fmShareDenyWrite 模式似乎不起作用

发布于 2024-09-06 20:58:30 字数 491 浏览 5 评论 0原文

我正在使用 TFileSteam 打开日志文件。我希望能够从其他进程读取此日志文件。我认为 fmShareDenyWrite 模式允许这样做。

但是，如果我尝试从其他进程打开该文件，则会收到错误。例如，如果我尝试从命令行键入文件，我会得到“该进程无法访问该文件，因为它正在被另一个进程使用”。

这是文件初始化代码：

if FileExists(AutoLogFileName) then
   _ActivityLogStream := TFileStream.Create(AutoLogFileName, 
          fmOpenReadWrite or fmShareDenyWrite)
else
   _ActivityLogStream := TFileStream.Create(AutoLogFileName, 
          fmCreate or fmShareDenyWrite);

注意：我使用的是 Delphi 版本 6。

原文

I'm using a TFileSteam to open a log file. I would like to be able to read through this log file from other processes. I thought the fmShareDenyWrite mode would allow this.

However if I try to open the file from other processes, I get an error. For example, if I try and type the file from the command line, I get "the process can not access the file because it is being used by another process".

Here is the file initialization code:

if FileExists(AutoLogFileName) then
   _ActivityLogStream := TFileStream.Create(AutoLogFileName, 
          fmOpenReadWrite or fmShareDenyWrite)
else
   _ActivityLogStream := TFileStream.Create(AutoLogFileName, 
          fmCreate or fmShareDenyWrite);

NOTE:
I am using Delphi version 6.

分享到QQ

分享到微博

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

发布评论

需要登录才能够评论，你可以免费注册一个本站的账号。

源来凯始玺欢你 2024-09-13 20:58:30

不知道这是否已经是 D6 中的一个错误，但这是一个明显的可能性。有一份针对 D2007 的 QC 报告：QC 65767：http://qc .embarcadero.com/wc/qcmain.aspx?d=65767。该报告现已关闭，因为它已在 D2010 中得到解决（确切地说是 14.0.3467.22472）。

更新（由 Gabr 的评论提示）：

您可以创建自己的 TFileStream 后代，该后代确实遵循该模式。只需重写 Create(const AFileName: string; Mode: Word; Rights: Cardinal) 构造函数（有两个重载构造函数）并自行处理模式参数即可。复制原始构造函数中的代码，并将更改为

  if Mode = fmCreate then
  begin
    inherited Create(FileCreate(AFileName, Rights));

其中

  if (Mode and fmCreate = fmCreate) then
  begin
    myMode := Mode and $FF;
    if myMode = $FF then
      myMode := fmShareExclusive;
    inherited Create(FileCreate(AFileName, myMode, Rights));

myMode 是 Word 类型的本地变量。

Don't know whether this was already a bug in D6, but that is a distinct possibility. There is a QC report on this reported against D2007: QC 65767: http://qc.embarcadero.com/wc/qcmain.aspx?d=65767. This report is now closed, as it was resolved in D2010 (14.0.3467.22472 to be exact).

Update (prompted by Gabr's comment):

You can create your own TFileStream descendant that does honor the mode. Just override the Create(const AFileName: string; Mode: Word; Rights: Cardinal) constructor (there are two overloaded constructors) and handle the mode parameter yourself. Copy the code from the original constructor and change the

  if Mode = fmCreate then
  begin
    inherited Create(FileCreate(AFileName, Rights));

  if (Mode and fmCreate = fmCreate) then
  begin
    myMode := Mode and $FF;
    if myMode = $FF then
      myMode := fmShareExclusive;
    inherited Create(FileCreate(AFileName, myMode, Rights));

where myMode is a local var of type Word.

回复收藏 0 原文