Receiving Windows messages in Unity

I need to react to the event of a USB device being unplugged and plugged in. I found a solution for Windows Forms reacting to the WM_DEVICECHANGE message sent by the system. In plain C# it works really well, but I can't get it to work with unity. Are there any ideas?

Following is the code I used for testing with Windows Forms:

 using System;
 using System.Collections.Generic;
 using System.ComponentModel;
 using System.Data;
 using System.Drawing;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 using System.Windows.Forms;
 using System.Runtime.InteropServices;
 
 namespace HardwareServiceTest
 {
 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
         public const int DbtConfigChanged = 0x0018;
         public const int DbtDeviceSpecific = 0x8005;
         public const int DbtDevnodesChanged = 0x0007;
         private const int DbtDevtypDeviceinterface = 5;
         private static readonly Guid GuidDevinterfaceUSBDevice = new Guid("A5DCBF10-6530-11D2-901F-00C04FB951ED"); // USB 
         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;
         }
     }
     
 
     public partial class Form1 : Form
     {
         [DllImport("user32.dll", SetLastError = true)]
         static extern IntPtr FindWindow(string lpClassName, string lpWindowName);
         
         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;
                     case UsbNotification.DbtConfigChanged:
                         Usb_ConfigChanged();
                         break;
                     case UsbNotification.DbtDevnodesChanged:
                         Usb_NodesChanged();
                         break;
                 }
             }
         }
         public void Usb_DeviceRemoved()
         {
             label1.Text = "A USB device was removed!";
         }
 
         public void Usb_DeviceAdded()
         {
             label1.Text = "A USB device was added!";
         }
         public void Usb_ConfigChanged()
         {
             label1.Text = "Config changed!";
         }
         public void Usb_NodesChanged()
         {
             label1.Text = "Nodes changed!";
         }
     }
    
 }