如何使用 C# 检测不存在的设备
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【中文标题】如何使用 C# 检测不存在的设备【英文标题】:How to detect nonpresent devices using C# 【发布时间】:2014-12-17 03:07:53 【问题描述】:我的程序(完全用 C# 编写)有一个用例,程序需要检测计算机中是否安装了特定的 USB 设备。在连接了 USB 设备的情况下,WMI 将解决这个问题。
但是,如果设备未连接(不存在的设备),那么 WMI 将无法提供帮助。我知道 setupdi 可能会帮助解决这个问题,但是我对 C++ 并不完全熟悉,并且由于符合现有代码部分,因此添加编组函数的额外工作非常重要。
因此我的问题是是否有等效的 c# 方法来检测系统中不存在的设备?我也试过注册表搜索的方法,但是驱动是HKLM\System\CurrentControlSet\services\WinUSB下的通用USB驱动,并没有额外的信息可以用来识别USB驱动对应具体的设备我们感兴趣。
另一个可能的识别信息是设备管理器中驱动程序选项卡中的“驱动程序提供程序”信息。 usb 设备有相当具体的驱动程序提供者信息,可用于识别设备。但是我不知道现有的 API 来检索这些信息。
非常感谢您的帮助并期待任何可能的解决方案
【问题讨论】:
【参考方案1】:不知道这是否有帮助。这是我大约 7 年前写的一些 sn-ps 代码,从那以后就没有使用过 - 该项目被放弃了。不幸的是,整个 USB 接口大约有 700 行 C# - 太多了,无法在此处发布。
/// <summary>
/// This class represents a USB HID (Human Interface Device) device.
/// </summary>
public class UsbHidDevice : IDisposable
// The Windows GUID for HID USB devices
private Guid _deviceClass;
// The full "path name" of the device (set when found)
private string _devicePath;
#region Constructor
public UsbHidDevice()
// Initialize the Windows GUID for HID devices
Win32API.HidD_GetHidGuid(out _deviceClass);
#endregion Constructor
/// <summary>
/// Function to search the USB devices to see if the desired one is online.
/// </summary>
/// <param name="vendorId">vendor ID, or zero if not significant</param>
/// <param name="productId">product ID</param>
public bool FindDevice(int vendorId, int productId)
string strSearch;
// Build the path search string
if (vendorId == 0)
strSearch = string.Format("pid_0:x4", productId);
else
strSearch = string.Format("vid_0:x4&pid_1:x4", vendorId, productId);
// Prepare to search the USB device table in Windows
// This gets a list of all HID devices currently connected to the computer (InfoSet)
IntPtr hInfoSet = Win32API.SetupDiGetClassDevs(ref _deviceClass, null, IntPtr.Zero, Win32API.DIGCF_DEVICEINTERFACE | Win32API.DIGCF_PRESENT);
try
// Build up a device interface data block
Win32API.DeviceInterfaceData oInterface = new Win32API.DeviceInterfaceData();
oInterface.Size = Marshal.SizeOf(oInterface);
// Now iterate through the InfoSet memory block assigned within Windows in the
// call to SetupDiGetClassDevs to get device details for each device connected
int nIndex = 0;
// This gets the device interface information for a device at index 'nIndex' in the memory block
while (Win32API.SetupDiEnumDeviceInterfaces(hInfoSet, 0, ref _deviceClass, (uint)nIndex, ref oInterface))
// Get the device path (see helper method 'GetDevicePath')
string strDevicePath = GetDevicePath(hInfoSet, ref oInterface);
// Do a string search, if we find the VID/PID string then we found our device
if (!string.IsNullOrEmpty(strDevicePath) && strDevicePath.IndexOf(strSearch) >= 0)
_devicePath = strDevicePath;
return true;
// If we get here, we didn't find our device. So move on to the next one.
log.Debug("FindDevice() - Incorrect device found, keep searching." + strDevicePath);
nIndex++;
catch (Exception e)
log.Error("FindDevice() - Exception:", e);
finally
// Before we go, we have to free up the InfoSet memory reserved by SetupDiGetClassDevs
Win32API.SetupDiDestroyDeviceInfoList(hInfoSet);
// Device not found
return false;
... other methods not included here
/// <summary>
/// Definition of some Windows API stuff.
///
/// This is copied from "A USB HID Component for C#" (also called "Sniffer"), By "wimar"
/// http://www.codeproject.com/KB/cs/USB_HID.aspx
/// </summary>
internal class Win32API
// Used in SetupDiClassDevs to get devices present in the system
public const int DIGCF_PRESENT = 0x02;
// Used in SetupDiClassDevs to get device interface details
public const int DIGCF_DEVICEINTERFACE = 0x10;
/// <summary>
/// Provides details about a single USB device
///
/// The field "Reserved" has been changed from int to UIntPtr based on information on web page
/// http://www.codeproject.com/KB/cs/USB_HID.aspx, see message "Does not work on 64 bit Vista?".
/// </summary>
[StructLayout(LayoutKind.Sequential, Pack = 1)]
public struct DeviceInterfaceData
public int Size;
public Guid InterfaceClassGuid;
public int Flags;
public UIntPtr Reserved;
/// <summary>
/// Gets the GUID that Windows uses to represent HID class devices
/// </summary>
/// <param name="gHid">An out parameter to take the Guid</param>
[DllImport("hid.dll", SetLastError = true)]
public static extern void HidD_GetHidGuid(out Guid gHid);
/// <summary>
/// Allocates an InfoSet memory block within Windows that contains details of devices.
/// </summary>
/// <param name="gClass">Class guid (e.g. HID guid)</param>
/// <param name="strEnumerator">Not used</param>
/// <param name="hParent">Not used</param>
/// <param name="nFlags">Type of device details required (DIGCF_ constants)</param>
/// <returns>A reference to the InfoSet</returns>
[DllImport("setupapi.dll", SetLastError = true)]
public static extern IntPtr SetupDiGetClassDevs(ref Guid gClass, [MarshalAs(UnmanagedType.LPStr)] string strEnumerator, IntPtr hParent, uint nFlags);
/// <summary>
/// Gets the DeviceInterfaceData for a device from an InfoSet.
/// </summary>
/// <param name="lpDeviceInfoSet">InfoSet to access</param>
/// <param name="nDeviceInfoData">Not used</param>
/// <param name="gClass">Device class guid</param>
/// <param name="nIndex">Index into InfoSet for device</param>
/// <param name="oInterfaceData">DeviceInterfaceData to fill with data</param>
/// <returns>True if successful, false if not (e.g. when index is passed end of InfoSet)</returns>
[DllImport("setupapi.dll", SetLastError = true)]
public static extern bool SetupDiEnumDeviceInterfaces(IntPtr lpDeviceInfoSet, uint nDeviceInfoData, ref Guid gClass, uint nIndex, ref DeviceInterfaceData oInterfaceData);
/// <summary>
/// Frees InfoSet allocated in call to above.
/// </summary>
/// <param name="lpInfoSet">Reference to InfoSet</param>
/// <returns>true if successful</returns>
[DllImport("setupapi.dll", SetLastError = true)]
public static extern int SetupDiDestroyDeviceInfoList(IntPtr lpInfoSet);
... other stuff missing
正如代码中的注释中提到的,这是基于此:http://www.codeproject.com/Articles/18099/A-USB-HID-Component-for-C
我可能遗漏了一些需要的东西 - 请告诉我。
【讨论】:
感谢您的反馈,我已经使用 Win32API 实现了类似的东西。谢谢!【参考方案2】: string ComputerName = "localhost";
ManagementScope Scope;
Scope = new ManagementScope(String.Format("\\\\0\\root\\CIMV2", ComputerName), null);
Scope.Connect();
string query = "SELECT * FROM Win32_PnPEntity Where ClassGuid = NULL";
ObjectQuery Query = new ObjectQuery(query);
ManagementObjectSearcher Searcher = new ManagementObjectSearcher(Scope, Query);
foreach (ManagementObject WmiObject in Searcher.Get())
textBox1.Text += WmiObject["Name"] + "\r\n";
【讨论】:
不要只在答案中发布代码。试着向提问者解释一下 特别是当 OP 声明“那么 WMI 将无法提供帮助”时。既然您的代码只是一个 WMI 查询,请解释为什么它会违背 OP 的期望。 感谢您提供可能有助于解决问题的代码,但一般来说,如果答案包含对代码的用途以及解决问题的原因的解释,则会更有帮助。跨度>以上是关于如何使用 C# 检测不存在的设备的主要内容,如果未能解决你的问题,请参考以下文章