SerialPort.GetPortNames（）行为 [英] SerialPort.GetPortNames() behavior

问题描述

在我的C＃2008应用程序中，我使用了SerialPort.GetPortNames（）函数来检索当前可用端口列表。我所注意到的是，当过我插入USB设备，它的端口号显示在列表上的我的应用程序，当我拔掉它，并刷新列表，端口号就不再出现了。

In my C# 2008 application, I use the SerialPort.GetPortNames() function to retrieve the list of currently available ports. What I have noticed is, when ever I plug in a USB device, it's port number i s shown in the list on my Application and when I unplug it and refresh the list, the port number is no longer there.

本申请的一个阶段从/向连续的设备包括读/写数据。现在，我的期望是，如果我在操作过程中拔出设备，并使用SerialPort.GetPortNames（），端口名称不会在那里得到当前的端口列表，我可以用它来使该设备已被拔出的决定。

One phase of the application involves reading/writing data from/to the device continuously. Now, my expectation is, If I unplug the device during the operation and get the current Port list using SerialPort.GetPortNames(), the Port Name will not be there and I can use that to make the decision that the device has been unplugged.

让我惊讶的是，端口名称仍然发现，尽管有它删除

为什么程序的行为也是这样吗？端口名称没有在非通信模式时列出。它有什么做的设备时，它的通信被删除？

Why is the program behaving like this? The port name isn't listed when in no-communication mode. Does it have something to do with the device being removed when it's communicating?

推荐答案

我假设你的意思是System.IO。 Ports.SerialPort.GetPortNames（），因为我找不到任何地方一个GetPortList（）函数。 MSDN说：如果注册表中包含过时或不正确的数据则GetPortNames方法将返回不正确的数据，所以这可能是问题所在。我想，如果仍然被拿来主义的端口，就像你无法删除文件时，程序上有一个手柄Windows不更新注册表。

I'm assuming you mean System.IO.Ports.SerialPort.GetPortNames(), because i could not find a GetPortList() function anywhere. MSDN says: "If the registry contains stale or otherwise incorrect data then the GetPortNames method will return incorrect data", so that's probably where the problem lies. I guess Windows doesn't update the registry if the port is still being 'used', just like you can't delete a file when a program has a handle on it.

如果你想测试设备是否被删除，你可以用一个窗口API调用（http://www.pinvoke.net/default.aspx/user32/RegisterDeviceNotification.html）这样做。希望帮助！

If you want to test if the device is removed, you can do so with a Window API call (http://www.pinvoke.net/default.aspx/user32/RegisterDeviceNotification.html). Hope that helps!

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