c# - 从 Winusb 获取供应商 ID 和产品 ID

Question

我正在尝试从 Winusb 设备获取供应商和产品 ID，并在尝试使用 winusb_GetDesicriptor() 时遇到 accessviolationexception，但无法弄清楚为什么我会收到该异常。

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);

然后这是我要运行的代码:

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);

我正在完成初始化并从 queryinterfacesettings 取回值，但在 GetDescriptor 调用中遇到访问冲突

Answer 1

阅读documentation for WinUsb_GetDescriptor .

看起来你的参数不正确。要获取设备描述符中的 VID/PID，您需要为第二个参数 (0x01) 指定 USB_DEVICE_DESCRIPTOR_TYPE 类型。如果您请求字符串描述符，您也只需要指定语言 ID。你的设备描述符的长度也是错误的，它应该是 18(ushort 是 2 个字节，这可能是你的访问冲突的原因)。您还想在 DeviceDescriptor 结构中使用 byte 而不是 Byte，您不需要字节的 .NET 类表示，只是类型值本身。

以下是可能适合您的更新代码:

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