如何通过VID和PID获取设备的COM口

hmmvj575 2015-09-23 10:03:32

我的需求是这样的
描述：当USB设备插入电脑之后，通过VID和PID获取他的COM口是多少
问题：现在网上找一份源码，但是里面有些问题，请大神解答！



using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

using System.Management;

using System.Text.RegularExpressions;

using System.Runtime.InteropServices;



namespace 获取设备的VID__PID

{



    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

            this.Load += delegate { RegisterUsbDeviceNotification(); };

            this.FormClosed += delegate { /* UnregisterDeviceNotification(cookie); */};

        }



        private void RegisterUsbDeviceNotification()

        {

            var filter = new DEV_BROADCAST_DEVICEINTERFACEW()

            {

                hdr = new DEV_BROADCAST_HDR()

                {

                    dbch_Size = DEV_BROADCAST_DEVICEINTERFACEW.Size,

                    dbch_DeviceType = DBT_DEVTYP_DEVICEINTERFACE,

                },

                dbcc_classguid = GUID_DEVINTERFACE_USB_DEVICE

            };



            IntPtr cookie = RegisterDeviceNotification(  // 1

                this.Handle,

                ref filter,

                DEVICE_NOTIFY_WINDOW_HANDLE);

        }

         protected override void WndProc(ref Message m)

        {

            if (m.Msg == WM_DEVICECHANGE)

            {

                switch (m.WParam.ToInt32())

                {

                    case DBT_DEVICEARRIVAL:

                        var hdr = (DEV_BROADCAST_HDR)Marshal.PtrToStructure(m.LParam, typeof(DEV_BROADCAST_HDR));

                        if (hdr.dbch_DeviceType == DBT_DEVTYP_DEVICEINTERFACE)

                        {

                            IntPtr pName = m.LParam + DEV_BROADCAST_DEVICEINTERFACEW.Size - sizeof(char);

                            string name = Marshal.PtrToStringUni(pName);  // 2得到设备路径，类似\?\USB#VID_05AC&PID_1294&MI_00#0#{6bdd1fc6-810f-11d0-bec7-08002be2092f}。

                            var match = Regex.Match(name, @"USB#VID_(?<vid>\w{4})&PID_(?<pid>\w{4})");

                            if (match.Success) //3VID和PID可以在USB的设备路径中得到。

                            {

                                this.Text = string.Format(

                                    "vid={0} pid={1}",

                                    match.Groups["vid"].Value,

                                    match.Groups["pid"].Value

                                    );

                            }

                        }

                        break;

                    case DBT_DEVICEREMOVECOMPLETE:

                        break;

                }

            }

            base.WndProc(ref m);

        }

        const int WM_DEVICECHANGE = 0x219;

        const int DBT_DEVICEARRIVAL = 0x00008000;

        const int DBT_DEVICEREMOVECOMPLETE = 0x8004;

        const int DBT_DEVTYP_DEVICEINTERFACE = 0x00000005;

        const int DEVICE_NOTIFY_WINDOW_HANDLE = 0x00000000;

        static Guid GUID_DEVINTERFACE_USB_DEVICE = new Guid("{A5DCBF10-6530-11D2-901F-00C04FB951ED}");

 

        [DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Unicode)]

        static extern IntPtr RegisterDeviceNotification(

            IntPtr hRecipient,

            ref DEV_BROADCAST_DEVICEINTERFACEW NotificationFilter, 

            uint Flags);

 

        [StructLayout(LayoutKind.Sequential)]

        struct DEV_BROADCAST_HDR

        {

            public int dbch_Size;

            public int dbch_DeviceType;

            public int dbch_Reserved;

        }

 

        [StructLayout(LayoutKind.Sequential)]

        struct DEV_BROADCAST_DEVICEINTERFACEW

        {

            public DEV_BROADCAST_HDR hdr;

            public Guid dbcc_classguid;

            public char dbcc_name;

            public static readonly int Size = Marshal.SizeOf(typeof(DEV_BROADCAST_DEVICEINTERFACEW));

        }

    }

}