最近做了一个USB通信SDK, 通过HID跟单片机通信，之前研究了一下Libusb, Cyusb, 要么死的太早，要么封装的不好，最后绕来绕去发现还是HID好用，反编译了一个SimpleHid, 别说，用起来还是很酸爽的~~~
1.设备识别
首先你要指定VID和PID, 这2个不知道的可以不用往下看了，就是一个人的名字和性别
设别识别很容易，直接获取设备列表，对比一下vid,pid就搞定了，不多墨迹了
直接Linq一下了
// 获取所有目标设备信息集合
List<HIDInfoSet> acceptableDevices = HIDManager.GetInfoSets()
.Where(set => this.m_OpenOptions.IsVidAndPidAcceptable(set.Vid, set.Pid))
.ToList();
2.插拔识别
这里有3中方法
方法1.使用winform pnpinvoke 监听消息句柄，判断插拔， 对上位机来说这种方式很常见了，但是有限制，下面说。
方法2.使用cpp dll, 方法1的限制在于有些native软件不能使用winform,比如Unity I2cpp 打包就不行，所以需要自己用C++封装dll，然后使用委托回调函数触发，这个也不难，可以看看我之前的文章
https://blog.csdn.net/gzylongxingtianxia/article/details/136683845
方法3. 简单粗暴，直接开一个监控线程
private void ThreadProcDeviceDiscovery()
{
while (!this.bKillUsbDiscoverThread)
{
this.DoDeviceDiscovery();
Thread.Sleep(200);
}
this.KillDiscoveryThread();
}
监听插拔
/// <summary>
/// The do device discovery.
/// </summary>
private void DoDeviceDiscovery()
{
if (this.m_HidDevices == null)
{
return;
}
// 获取当前已连接的设备的序列号列表
List<string> connectedSerialNumbers = new List<string>();
lock (this.m_HidDevices)
{
foreach (UsbHidDevice device in this.m_HidDevices)
{
connectedSerialNumbers.Add(device.hidInfoSet.SerialNumberString);
}
}
// 获取所有目标设备信息集合
List<HIDInfoSet> acceptableDevices = HIDManager.GetInfoSets()
.Where(set => this.m_OpenOptions.IsVidAndPidAcceptable(set.Vid, set.Pid))
.ToList();
// 获取新发现的设备信息集合
List<HIDInfoSet> newDevices = acceptableDevices
.Where(set => !connectedSerialNumbers.Contains(set.SerialNumberString))
.ToList();
// 获取已断开的设备列表
List<UsbHidDevice> disconnectedDevices = this.m_HidDevices
?.Where(device => !acceptableDevices.Any(set => set.SerialNumberString == device.hidInfoSet.SerialNumberString))
.ToList();
if (disconnectedDevices == null)
{
return;
}
// 断开已断开的设备并移除
foreach (UsbHidDevice device in disconnectedDevices)
{
lock (this.m_HidDevices)
{
this.m_HidDevices.Remove(device);
EventDispatcher.TriggerEvent(EventEnum.DEVICE_DETACHED, device);
}
}
// 实例化新发现的设备并添加到已连接列表中
foreach (HIDInfoSet set in newDevices)
{
UsbHidDevice device = new UsbHidDevice(this, set);
lock (this.m_HidDevices)
{
this.curHidDevice = device;
this.m_HidDevices.Add(device);
}
EventDispatcher.TriggerEvent(EventEnum.DEVICE_ATTACHED, this.curHidDevice);
}
}
3.HID通信
1.创建通信句柄要开启读写
static class DESIREDACCESS
{
public const uint GENERIC_READ = 0x80000000;
public const uint GENERIC_WRITE = 0x40000000;
public const uint GENERIC_EXECUTE = 0x20000000;
public const uint GENERIC_ALL = 0x10000000;
}
this.handle = NativeMethods.CreateFile(devicePath, DESIREDACCESS.GENERIC_READ | DESIREDACCESS.GENERIC_WRITE, 3, IntPtr.Zero, 3, 0x40000000, IntPtr.Zero);
NativeMethods.CreateFile第二个参数要开启读写
2.HidCaps
[StructLayout(LayoutKind.Sequential, Pack=1)]
public struct HidCaps
{
public short Usage;
public short UsagePage;
public short InputReportByteLength;
public short OutputReportByteLength;
public short FeatureReportByteLength;
[MarshalAs(UnmanagedType.ByValArray, SizeConst=0x11)]
public short[] Reserved;
public short NumberLinkCollectionNodes;
public short NumberInputButtonCaps;
public short NumberInputValueCaps;
public short NumberInputDataIndices;
public short NumberOutputButtonCaps;
public short NumberOutputValueCaps;
public short NumberOutputDataIndices;
public short NumberFeatureButtonCaps;
public short NumberFeatureValueCaps;
public short NumberFeatureDataIndices;
}
InputReportByteLength 和 OutputReportByteLength 这2个长度很重要，一般是65个字节，ReportId + Data
3. 构建报文数据
Report Id 单个包来说都是 0 ，如果一次发多个包，就要递增，我这里是一个包的情况
总长度 0x41 = 65 , ReportId + Data ，数据占64个字节
长度一定不能错，否则会包HID参数异常
下面是一个参考方法
public void MakeBytes(EMessage cmd, byte value)
{
this.reportId = 0;
this.value = (int)value;
this.length = 1;
this.cmd = (int)cmd;
var i = 0;
this.sendData = new byte[0x41];
this.sendData[i] = this.reportId;
this.sendData[i++] = 0x05;
this.sendData[i++] = 0XAA;
this.sendData[i++] = 0XAA;
this.sendData[i++] = (byte)cmd;
this.sendData[i++] = 1;
this.sendData[i++] = value;
for (; i < 0x41; i++)
{
this.sendData[i] = 0;
}
}
4. 读写
当设备连接成功后，会建立一个字节流
this.fileStream = new FileStream(new SafeFileHandle(this.handle, false), FileAccess.ReadWrite, this.hidCaps.InputReportByteLength, true);
通过这个字节流读写数据
public byte[] ReadRawInputReport()
{
byte reportID = 0;
byte[] buffer = this.CreateRawInputReport(reportID);
try
{
this.fileStream.Read(buffer, 0, buffer.Length);
}
catch (Exception e)
{
return buffer;
}
return buffer;
}
public void WriteRawOutputReport(byte[] data)
{
try
{
this.fileStream.Write(data, 0, data.Length);
this.fileStream.Flush();
}
catch (Exception e)
{
throw new HIDDeviceException();
}
}
Ojbkey了，剩下的开多少个线程，如何处理发送接收就自己发挥吧，也比较简单，下班了，周末愉快，老铁们~~！！
