我想知道在系统中添加或删除设备时是否有办法触发事件。我希望能够检测是否添加了 USB 闪存驱动器、鼠标或其他任何东西。我尝试四处搜索，但找不到任何说明如何执行此操作的内容。
有任何想法吗？
问问题
44381 次
6 回答
72
如果您的应用程序中有一个窗口，则可以使用以下内容：
using System;
using System.Runtime.InteropServices;
internal static class UsbNotification
{
public const int DbtDevicearrival = 0x8000; // system detected a new device
public const int DbtDeviceremovecomplete = 0x8004; // device is gone
public const int WmDevicechange = 0x0219; // device change event
private const int DbtDevtypDeviceinterface = 5;
private static readonly Guid GuidDevinterfaceUSBDevice = new Guid("A5DCBF10-6530-11D2-901F-00C04FB951ED"); // USB devices
private static IntPtr notificationHandle;
/// <summary>
/// Registers a window to receive notifications when USB devices are plugged or unplugged.
/// </summary>
/// <param name="windowHandle">Handle to the window receiving notifications.</param>
public static void RegisterUsbDeviceNotification(IntPtr windowHandle)
{
DevBroadcastDeviceinterface dbi = new DevBroadcastDeviceinterface
{
DeviceType = DbtDevtypDeviceinterface,
Reserved = 0,
ClassGuid = GuidDevinterfaceUSBDevice,
Name = 0
};
dbi.Size = Marshal.SizeOf(dbi);
IntPtr buffer = Marshal.AllocHGlobal(dbi.Size);
Marshal.StructureToPtr(dbi, buffer, true);
notificationHandle = RegisterDeviceNotification(windowHandle, buffer, 0);
}
/// <summary>
/// Unregisters the window for USB device notifications
/// </summary>
public static void UnregisterUsbDeviceNotification()
{
UnregisterDeviceNotification(notificationHandle);
}
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr RegisterDeviceNotification(IntPtr recipient, IntPtr notificationFilter, int flags);
[DllImport("user32.dll")]
private static extern bool UnregisterDeviceNotification(IntPtr handle);
[StructLayout(LayoutKind.Sequential)]
private struct DevBroadcastDeviceinterface
{
internal int Size;
internal int DeviceType;
internal int Reserved;
internal Guid ClassGuid;
internal short Name;
}
}
以下是您在 WPF 窗口中使用它的方法（Windows 窗体类似）：
protected override void OnSourceInitialized(EventArgs e)
{
base.OnSourceInitialized(e);
// Adds the windows message processing hook and registers USB device add/removal notification.
HwndSource source = HwndSource.FromHwnd(new WindowInteropHelper(this).Handle);
if (source != null)
{
windowHandle = source.Handle;
source.AddHook(HwndHandler);
UsbNotification.RegisterUsbDeviceNotification(windowHandle);
}
}
/// <summary>
/// Method that receives window messages.
/// </summary>
private IntPtr HwndHandler(IntPtr hwnd, int msg, IntPtr wparam, IntPtr lparam, ref bool handled)
{
if (msg == UsbNotification.WmDevicechange)
{
switch ((int)wparam)
{
case UsbNotification.DbtDeviceremovecomplete:
Usb_DeviceRemoved(); // this is where you do your magic
break;
case UsbNotification.DbtDevicearrival:
Usb_DeviceAdded(); // this is where you do your magic
break;
}
}
handled = false;
return IntPtr.Zero;
}
这是 Windows 窗体的使用示例（甚至更简单）：
public Form1()
{
InitializeComponent();
UsbNotification.RegisterUsbDeviceNotification(this.Handle);
}
protected override void WndProc(ref Message m)
{
base.WndProc(ref m);
if (m.Msg == UsbNotification.WmDevicechange)
{
switch ((int)m.WParam)
{
case UsbNotification.DbtDeviceremovecomplete:
Usb_DeviceRemoved(); // this is where you do your magic
break;
case UsbNotification.DbtDevicearrival:
Usb_DeviceAdded(); // this is where you do your magic
break;
}
}
}
于 2013-04-26T22:04:07.197 回答
14
公认的答案非常好，但它仅适用于 USB 设备。
要使其适用于所有设备（并可选择过滤 USB），请使用以下稍作修改的类：
static class DeviceNotification {
//https://msdn.microsoft.com/en-us/library/aa363480(v=vs.85).aspx
public const int DbtDeviceArrival = 0x8000; // system detected a new device
public const int DbtDeviceRemoveComplete = 0x8004; // device is gone
public const int DbtDevNodesChanged = 0x0007; //A device has been added to or removed from the system.
public const int WmDevicechange = 0x0219; // device change event
private const int DbtDevtypDeviceinterface = 5;
//https://msdn.microsoft.com/en-us/library/aa363431(v=vs.85).aspx
private const int DEVICE_NOTIFY_ALL_INTERFACE_CLASSES = 4;
private static readonly Guid GuidDevinterfaceUSBDevice = new Guid("A5DCBF10-6530-11D2-901F-00C04FB951ED"); // USB devices
private static IntPtr notificationHandle;
/// <summary>
/// Registers a window to receive notifications when devices are plugged or unplugged.
/// </summary>
/// <param name="windowHandle">Handle to the window receiving notifications.</param>
/// <param name="usbOnly">true to filter to USB devices only, false to be notified for all devices.</param>
public static void RegisterDeviceNotification(IntPtr windowHandle, bool usbOnly = false) {
var dbi = new DevBroadcastDeviceinterface {
DeviceType = DbtDevtypDeviceinterface,
Reserved = 0,
ClassGuid = GuidDevinterfaceUSBDevice,
Name = 0
};
dbi.Size = Marshal.SizeOf(dbi);
IntPtr buffer = Marshal.AllocHGlobal(dbi.Size);
Marshal.StructureToPtr(dbi, buffer, true);
notificationHandle = RegisterDeviceNotification(windowHandle, buffer, usbOnly ? 0 : DEVICE_NOTIFY_ALL_INTERFACE_CLASSES);
}
/// <summary>
/// Unregisters the window for device notifications
/// </summary>
public static void UnregisterDeviceNotification() {
UnregisterDeviceNotification(notificationHandle);
}
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr RegisterDeviceNotification(IntPtr recipient, IntPtr notificationFilter, int flags);
[DllImport("user32.dll")]
private static extern bool UnregisterDeviceNotification(IntPtr handle);
[StructLayout(LayoutKind.Sequential)]
private struct DevBroadcastDeviceinterface {
internal int Size;
internal int DeviceType;
internal int Reserved;
internal Guid ClassGuid;
internal short Name;
}
}
关键变化是Flags调用时的参数RegisterDeviceNotification（参见https://msdn.microsoft.com/en-us/library/aa363431(v=vs.85).aspx），如果设置为4而不是0将忽略ClassGuid参数并注册适用于所有设备。
于 2017-03-28T16:06:30.220 回答
2
我来到这篇文章是为了比原始问题更具体的情况，因为我希望在添加或删除端口时收到通知。对于这种情况，答案要简单得多，不需要调用 RegisterDeviceNotification：
DBT_DEVICEARRIVAL 和 DBT_DEVICEREMOVECOMPLETE 事件会自动广播到端口设备的所有顶级窗口。因此，没有必要为端口调用 RegisterDeviceNotification....
https://docs.microsoft.com/en-us/windows/desktop/api/Winuser/nf-winuser-registerdevicenotificationa
所以解决方案变成了这样：
using System.Runtime.InteropServices;
//Put all of the following code inside your Form's partial class:
private struct DEV_BROADCAST_HDR {
internal UInt32 dbch_size;
internal UInt32 dbch_devicetype;
internal UInt32 dbch_reserved;
};
protected override void WndProc(ref Message m) {
base.WndProc(ref m); //This allows window default behavior of base class to be executed
if (m.Msg == 0x0219) { //WM_DEVICECHANGE = 0x0219
DEV_BROADCAST_HDR dbh;
switch ((int)m.WParam) {
case 0x8000: //DBT_DEVICEARRIVAL = 0x8000
dbh = (DEV_BROADCAST_HDR)Marshal.PtrToStructure(m.LParam, typeof(DEV_BROADCAST_HDR));
if (dbh.dbch_devicetype == 0x00000003) { //DBT_DEVTYP_PORT = 0x00000003
Console.WriteLine("Port added!");
//TODO
}
break;
case 0x8004: //DBT_DEVICEREMOVECOMPLETE = 0x8004
dbh = (DEV_BROADCAST_HDR)Marshal.PtrToStructure(m.LParam, typeof(DEV_BROADCAST_HDR));
if (dbh.dbch_devicetype == 0x00000003) { //DBT_DEVTYP_PORT = 0x00000003
Console.WriteLine("Port removed!");
//TODO
}
break;
}
}
}
于 2019-05-17T13:54:07.157 回答
2
这是更好的版本，因为它可以获取端口名称。在 DBT_DEVTYP_PORT 设备类型的情况下，lParam 指向 DEV_BROADCAST_PORT，其中包含 DEV_BROADCAST_HDR，然后以 Unicode 表示要删除或添加的设备的名称以零结尾。
protected override void WndProc(ref Message m)
{
switch ((WndMessage) m.Msg)
{
case WndMessage.WM_DEVICECHANGE:
DEV_BROADCAST_HDR dbh;
switch ((WM_DEVICECHANGE) m.WParam)
{
case WM_DEVICECHANGE.DBT_DEVICEARRIVAL:
case WM_DEVICECHANGE.DBT_DEVICEREMOVECOMPLETE:
dbh = (DEV_BROADCAST_HDR) Marshal.PtrToStructure(m.LParam, typeof(DEV_BROADCAST_HDR));
if ((WM_DEVICECHANGE) dbh.dbch_devicetype == WM_DEVICECHANGE.DBT_DEVTYP_PORT)
{
var portNameBytes = new byte[dbh.dbch_size - (int) WM_DEVICECHANGE.SIZE_OF_DBH];
Marshal.Copy(m.LParam + (int) WM_DEVICECHANGE.SIZE_OF_DBH, portNameBytes, 0, portNameBytes.Length);
string portName = Encoding.Unicode.GetString(portNameBytes).TrimEnd('\0');
if (portName == Settings.Instance.PortName)
{
if ((WM_DEVICECHANGE) m.WParam == WM_DEVICECHANGE.DBT_DEVICEREMOVECOMPLETE)
{
if (!_port.IsOpen)
{
ClosePort();
}
}
else
{
BeginInvoke((Action) (() => OpenPort()));
}
}
}
break;
}
break;
}
base.WndProc(ref m);
}
public enum WndMessage
{
WM_DEVICECHANGE = 0x0219, // device change event
}
public enum WM_DEVICECHANGE
{
// full list: https://docs.microsoft.com/en-us/windows/win32/devio/wm-devicechange
DBT_DEVICEARRIVAL = 0x8000, // A device or piece of media has been inserted and is now available.
DBT_DEVICEREMOVECOMPLETE = 0x8004, // A device or piece of media has been removed.
DBT_DEVTYP_DEVICEINTERFACE = 0x00000005, // Class of devices. This structure is a DEV_BROADCAST_DEVICEINTERFACE structure.
DBT_DEVTYP_HANDLE = 0x00000006, // File system handle. This structure is a DEV_BROADCAST_HANDLE structure.
DBT_DEVTYP_OEM = 0x00000000, // OEM- or IHV-defined device type. This structure is a DEV_BROADCAST_OEM structure.
DBT_DEVTYP_PORT = 0x00000003, // Port device (serial or parallel). This structure is a DEV_BROADCAST_PORT structure.
DBT_DEVTYP_VOLUME = 0x00000002, // Logical volume. This structure is a DEV_BROADCAST_VOLUME structure.
SIZE_OF_DBH = 12, // sizeof(DEV_BROADCAST_HDR)
}
public struct DEV_BROADCAST_HDR
{
internal UInt32 dbch_size;
internal UInt32 dbch_devicetype;
internal UInt32 dbch_reserved;
};
于 2021-05-12T09:34:09.280 回答
0
正如DatuPuti所说：
DBT_DEVICEARRIVAL 和 DBT_DEVICEREMOVECOMPLETE 事件会自动广播到端口设备的所有顶级窗口。因此，不需要为端口调用 RegisterDeviceNotification
所以我采用了他的实现并将其改编为 Windows 窗体：
using System;
using System.Runtime.InteropServices;
private enum WM_DEVICECHANGE
{
// full list: https://docs.microsoft.com/en-us/windows/win32/devio/wm-devicechange
DBT_DEVICEARRIVAL = 0x8000, // A device or piece of media has been inserted and is now available.
DBT_DEVICEREMOVECOMPLETE = 0x8004, // A device or piece of media has been removed.
}
private int WmDevicechange = 0x0219; // device change event
protected override void WndProc(ref Message m)
{
base.WndProc(ref m); //This allows window default behavior of base class to be executed
if (m.Msg == WmDevicechange)
{
switch ((WM_DEVICECHANGE)m.WParam)
{
case WM_DEVICECHANGE.DBT_DEVICEREMOVECOMPLETE:
Console.WriteLine("USB Device removed");
break;
case WM_DEVICECHANGE.DBT_DEVICEARRIVAL:
Console.WriteLine("USB Device added");
break;
}
}
}
于 2021-04-05T15:35:45.747 回答
0
如果您没有 Window，此解决方案将创建一个没有类名及其句柄的通用窗口：
using System;
using System.Windows.Forms;
internal class UsbService : NativeWindow, IDisposable
{
internal UsbService(IEventAggregator eventAggregator)
{
_eventAggregator = eventAggregator;
base.CreateHandle(new CreateParams());
}
protected override void WndProc(ref Message msg)
{
base.WndProc(ref msg);
if (msg.Msg == 0x0219) // Device change event
{
switch (msg.WParam.ToInt32())
{
case 0x8000: // Device added
case 0x8004: // Device removed
_eventAggregator.Publish(...);
break;
}
}
}
public void Dispose()
{
if (!_isDisposed)
{
base.DestroyHandle();
_isDisposed = true;
GC.SuppressFinalize(this);
}
}
private bool _isDisposed;
private IEventAggregator _eventAggregator;
}
我认为在 WPF 项目中使用它会更干净。在这个例子中，我使用 DI 注入了一个事件聚合器，它将发布一个我在不同类中订阅的事件。这可以删除并替换为事件以通知更改。要获得有关连接卷的基本和快速信息，我会使用DriveInfo.GetDrives()方法。
于 2021-12-17T14:08:01.683 回答