : boolean);   protected     procedure Execute; override;     procedure Update;   public     constructor Create;     destructor Destroy; override; // The directory to monitor     property Directory : string read FDirectory write SetDirectory; // Filter condition, may be any of the FILE_NOTIFY_CHANGE_XXXXXXX constants // ORed together.  Zero is invalid.     property Filters : integer read FFilters write SetFilters; // Event called when change noted in directory     property OnChange : TNotifyEvent read FOnChange write FOnChange; // Event called for invalid parameters     property OnInvalid : TNotifyEvent read FOnInvalid write FOnInvalid; // Include subdirectories below specified directory.     property SubTree : boolean read FSubTree write SetSubTree; // specify, how long the thread should wait, before the event OnChange is fired:     Property ChangeDelay : Integer Read fChangeDelay Write fChangeDelay  {ie01}                                    Default 500;                          {ie01}   end; //===================== DISC MONITORING COMPONENT ============================== // specify directory string as type string so we can have our own property editor   TDiscMonitorDirStr = type string; // enumerated type for filter conditions (not directly usable in thread class) // see the SetFilters procedure for the translation of these filter conditions // into FILE_NOTIFY_CHANGE_XXXXXX constants.   TMonitorFilter = (moFilename, moDirName, moAttributes, moSize,                     moLastWrite, moSecurity); // set of filter conditions   TMonitorFilters = set of TMonitorFilter;   TDiscMonitor = class(TComponent)   private     FActive : boolean;     FMonitor : TDiscMonitorThread;     FFilters : TMonitorFilters;     FOnChange : TNotifyEvent;     FOnInvalid : TNotifyEvent;     FShowMsg : boolean;     function GetDirectory : TDiscMonitorDirStr;     function GetSubTree : boolean;     procedure SetActive (Value : boolean);     procedure SetDirectory (Value : TDiscMonitorDirStr);     procedure SetFilters (Value : TMonitorFilters);     procedure SetSubTree (Value : boolean);     Function  GetChangeDelay : Integer;         {ie01}     Procedure SetChangeDelay(Value : Integer);  {ie01}   protected     procedure Change (Sender : TObject);     procedure Invalid (Sender : TObject);   public     constructor Create (AOwner : TComponent);  Override;     destructor Destroy; override; // stop the monitoring thread running     procedure Close; // start the monitoring thread running     procedure Open; // read-only property to access the thread directly     property Thread : TDiscMonitorThread read FMonitor;   published // the directory to monitor     property Directory : TDiscMonitorDirStr read GetDirectory write SetDirectory; // control the appearance of information messages at design time (only)     property ShowDesignMsg : boolean read FShowMsg write FShowMsg default false; // event called when a change is notified     property OnChange : TNotifyEvent read FOnChange write FOnChange; // event called if an invalid condition is found     property OnInvalid : TNotifyEvent read FOnInvalid write FOnInvalid; // notification filter conditions     property Filters : TMonitorFilters read FFilters write SetFilters default [moFilename]; // include subdirectories below the specified directory     property SubTree : boolean read GetSubTree write SetSubTree default true; // specify if the monitoring thread is active     property Active : boolean read FActive write SetActive default false; // specify, how long the thread should wait, before the event OnChange is fired:     Property ChangeDelay : Integer Read GetChangeDelay Write SetChangeDelay  {ie01}                                    Default 500;                              {ie01}   end; procedure Register; implementation //=== MONITOR THREAD =========================================================== // Create the thread suspended.  Create two events, each are created using // standard security, in the non-signalled state, with auto-reset and without // names.  The FDestroyEvent will be used to signal the thread that it is to close // down.  The FChangeEvent will be used to signal the thread when the monitoring // conditions (directory, filters or sub-directory search) have changed. // OnTerminate is left as false, so the user must Free the thread. constructor TDiscMonitorThread.Create; begin   inherited Create (true);   FDestroyEvent := CreateEvent (nil, true,  false, NIL);   FChangeEvent  := CreateEvent (nil, false, false, NIL); end; // close OnXXXXX links, signal the thread that it is to close down destructor TDiscMonitorThread.Destroy; begin   FOnChange := nil;   FOnInvalid := nil;   SetEvent (FDestroyEvent);   FDirectory := '';   inherited Destroy end; // called by the Execute procedure via Synchronize.  So this is VCL thread safe procedure TDiscMonitorThread.InformChange; begin   if Assigned (FOnChange) then     FOnChange (Self) end; // called by the Execute procedure via Synchronize.  So this is VCL thread safe procedure TDiscMonitorThread.InformInvalid; begin   if Assigned (FOnInvalid) then     FOnInvalid (Self) end; // Change the current directory procedure TDiscMonitorThread.SetDirectory (const Value : string); begin   if Value <> FDirectory then   begin     FDirectory := Value;     Update   end end; // Change the current filters procedure TDiscMonitorThread.SetFilters (Value : integer); begin   if Value <> FFilters then   begin     FFilters := Value;     Update   end end; // Change the current sub-tree condition procedure TDiscMonitorThread.SetSubTree (Value : boolean); begin   if Value <> FSubTree then   begin     FSubtree := Value;     Update   end end; Function TDiscMonitor.GetChangeDelay : Integer;  {ie01} begin   Result := FMonitor.ChangeDelay; end; Procedure TDiscMonitor.SetChangeDelay(Value : Integer);  {ie01} begin   FMonitor.ChangeDelay := Value; end; // On any of the above three changes, if the thread is running then // signal it that a change has occurred. procedure TDiscMonitorThread.Update; begin   if not Suspended then     SetEvent (FChangeEvent) end; // The EXECUTE procedure //     ------- // Execute needs to: // 1. Call FindFirstChangeNotification and use the Handle in a WaitFor... //    to wait until the thread become signalled that a notification has occurred. //    The OnChange event is called and then the FindNextChangeNotification is //    the called and Execute loops back to the WaitFor // 2. If an invalid handle is obtained from the above call, the the OnInvalid //    event is called and then Execute waits until valid conditions are set. // 3. If a ChangeEvent is signalled then FindCloseChangeNotification is called, //    followed by a new FindFirstChangeNotification to use the altered //    conditions. // 4. If a DestroyEvent is signalled then FindCloseChangeNotification is //    called and the two events are closed and the thread terminates. // // In practice WaitForMultipleObjects is used to wait for any of the conditions // to be signalled, and the returned value used to determine which event occurred. procedure TDiscMonitorThread.Execute; // There appears to be a bug in win 95 where the bWatchSubTree parameter // of FindFirstChangeNotification which is a BOOL only accepts values of // 0 and 1 as valid, rather than 0 and any non-0 value as it should.  In D2 // BOOL was defined as 0..1 so the code worked, in D3 it is 0..-1 so // fails. The result is FindF... produces and error message.  This fix (bodge) is // needed to produce a 0,1 bool pair, rather that 0,-1 as declared in D3 const   R : array [false..true] of BOOL = (BOOL (0), BOOL (1)); var   A : array [0..2] of THandle; // used to give the handles to WaitFor...   B : boolean;                 // set to true when the thread is to terminate begin   B := false;   A [0] := FDestroyEvent;      // put DestroyEvent handle in slot 0   A [1] := FChangeEvent;       // put ChangeEvent handle in slot 1 // make the first call to the change notification system and put the returned // handle in slot 2.   A [2] := FindFirstChangeNotification (PChar(FDirectory), R[fSubTree], FFilters);   repeat // if the change notification handle is invalid then:     if A [2] = INVALID_HANDLE_VALUE then     begin   // call the OnInvalid event       Synchronize (InformInvalid);   // wait until either DestroyEvent or the ChangeEvents are signalled       case WaitForMultipleObjects (2, PWOHandleArray (@A), false, INFINITE) - WAIT_OBJECT_0 of   // DestroyEvent - close down by setting B to true         0 : B := true;   // try new conditions and loop back to the invalid handle test         1 : A [2] := FindFirstChangeNotification (PChar(FDirectory), R[fSubTree], FFilters)       end     end else // handle is valid so wait for any of the change notification, destroy or // change events to be signalled       case WaitForMultipleObjects (3, PWOHandleArray (@A), false, INFINITE) - WAIT_OBJECT_0 of         0 : begin   // DestroyEvent signalled so use FindClose... and close down by setting B to true               FindCloseChangeNotification (A [2]);               B := true             end;         1 : begin   // ChangeEvent signalled so close old conditions by FindClose... and start   // off new conditions.  Loop back to invalid test in case new conditions are   // invalid               FindCloseChangeNotification (A [2]);               A [2] := FindFirstChangeNotification (PChar(FDirectory), R[fSubTree], FFilters)             end;         2 : begin   // Notification signalled, so fire the OnChange event and then FindNext..   // loop back to re-WaitFor... the thread               Sleep(fChangeDelay);  {ie01 ins}               Synchronize (InformChange);               FindNextChangeNotification (A [2])             end;       end   until B Or Self.Terminated; // closing down so chuck the two events   CloseHandle (FChangeEvent);   CloseHandle (FDestroyEvent) end; //=== MONITOR COMPONENT ======================================================== // This component encapsulates the above thread.  It has properties for // directory, sub-directory conditions, filters, whether information messages // should be given at design time and if the thread is active. constructor TDiscMonitor.Create (AOwner : TComponent); begin   inherited Create (AOwner);   FMonitor := TDiscMonitorThread.Create;  // create a monitor thread   FMonitor.ChangeDelay := 500;            {ie01}   FMonitor.OnChange := Change;            // hook into its event handlers   FMonitor.OnInvalid := Invalid;   Filters := [moFilename];                // default filters to moFilename   SubTree := true                         // default sub-tree search to on end; destructor TDiscMonitor.Destroy; begin   FMonitor.Free;                          // chuck the thread   inherited Destroy end; // Change notification from the thread has occurred. Call the component's event // handler and then, if in design mode, and if desired, put up a simple // notification message procedure TDiscMonitor.Change; begin   if Assigned (FOnChange) then     FOnChange (Self)   else     if (csDesigning in ComponentState) and FShowMsg then       ShowMessage ('Change signalled') end; // Invalid notification from the thread has occurred. Call the component's event // handler and then, if in design mode, and if desired, put up a simple // notification message procedure TDiscMonitor.Invalid; begin   if Assigned (FOnInvalid) then     FOnInvalid (Self)   else     if (csDesigning in ComponentState) and FShowMsg then       ShowMessage ('Invalid parameter signalled') end; // Stop the monitor running procedure TDiscMonitor.Close; begin   Active := false end; // Run the monitor procedure TDiscMonitor.Open; begin   Active := true end; // Control the thread by using it's resume and suspend methods procedure TDiscMonitor.SetActive (Value : boolean); begin   if Value <> FActive then   begin     FActive := Value;     if Active then     begin       FMonitor.Resume;       FMonitor.Update     end else       FMonitor.Suspend   end end; // get the current directory from the thread function TDiscMonitor.GetDirectory : TDiscMonitorDirStr; begin   Result := FMonitor.Directory end; // get the current sub-tree status from the thread function TDiscMonitor.GetSubTree : boolean; begin   Result := FMonitor.SubTree end; // set the directory to monitor procedure TDiscMonitor.SetDirectory (Value : TDiscMonitorDirStr); begin   FMonitor.Directory := Value end; // Change the filter conditions.  The thread uses the raw windows constants // (FILE_NOTIFY_CHANGE_XXXX) but the components uses a set of enumurated type. // It is therefore necessary to translate from the component format into // an integer value for the thread. procedure TDiscMonitor.SetFilters (Value : TMonitorFilters); const   XlatFileNotify : array [moFilename..moSecurity] of integer =     (FILE_NOTIFY_CHANGE_FILE_NAME,  FILE_NOTIFY_CHANGE_DIR_NAME,      FILE_NOTIFY_CHANGE_ATTRIBUTES, FILE_NOTIFY_CHANGE_SIZE,      FILE_NOTIFY_CHANGE_LAST_WRITE, FILE_NOTIFY_CHANGE_SECURITY); var   L : TMonitorFilter;   I : integer; begin   if Value <> FFilters then     if Value = [] then       ShowMessage ('Some filter condition must be set.')     else begin       FFilters := Value;       I := 0;       for L := moFilename to moSecurity do         if L in Value then           I := I or XlatFileNotify [L];       FMonitor.Filters := I;     end end; // set the sub-tree status in the thread procedure TDiscMonitor.SetSubTree (Value : boolean); begin   FMonitor.SubTree := Value end; procedure Register; begin   RegisterComponents ('FileSys', [TDiscMonitor]);   {RegisterPropertyEditor (TypeInfo (TDiscMonitorDirStr), nil, '', TDiscMonitorDirStrProperty);} end; end. 另外如果是在NT下面,调用得函数是CreateIOCompletionPort 而不是CreateCompletionPort,上次说错了.

用ReadDirectoryChangesW与上面得方法相似. 这是一个外国人的代码.

张磊 · 1999-10-14

还没有结束吗? 嘻嘻,给分把.

3h · 1999-10-16

分我一定会给，不用担心。 只是这些天在搞工作单位的事，所以没空玩请原谅。 等过些天我会检查这个程序和问题并给分的。

3h · 1999-11-16

tring.........

3h · 2000-01-16

张先生的那个控件很好用，我很喜欢。 接受答案了，让诸位久等！ 分数每人至少5分，安慰安慰。

一个关于 Windows Message 的问题 from 3h(300分)

3h

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cmxu

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delphiwolf

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张磊

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张磊

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3h

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