Win32Usb.WM_DEVICECHANGE的问题

[dceacho]

代码很简单，USB设备状态变化事件里处理一些东西，
但我插拔USB后这里的参数值m.WParam值为0x07 不是Win32Usb.WM_DEVICECHANGE也不是Win32Usb.DEVICE_REMOVECOMPLETE: Win32USb.cs里也没找到0x07代表什么

        public void ParseMessages(ref Message m)
        {
            if (m.Msg == Win32Usb.WM_DEVICECHANGE)	// we got a device change message! A USB device was inserted or removed
            {
                switch (m.WParam.ToInt32())	// Check the W parameter to see if a device was inserted or removed
                {
                    case Win32Usb.DEVICE_ARRIVAL:	// inserted
                        if (OnDeviceArrived != null)
                        {
                            OnDeviceArrived(this, new System.EventArgs());
                            CheckDevicePresent();
                        }
                        break;
                    case Win32Usb.DEVICE_REMOVECOMPLETE:	// removed
                        if (OnDeviceRemoved != null)
                        {
                            OnDeviceRemoved(this, new System.EventArgs());
                            CheckDevicePresent();
                        }
                        break;
                }
            }
        }

Win32USB.cs里各值的定义

       #region Constants
		/// <summary>Windows message sent when a device is inserted or removed</summary>
		public const int WM_DEVICECHANGE = 0x0219;
		/// <summary>WParam for above : A device was inserted</summary>
		public const int DEVICE_ARRIVAL = 0x8000;
		/// <summary>WParam for above : A device was removed</summary>
		public const int DEVICE_REMOVECOMPLETE = 0x8004;
		/// <summary>Used in SetupDiClassDevs to get devices present in the system</summary>
        protected const int DIGCF_PRESENT = 0x02;
		/// <summary>Used in SetupDiClassDevs to get device interface details</summary>
		protected const int DIGCF_DEVICEINTERFACE = 0x10;
		/// <summary>Used when registering for device insert/remove messages : specifies the type of device</summary>
		protected const int DEVTYP_DEVICEINTERFACE = 0x05;
		/// <summary>Used when registering for device insert/remove messages : we're giving the API call a window handle</summary>
		protected const int DEVICE_NOTIFY_WINDOW_HANDLE = 0;
        /// <summary>Purges Win32 transmit buffer by aborting the current transmission.</summary>
        protected const uint PURGE_TXABORT = 0x01;
        /// <summary>Purges Win32 receive buffer by aborting the current receive.</summary>
        protected const uint PURGE_RXABORT = 0x02;
        /// <summary>Purges Win32 transmit buffer by clearing it.</summary>
        protected const uint PURGE_TXCLEAR = 0x04;
        /// <summary>Purges Win32 receive buffer by clearing it.</summary>
        protected const uint PURGE_RXCLEAR = 0x08;
        /// <summary>CreateFile : Open file for read</summary>
        protected const uint GENERIC_READ = 0x80000000;
        /// <summary>CreateFile : Open file for write</summary>
        protected const uint GENERIC_WRITE = 0x40000000;
        /// <summary>CreateFile : file share for write</summary>
        protected const uint FILE_SHARE_WRITE = 0x2;
        /// <summary>CreateFile : file share for read</summary>
        protected const uint FILE_SHARE_READ = 0x1;
        /// <summary>CreateFile : Open handle for overlapped operations</summary>
        protected const uint FILE_FLAG_OVERLAPPED = 0x40000000;
        /// <summary>CreateFile : Resource to be "created" must exist</summary>
        protected const uint OPEN_EXISTING = 3;
        /// <summary>CreateFile : Resource will be "created" or existing will be used</summary>
        protected const uint OPEN_ALWAYS = 4;
        /// <summary>ReadFile/WriteFile : Overlapped operation is incomplete.</summary>
        protected const uint ERROR_IO_PENDING = 997;
        /// <summary>Infinite timeout</summary>
        protected const uint INFINITE = 0xFFFFFFFF;
        /// <summary>Simple representation of a null handle : a closed stream will get this handle. Note it is public for comparison by higher level classes.</summary>
        public static IntPtr NullHandle = IntPtr.Zero;
        /// <summary>Simple representation of the handle returned when CreateFile fails.</summary>
        protected static IntPtr InvalidHandleValue = new IntPtr(-1);
        #endregion

[飞天凤凰601]

版主，是不是想得到U盘插入和拨出的状态？

[飞天凤凰601]

DEVICE_ARRIVAL＝0x8000; DEVICE_REMOVECOMPLETE＝0x8004; 你试试这2个值。

[飞天凤凰601]

刚才看了，你的值也是这个 你看看你的U盘，增加的盘符是不是“硬盘”的盘符,而不是“可移动存储”的盘符。 如果是，哪就不行，我编的程序，曾经碰上过这种问题，呵呵 必须是“可移动存储”，才起作用。