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我在单独的线程应用程序配置文件中进行监控，在某些情况下，它可能是另一个 XML 或另一个 XML 中的 INI。线程监控目录的代码（在Delphi中）是这样的：

procedure TWatcherThread.Execute;
type
  PFileNotifyInformation = ^TFileNotifyInformation;
  TFileNotifyInformation = record
    NextEntryOffset: DWORD;
    Action: DWORD;
    FileNameLength: DWORD;
    FileName: WideChar;
  end;
const
  BufferLength = 65536;
var
  Filter, BytesRead: DWORD;
  InfoPointer: PFileNotifyInformation;
  Offset, NextOffset: DWORD;
  Buffer: array[0..BufferLength - 1] of byte;
  Overlap: TOverlapped;
  Events: array[0..1] of THandle;
  WaitResult: DWORD;
  FileName, s: string;
begin
  if fDirHandle <> INVALID_HANDLE_VALUE then begin
    Filter := FILE_NOTIFY_CHANGE_LAST_WRITE;

    FillChar(Overlap, SizeOf(TOverlapped), 0);
    Overlap.hEvent := fChangeHandle;

    Events[0] := fChangeHandle;
    Events[1] := fShutdownHandle;

    while not Terminated do begin
      FillChar(Buffer,SizeOf(Buffer),0);
      if ReadDirectoryChangesW (fDirHandle, @Buffer[0], BufferLength, TRUE,
        Filter, @BytesRead, @Overlap, nil)
      then begin
        WaitResult := WaitForMultipleObjects(2, @Events[0], FALSE, INFINITE);
        if WaitResult = WAIT_OBJECT_0 then begin
          InfoPointer := @Buffer[0];
          Offset := 0;
          repeat
            NextOffset := InfoPointer.NextEntryOffset;
            FileName := WideCharToString(@InfoPointer.FileName);

            if (InfoPointer.Action = FILE_ACTION_MODIFIED) and (CompareText(FileName, 'MyConfig.ini') = 0) then begin //read changes in config or INI file
              // Do Action.. refresh runtime flags
            end;
            PByte(InfoPointer) := PByte(DWORD(InfoPointer) + NextOffset);
            Offset := Offset + NextOffset;
          until NextOffset = 0;
        end;
      end;
    end;
  end;
end;

为什么它至少发出 2 次信号以及当配置文件中的某些标志被更改并保存时如何获得正确的信号？

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1 回答 1

2

Raymond Chen 在他的博客上很好地解释了这一点：http: //blogs.msdn.com/b/oldnewthing/archive/2014/05/07/10523172.aspx

简而言之，“因为修改了多项内容。”

于 2014-06-25T07:59:44.363 回答