从Winusb获取供应商ID和产品ID

我试图从Winusb设备获取供应商和产品ID,并在尝试使用winusb_GetDesicriptor()时遇到accessviolationexception,并且无法弄清楚为什么我会得到该异常.

这是我的声明:

    internal devInfo myDevInfo = new devInfo();
    USB_INTERFACE_DESCRIPTOR ifaceDescriptor;
    USB_DEVICE_DESCRIPTOR deviceDescriptor;


    internal struct USB_INTERFACE_DESCRIPTOR
    {
        internal Byte bLength;
        internal Byte bDescriptorType;
        internal Byte bInterfaceNumber;
        internal Byte bAlternateSetting;
        internal Byte bNumEndpoints;
        internal Byte bInterfaceClass;
        internal Byte bInterfaceSubClass;
        internal Byte bInterfaceProtocol;
        internal Byte iInterface;
    }


    [StructLayout(LayoutKind.Explicit, Size = 18, CharSet = CharSet.Auto)]
    internal struct USB_DEVICE_DESCRIPTOR
    {
        [FieldOffset(0)]internal byte bLength;
        [FieldOffset(1)]internal byte bDescriptorType;
        [FieldOffset(2)]internal ushort bcdUSB;
        [FieldOffset(4)]internal byte bDeviceClass;
        [FieldOffset(5)]internal byte bDeviceSubClass;
        [FieldOffset(6)]internal byte bDeviceProtocol;
        [FieldOffset(7)]internal byte bMaxPacketSize0;
        [FieldOffset(8)]internal ushort idVendor;
        [FieldOffset(10)]internal ushort idProduct;
        [FieldOffset(12)]internal ushort bcdDevice;
        [FieldOffset(14)]internal byte iManufacturer;
        [FieldOffset(15)]internal byte iProduct;
        [FieldOffset(16)]internal byte iSerialNumber;
        [FieldOffset(17)]internal byte bNumConfigurations;
    }

    [DllImport("winusb.dll", SetLastError = true)]
    internal static extern Boolean WinUsb_Initialize(SafeFileHandle DeviceHandle, ref IntPtr InterfaceHandle);

    [DllImport("winusb.dll", SetLastError = true)]
    internal static extern Boolean WinUsb_QueryInterfaceSettings(IntPtr InterfaceHandle, Byte AlternateInterfaceNumber, ref USB_INTERFACE_DESCRIPTOR UsbAltInterfaceDescriptor);

    [DllImport("winusb.dll", SetLastError = true)]
    internal static extern Boolean WinUsb_GetDescriptor(IntPtr InterfaceHandle, byte DescriptorType, byte Index, ushort LanguageID, ref USB_DEVICE_DESCRIPTOR UsbAltDeviceDescriptor, ulong BufferLength, ref long LengthTransferred);

然后这是我试图运行的代码:

deviceHandle = CreateFile
                   (devicePathName,
                   (GENERIC_WRITE | GENERIC_READ),
                   FILE_SHARE_READ | FILE_SHARE_WRITE,
                   IntPtr.Zero,
                   OPEN_EXISTING,
                   FILE_FLAG_OVERLAPPED,
                   0);

            success = WinUsb_Initialize(deviceHandle, ref myDevInfo.winUsbHandle);
            success = WinUsb_QueryInterfaceSettings(myDevInfo.winUsbHandle, 0, ref ifaceDescriptor);
            success = WinUsb_GetDescriptor(myDevInfo.winUsbHandle,
                           0x01,
                           (byte)deviceIndex,
                           0,
                           ref deviceDescriptor,
                           18,
                           ref lengthTransferred);

我正在通过初始化并从queryinterfacesettings获取值,但在GetDescriptor调用上获取访问权限