API刷新目录

Question

刷新桌面可以用 SHChangeNotify(SHCNE_ASSOCCHANGED, SHCNF_IDLIST, nil, nil);那么刷新特定目录呢我要的是在目录内点击刷新的效果

Answer 1

试试SHChangeNotify(SHCNE_UPDATEDIR,   SHCNF_IDLIST,   nil,   nil);

Answer 2

 SHChangeNotify(SHCNE_UPDATEDIR,
                 SHCNF_PATH or SHCNF_IDLIST,
                 PChar('C:\Dir'),
                 NiL);
看这样行不 

Answer 3

to sailxia
 
你有什么好的方案to gyk120 模拟按键恐怕是不行的，因为日志目录并不打开

Answer 4

to sailxia
 
如果按照你3楼说的，刷新目录这样做并不是一个好方法，你应该监视那个日志文件。我就是监控此文件改变才读取的，问题是有时候写入日志文件并不会改变，需要刷新下目录才会改变我是监控另一款程序的日志文件，所以对日志的输出处理是没有办法的我也尝试过用管道，但是却不能输出任何信息，利用DOS命令重定向到其他文件 也是不能输出任何信息没办法只能监控日志文件了，但是日志文件有时候必须手动刷新下才会更新。。所以我才问如何实现WINDOWS的右键刷新功能

Answer 5

根据你的需求，可以用ReadDirectoryChanges

Answer 6

ReadDirectoryChanges同样不行此段代码就是用ReadDirectoryChanges监控目录的同样不能监控到文件更改，必须刷新后才会监控到

Answer 7

unit Unit1;interfaceuses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls, ExtCtrls, Buttons;type
  TForm1 = class(TForm)
    lbEvents: TListBox;
    Label1: TLabel;
    ePath: TEdit;
    CJLabel1: TLabel;
    bStart: TButton;
    bStop: TButton;
    ckWatchSubTree: TCheckBox;
    ckMonitorFileName: TCheckBox;
    ckMonitorDirName: TCheckBox;
    ckMonitorAttributes: TCheckBox;
    ckMonitorSize: TCheckBox;
    ckMonitorLastWrite: TCheckBox;
    ckMonitorSecurity: TCheckBox;
    ckMonitorCreationDate: TCheckBox;
    ckMonitorLastAccess: TCheckBox;
    SpeedButton1: TSpeedButton;
    procedure bStartClick(Sender: TObject);
    procedure bStopClick(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure ePathDblClick(Sender: TObject);
  private
    FDirectoryHandle: THandle;
    FNotificationBuffer: array[0..4096] of Byte;
    FWatchThread: TThread;
    FNotifyFilter: DWORD;
    FOverlapped: TOverlapped;
    FPOverlapped: POverlapped;
    FBytesWritten: DWORD;
    FCompletionPort: THandle;
  public
  end;var
  Form1: TForm1;type
  PFileNotifyInformation = ^TFileNotifyInformation;
  TFileNotifyInformation = record
    NextEntryOffset: DWORD;
    Action: DWORD;
    FileNameLength: DWORD;
    FileName: array[0..0] of WideChar;
  end;const
  FILE_LIST_DIRECTORY   = $0001;const
  SAction: array[FILE_ACTION_ADDED..FILE_ACTION_RENAMED_NEW_NAME] of String =
  ( '增加-> %s',
    '删除-> %s',
    '访问-> %s',
    '改名-> %s [...]',
    '[...] 改为 %s');implementation{$R *.DFM}uses
  ShlObj, ActiveX;type
  TWaitThread = class(TThread)
  private
    FForm: TForm1;
    procedure HandleEvent;
  protected
    procedure Execute; override;
  public
    constructor Create(Form: TForm1);
  end;constructor TWaitThread.Create(Form: TForm1);
begin
  inherited Create(True);
  FForm := Form;
  FreeOnTerminate := False;
end;procedure TWaitThread.HandleEvent;
var
  FileOpNotification: PFileNotifyInformation;
  Offset: Longint;
  s:Array[1..127] of char; i:DWord;
begin
  Getcomputername(@s,i);
  with FForm do
  begin
    Pointer(FileOpNotification) := @FNotificationBuffer[0];
    repeat
      Offset := FileOpNotification^.NextEntryOffset;
      lbEvents.Items.Add(Format(SAction[FileOpNotification^.Action], [WideCharToString(@(FileOpNotification^.FileName))])+s);
      PChar(FileOpNotification) := PChar(FileOpNotification)+Offset;
    until Offset=0;
  end;
end;procedure TWaitThread.Execute;
var
  numBytes: DWORD;
  cbOffset: DWORD;
  CompletionKey: DWORD;
begin
  while not Terminated do
  begin
    GetQueuedCompletionStatus( FForm.FCompletionPort, numBytes, CompletionKey, FForm.FPOverlapped, INFINITE);
    if CompletionKey <> 0 then
    begin
      Synchronize(HandleEvent);
      with FForm do
      begin
        FBytesWritten := 0;
        ZeroMemory(@FNotificationBuffer, SizeOf(FNotificationBuffer));
        ReadDirectoryChanges(FDirectoryHandle, @FNotificationBuffer, SizeOf(FNotificationBuffer), ckWatchSubTree.Checked, FNotifyFilter, @FBytesWritten, @FOverlapped, nil);
      end;
    end
    else
      Terminate;
  end;
end;procedure TForm1.bStartClick(Sender: TObject);
begin
  FNotifyFilter := 0;
  if ckMonitorFileName.Checked then
    FNotifyFilter := FNotifyFilter or FILE_NOTIFY_CHANGE_FILE_NAME;
  if ckMonitorDirName.Checked then
    FNotifyFilter := FNotifyFilter or FILE_NOTIFY_CHANGE_DIR_NAME;
  if ckMonitorAttributes.Checked then
    FNotifyFilter := FNotifyFilter or FILE_NOTIFY_CHANGE_ATTRIBUTES;
  if ckMonitorSize.Checked then
    FNotifyFilter := FNotifyFilter or FILE_NOTIFY_CHANGE_SIZE;
  if ckMonitorLastWrite.Checked then
    FNotifyFilter := FNotifyFilter or FILE_NOTIFY_CHANGE_LAST_WRITE;
  if ckMonitorLastAccess.Checked then
    FNotifyFilter := FNotifyFilter or FILE_NOTIFY_CHANGE_LAST_ACCESS;
  if ckMonitorCreationDate.Checked then
    FNotifyFilter := FNotifyFilter or FILE_NOTIFY_CHANGE_CREATION;
  if ckMonitorSecurity.Checked then
    FNotifyFilter := FNotifyFilter or FILE_NOTIFY_CHANGE_SECURITY;
  if FNotifyFilter = 0 then
  begin
     ShowMessage(请选择监视内容!');
     exit;
  end;
  lbEvents.Clear;
  FDirectoryHandle := CreateFile(PChar(ePath.Text),
    FILE_LIST_DIRECTORY,
    FILE_SHARE_READ or FILE_SHARE_WRITE or FILE_SHARE_DELETE,
    nil,
    OPEN_EXISTING,
    FILE_FLAG_BACKUP_SEMANTICS or FILE_FLAG_OVERLAPPED,
    0);
  if FDirectoryHandle = INVALID_HANDLE_VALUE then
  begin
    beep;
    FDirectoryHandle := 0;
    ShowMessage(SysErrorMessage(GetLastError));
    exit;
  end;
  FCompletionPort := CreateIoCompletionPort(FDirectoryHandle, 0, Longint(pointer(self)), 0);
  ZeroMemory(@FNotificationBuffer, SizeOf(FNotificationBuffer));
  FBytesWritten := 0;
  if not ReadDirectoryChanges(FDirectoryHandle, @FNotificationBuffer, SizeOf(FNotificationBuffer), ckWatchSubTree.Checked, FNotifyFilter, @FBytesWritten, @FOverlapped, nil) then
  begin
    CloseHandle(FDirectoryHandle);
    FDirectoryHandle := 0;
    CloseHandle(FCompletionPort);
    FCompletionPort := 0;
    ShowMessage(SysErrorMessage(GetLastError));
    exit;
  end;
  ePath.Enabled := False;
  bStart.Enabled := False;
  bStop.Enabled := True;
  FWatchThread := TWaitThread.Create(self);
  TWaitThread(FWatchThread).Resume;
end;procedure TForm1.bStopClick(Sender: TObject);
begin
  if FCompletionPort = 0 then
    exit;
  PostQueuedCompletionStatus(FCompletionPort, 0, 0, nil);
  FWatchThread.WaitFor;
  FWatchThread.Free;
  CloseHandle(FDirectoryHandle);
  FDirectoryHandle := 0;
  CloseHandle(FCompletionPort);
  FCompletionPort := 0;
  ePath.Enabled := True;
  bStart.Enabled := True;
  bStop.Enabled := False;
end;procedure TForm1.FormDestroy(Sender: TObject);
begin
  bStop.Click;
end;procedure TForm1.FormCreate(Sender: TObject);
begin
  FCompletionPort := 0;
  FDirectoryHandle := 0;
  FPOverlapped := @FOverlapped;
  ZeroMemory(@FOverlapped, SizeOf(FOverlapped));
end;procedure TForm1.ePathDblClick(Sender: TObject);
var
  SelectionPIDL: PItemIDList;
  BrowseInfo: TBrowseInfo;
  ShellAllocator: IMalloc;
  PathBuffer: array[0..MAX_PATH] of Char;
begin
  // simplest implementation of BrowseForFolder
  excellent site www.delphifreestuff.com
  ZeroMemory(@BrowseInfo, SizeOf(BrowseInfo));
  BrowseInfo.hwndOwner := Handle;
  BrowseInfo.ulFlags := BIF_RETURNONLYFSDIRS;
  CoInitialize(nil);
  try
    SelectionPIDL := ShBrowseForFolder(BrowseInfo);
    if SelectionPIDL <> nil then
    try
      ZeroMemory(@PathBuffer, SizeOf(PathBuffer));
      if not SHGetPathFromIDList(SelectionPIDL, @PathBuffer) then
      begin
        beep;
        exit;
      end;
      ePath.Text := StrPas(@PathBuffer[0]);
    finally
      if SHGetMalloc(ShellAllocator) = 0 then
      begin
        ShellAllocator.Free(SelectionPIDL);
        ShellAllocator := nil;
      end;
    end;
  finally
    CoUnInitialize;
  end;
end;end.

Answer 8

安装个 CNVCL，里面的文件监控，有例子，很好用。