VB.Net 3.5检查文件是否正在使用 [英] VB.Net 3.5 Check if file is in use

问题描述

我有一个完全独立于我的主应用程序的更新程序。我运行update.exe来更新app.exe。要检查文件是否正在使用中，我将其移至另一个文件并在使用中捕获错误。如果没有问题，我将其重命名。至少那是我的计划...

I have an update program that is completely independent of my main application. I run the update.exe to update the app.exe. To check to see if the file is in use, I move it to another file and catch an error if it is in use. If no problems occurr I rename it back. At least that was my plan...

主程序：app.exe

更新程序：更新。 exe

Main program: app.exe
Update program: update.exe

该程序在网络上使用，没有任何服务在运行。因此，用户实际上是在他们的计算机上通过网络运行exe。

This program is used over the network without any services running. So, the users is quite literally running the exe over the network on thier machine.

当update.exe运行时，我需要更新app.exe。要检查app.exe是否仍在使用中，我将以下内容包装在try / catch中，以查看是否失败：

I need to update the app.exe when the update.exe has run. To check to see if the app.exe was still in use I was wrapping the following in a try/catch to see if it failed:

IO.File.Move（upddir& \app.exe，upddir& \app.exe.tst）

IO.File.Move（upddir& ＼ ＼app.exe.tst，upddir和 \app.exe）

IO.File.Move(upddir & "\app.exe", upddir & "\app.exe.tst")
IO.File.Move(upddir & "\app.exe.tst", upddir & "\app.exe")

有趣的是，即使app.exe正在运行，移动可以将其重命名为app.exe.tst，而不会发生任何错误。我什至可以继续进行应用程序而不会出现任何错误。

The funny thing is, even if the app.exe is running, the move can rename it to the app.exe.tst without any error. I can even continue on in the application without any errors.

我以为我不介意，所以我让另一个程序员看了一下，他证实了我上面说的话。

I thought I was out of my mind, so I had another programmer look at this and he verified what I said above.

因此，我们尝试将其包装在try catch中：

So, we tried this wrapped in a try catch:

将readfile设置为New FileStream（upddir& \ app.exe，FileMode.Open，FileAccess.Read，FileShare.None）。

readfile.Dispose（）

Dim readfile As New FileStream(upddir & "\app.exe", FileMode.Open, FileAccess.Read, FileShare.None)
readfile.Dispose()

我把文件共享设置为否，至少我认为这表明文件中有人。

I put the fileshare as none that, at least I thought it would, show that there was someone in the file.

它仍然继续运行，没有任何错误。

It still continued without any error.

谁知道为什么我可以重命名正在使用的文件？
另外，有没有比我现在做的更好的方法了？

Anyone know why I can rename a file in use? Also, is there a better way to do this than what I am doing now?

谢谢！
Eroc

Thanks! Eroc

推荐答案

您可以执行以下操作来检查应用程序是否正在运行其他实例：

You could do the following to check if the application has other instances running:

Process.GetProcessesByName("app.exe", "Machine1").Length > 0

检查应用程序是否运行的更合适的方法。

Which is a more appropriate way of checking if the app is running.

看看 File.Move MSDN文档。它详细说明了抛出什么异常。即使在Vista中使用了exe，也可以重命名它。

Have a look at File.Move MSDN documentation. It details what exceptions are thrown. You are allowed to rename an exe even if it is in Use in Vista.

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