【C#】HID API

范例下载地址：https://download.youkuaiyun.com/download/u010875635/10689911

Windows使用HID通信相对比较简单，HID都是通过PID、VID信息来查找连接的，相比于串口，几乎无变化，连接无需人工选择，十分方便，也不需要驱动。

下面上实例，PID为0x003f，VID为0x04D8，支持发送接收数据显示到UI，使用C#来编写，调用的是windows api（create file、read file、write file）。

本实例将HID接口分成3层，支持自动连接、断开状态通知，异步收发数据，单个数据包大小为64bytes（因为从设备的数据包设定为64bytes，保持一致）。

接口分为两层，第一层将create file、read file、write file封装，第二层再封装自动连接、异步收发。

Hid.cs -> HIDInterface.cs -> 应用

注意，这里所有数据都是64bytes，但是有用数据并非这么多，所以设定为第一个数据为后面数据实际长度，若需要修改定义，请在HIDInterface.cs的Send与HidDataReceived函数中修改处理方法即可。

 

Hid.cs

 

using System;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using System.IO;
using Microsoft.Win32.SafeHandles;
using System.Windows;

namespace HID_SIMPLE.HID
{
    public class report : EventArgs
    {
        public readonly byte reportID;
        public readonly byte[] reportBuff;
        public report(byte id, byte[] arrayBuff)
        {
            reportID = id;
            reportBuff = arrayBuff;
        }
    }
    public class Hid : object
    {
        private IntPtr INVALID_HANDLE_VALUE = new IntPtr(-1);
        private const int MAX_USB_DEVICES = 64;
        private bool deviceOpened = false;
        private FileStream hidDevice = null;
        private IntPtr hHubDevice;
        
        int outputReportLength;//输出报告长度,包刮一个字节的报告ID
        public int OutputReportLength { get { return outputReportLength; } }
        int inputReportLength;//输入报告长度,包刮一个字节的报告ID   
        public int InputReportLength { get { return inputReportLength; } }

        /// <summary>
        /// 打开指定信息的设备
        /// </summary>
        /// <param name="vID">设备的vID</param>
        /// <param name="pID">设备的pID</param>
        /// <param name="serial">设备的serial</param>
        /// <returns></returns>
        public HID_RETURN OpenDevice(UInt16 vID, UInt16 pID, string serial)
        {
            if (deviceOpened == false)
            {
                //获取连接的HID列表
                List<string> deviceList = new List<string>();
                GetHidDeviceList(ref deviceList);
                if (deviceList.Count == 0)
                    return HID_RETURN.NO_DEVICE_CONECTED;
                for (int i = 0; i < deviceList.Count; i++)
                {
                    IntPtr device = CreateFile(deviceList[i],
                                                DESIREDACCESS.GENERIC_READ | DESIREDACCESS.GENERIC_WRITE,
                                                0,
                                                0,
                                                CREATIONDISPOSITION.OPEN_EXISTING,
                                                FLAGSANDATTRIBUTES.FILE_FLAG_OVERLAPPED,
                                                0);
                    if (device != INVALID_HANDLE_VALUE)
                    {
                        HIDD_ATTRIBUTES attributes;
                        IntPtr serialBuff = Marshal.AllocHGlobal(512);
                        HidD_GetAttributes(device, out attributes);
                        HidD_GetSerialNumberString(device, serialBuff, 512);
                        string deviceStr = Marshal.PtrToStringAuto(serialBuff);
                        Marshal.FreeHGlobal(serialBuff);
                        if (attributes.VendorID == vID && attributes.ProductID == pID && deviceStr.Contains(serial))
                        {
                            IntPtr preparseData;
                            HIDP_CAPS caps;
                            HidD_GetPreparsedData(device, out preparseData);
                            HidP_GetCaps(preparseData, out caps);
                            HidD_FreePreparsedData(preparseData);
                            outputReportLength = caps.OutputReportByteLength;
                            inputReportLength = caps.InputReportByteLength;

                            hidDevice = new FileStream(new SafeFileHandle(device, false), FileAccess.ReadWrite, inputReportLength, true);
                            deviceOpened = true;
                            BeginAsyncRead();

                            hHubDevice = device;
                            return HID_RETURN.SUCCESS;
                        }
                    }
                }
                return HID_RETURN.DEVICE_NOT_FIND;
            }
            else
                return HID_RETURN.DEVICE_OPENED;
        }

        /// <summary>
        /// 关闭打开的设备
        /// </summary>
        public void CloseDevice()
        {
            if (deviceOpened == true)
            {
                deviceOpened = false;
                hidDevice.Close();
            }
        }

        /// <summary>
        /// 开始一次异步读
        /// </summary>
        private void BeginAsyncRead()
        {
            byte[] inputBuff = new byte[InputReportLength];
            hidDevice.BeginRead(inputBuff, 0, InputReportLength, new AsyncCallback(ReadCompleted), inputBuff);
        }

        /// <summary>
        /// 异步读取结束,发出有数据到达事件
        /// </summary>
        /// <param name="iResult">这里是输入报告的数组</param>
        private void ReadCompleted(IAsyncResult iResult)
        {
            byte[] readBuff = (byte[])(iResult.AsyncState);
            try
            {
                hidDevice.EndRead(iResult);//读取结束,如果读取错误就会产生一个异常
                byte[] reportData = new byte[readBuff.Length - 1];
                for (int i = 1; i < readBuff.Length; i++)
                    reportData[i - 1] = readBuff[i];
                report e = new report(readBuff[0], reportData);
                OnDataReceived(e); //发出数据到达消息
                if (!deviceOpened) return;
                BeginAsyncRead();//启动下一次读操作
            }
            catch //读写错误,设备已经被移除
            {
                //MyConsole.WriteLine("设备无法连接，请重新插入设备");
                EventArgs ex = new EventArgs();
                OnDeviceRemoved(ex);//发出设备移除消息
                CloseDevice();

            }
        }

        public delegate void DelegateDataReceived(object sender, report e);
        //public event EventHandler<ConnectEventArg> StatusConnected;
       
        public DelegateDataReceived DataReceived;

        /// <summary>
        /// 事件:数据到达,处理此事件以接收输入数据
        /// </summary>
        
        protected virtual void OnDataReceived(report e)
        {
            if (DataReceived != null) DataReceived(this, e);
        }

        /// <summary>
        /// 事件:设备断开
        /// </summary>

        public delegate void DelegateStatusConnected(object sender, EventArgs e);
        public DelegateStatusConnected DeviceRemoved;
        protected virtual void OnDeviceRemoved(EventArgs e)
        {
            if (DeviceRemoved != null) DeviceRemoved(this,e);
        }

        /// <summary>
        /// 
        /// </summar