Win32的确定连接键盘时/断开

问题描述

我试图确定什么时候我的键盘连接或断开。我曾尝试以下策略：

RegisterDeviceNotification

使用RegisterDeviceNotifaction作为的建议在how确定键盘的DirectInput 断开。当我尝试这样做，我得到 DB_DEVNODES_CHANGED 事件窗口中的回调提供任何其他信息（只是一些未知的设备改变连接状态）。我尝试过各种的GUID进行注册： 4D36E96B-E325-11CE-BFC1-08002BE10318 （一些网站说，这是GUID的键盘类）和检索的guidInstance IDirectInput8 :: EnumDevices（DI8DEVCLASS_KEYBOARD，...，DIEDFL_ATTACHEDONLY）。但我仍然只得到了 DB_DEVNODES_CHANGED 事件。

IDirectInput8 :: EnumDevices

每个调用 IDirectInput8 :: EnumDevices（DI8DEVCLASS_KEYBOARD，...，DIEDFL_ATTACHEDONLY）只列举了所连接的设备。然而，当我断开我的键盘，它仍然得到由 EnumDevices 枚举。当我做同样为我的游戏控制器（带类型 DI8DEVCLASS_GAMECTRL ）的控制器，只有当它连接列举，让我确定它的连接状态。

其他功能

我曾尝试：

1. IDirectInput8 :: GetDeviceStatus


2. IDirectInputDevice8 ::获得性能


3. IDirectInputDevice8 :: GetDeviceInfo


4. IDirectInputDevice8 :: GetDeviceState


5. IDirectInputDevice8 ::投票

所有功能成功，并提供没有洞察到，如果键盘连接。

我也通过MSDN的的，都无济于事。

问题

1. 谁能谁做了这个成功的确认，我采取正确的方法呢？


2. 有没有我可以俯瞰其他功能或API？


3. 是举一个例子任何网站（我已经失败一派）？


4. 为什么 EnumDevices 正常工作对我的控制器，但不是我的键盘？而如何让我为我的键盘工作？

解决方案

你有没有考虑 GetRawInputDeviceList（）和 GetRawInputDeviceInfo（），使用RID_DEVICE_INFO为pData所和检查它的dwType？

这将让你的初始状态，这时如果你的WndProc处理WM_INPUT_DEVICE_CHANGE可以使用PARAMS检测到添加/删除，和lParam的可以发送straigth到 GetRawInputDeviceInfo（）。

每注释：本WM_INPUT_DEVICE_CHANGE将只为呼吁应用到 RegisterRawInputDevices（），并特别要求此通知

I am trying to determine when my keyboard is connected or disconnected. I have tried the following strategies:

RegisterDeviceNotification

Using RegisterDeviceNotifaction as explained on MSDN was suggested in how to determine keyboard disconnected in DirectInput. When I tried this I get DB_DEVNODES_CHANGED event in the window callback which provides no other information (just some unknown device has changed connection state). I tried various GUIDs for the registration: 4D36E96B-E325-11CE-BFC1-08002BE10318 (several websites said this is the class guid for keyboards) and the guidInstance retrieved from IDirectInput8::EnumDevices(DI8DEVCLASS_KEYBOARD, ..., DIEDFL_ATTACHEDONLY). But I still only get the DB_DEVNODES_CHANGED event.

IDirectInput8::EnumDevices

Each call to IDirectInput8::EnumDevices(DI8DEVCLASS_KEYBOARD, ..., DIEDFL_ATTACHEDONLY) should only enumerate the devices that are attached. However, when I disconnect my keyboard, it still gets enumerated by EnumDevices. When I do the same for my game controller (with the type DI8DEVCLASS_GAMECTRL) the controller is only enumerated when it is attached, allowing me to determine its connection state.

Other Functions

I have tried:

1. IDirectInput8::GetDeviceStatus
2. IDirectInputDevice8::GetCapabilities
3. IDirectInputDevice8::GetDeviceInfo
4. IDirectInputDevice8::GetDeviceState
5. IDirectInputDevice8::Poll

All functions succeed and provide no insight into if the keyboard is connected.

I have also looked through MSDN's keyboard section, to no avail.

Questions

1. Can anyone who has done this successfully confirm I'm taking the right approach?
2. Is there another function or API I am overlooking?
3. Any websites that give an example (I've googled unsuccessfully)?
4. Why does EnumDevices work correctly for my controller but not my keyboard? And how do I make it work for my keyboard?

解决方案

Have you considered GetRawInputDeviceList() and GetRawInputDeviceInfo(), using RID_DEVICE_INFO for pData and checking it's dwType?

That will get you the initial state, then if your wndProc handles WM_INPUT_DEVICE_CHANGE you can use the params to detect add/remove, and the lParam can be sent straigth to GetRawInputDeviceInfo().

Per comments: The WM_INPUT_DEVICE_CHANGE will only arrive for apps that have called RegisterRawInputDevices() and specifically asked for this notification.

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