delphi 判断文件是否被占用

class function TWmsApplicationfunction.IsFileInUse(FileName: TFileName): Boolean;
var
HFileRes: HFILE;
begin
Result := False;
if not FileExists(FileName) then
Exit;    // 如果文件不存在，返回false
HFileRes := CreateFile(PChar(FileName), GENERIC_READ or GENERIC_WRITE, 0, nil, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
Result := (HFileRes = INVALID_HANDLE_VALUE);
if not Result then
CloseHandle(HFileRes);
end;