C# 连蒙带骗不知所以然的搞定USB下位机读写
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2022-07-02 22:30:19
公司用了一台发卡机，usb接口，半双工，给了个dll，不支持线程操作，使得UI线程老卡。 懊恼了，想自己直接通过usb读写，各种百度，然后是无数的坑，最终搞定。 现将各种坑和我自己的某些猜想记录一下，也供各位参考。 一、常量定义 主要用于CreateFile时用。 二、结构、枚举、类定义 都是从各种 ......
公司用了一台发卡机，usb接口，半双工，给了个dll，不支持线程操作，使得UI线程老卡。
懊恼了，想自己直接通过usb读写，各种百度，然后是无数的坑，最终搞定。
现将各种坑和我自己的某些猜想记录一下，也供各位参考。
一、常量定义
private const short INVALID_HANDLE_VALUE = -1;
private const uint GENERIC_READ = 0x80000000;
private const uint GENERIC_WRITE = 0x40000000;
private const uint FILE_SHARE_READ = 0x00000001;
private const uint FILE_SHARE_WRITE = 0x00000002;
private const uint CREATE_NEW = 1;
private const uint CREATE_ALWAYS = 2;
private const uint OPEN_EXISTING = 3;
private const uint FILE_FLAG_OVERLAPPED = 0x40000000;
private const uint FILE_ATTRIBUTE_NORMAL = 0x00000080;
主要用于CreateFile时用。
二、结构、枚举、类定义
private struct HID_ATTRIBUTES
{
public int Size;
public ushort VendorID;
public ushort ProductID;
public ushort VersionNumber;
}
private struct SP_DEVICE_INTERFACE_DATA
{
public int cbSize;
public Guid interfaceClassGuid;
public int flags;
public int reserved;
}
[StructLayout(LayoutKind.Sequential)]
private class SP_DEVINFO_DATA
{
public int cbSize = Marshal.SizeOf<SP_DEVINFO_DATA>();
public Guid classGuid = Guid.Empty;
public int devInst = 0;
public int reserved = 0;
}
[StructLayout(LayoutKind.Sequential, Pack = 2)]
private struct SP_DEVICE_INTERFACE_DETAIL_DATA
{
internal int cbSize;
internal short devicePath;
}
private enum DIGCF
{
DIGCF_DEFAULT = 0x1,
DIGCF_PRESENT = 0x2,
DIGCF_ALLCLASSES = 0x4,
DIGCF_PROFILE = 0x8,
DIGCF_DEVICEINTERFACE = 0x10
}
[StructLayout(LayoutKind.Sequential)]
private struct HIDP_CAPS
{
/// <summary>
/// Specifies a top-level collection's usage ID.
/// </summary>
public System.UInt16 Usage;
/// <summary>
/// Specifies the top-level collection's usage page.
/// </summary>
public System.UInt16 UsagePage;
/// <summary>
/// 输入报告的最大节数数量（如果使用报告ID，则包含报告ID的字节）
/// Specifies the maximum size, in bytes, of all the input reports (including the report ID, if report IDs are used, which is prepended to the report data).
/// </summary>
public System.UInt16 InputReportByteLength;
/// <summary>
/// Specifies the maximum size, in bytes, of all the output reports (including the report ID, if report IDs are used, which is prepended to the report data).
/// </summary>
public System.UInt16 OutputReportByteLength;
/// <summary>
/// Specifies the maximum length, in bytes, of all the feature reports (including the report ID, if report IDs are used, which is prepended to the report data).
/// </summary>
public System.UInt16 FeatureReportByteLength;
/// <summary>
/// Reserved for internal system use.
/// </summary>
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 17)]
public System.UInt16[] Reserved;
/// <summary>
/// pecifies the number of HIDP_LINK_COLLECTION_NODE structures that are returned for this top-level collection by HidP_GetLinkCollectionNodes.
/// </summary>
public System.UInt16 NumberLinkCollectionNodes;
/// <summary>
/// Specifies the number of input HIDP_BUTTON_CAPS structures that HidP_GetButtonCaps returns.
/// </summary>
public System.UInt16 NumberInputButtonCaps;
/// <summary>
/// Specifies the number of input HIDP_VALUE_CAPS structures that HidP_GetValueCaps returns.
/// </summary>
public System.UInt16 NumberInputValueCaps;
/// <summary>
/// Specifies the number of data indices assigned to buttons and values in all input reports.
/// </summary>
public System.UInt16 NumberInputDataIndices;
/// <summary>
/// Specifies the number of output HIDP_BUTTON_CAPS structures that HidP_GetButtonCaps returns.
/// </summary>
public System.UInt16 NumberOutputButtonCaps;
/// <summary>
/// Specifies the number of output HIDP_VALUE_CAPS structures that HidP_GetValueCaps returns.
/// </summary>
public System.UInt16 NumberOutputValueCaps;
/// <summary>
/// Specifies the number of data indices assigned to buttons and values in all output reports.
/// </summary>
public System.UInt16 NumberOutputDataIndices;
/// <summary>
/// Specifies the total number of feature HIDP_BUTTONS_CAPS structures that HidP_GetButtonCaps returns.
/// </summary>
public System.UInt16 NumberFeatureButtonCaps;
/// <summary>
/// Specifies the total number of feature HIDP_VALUE_CAPS structures that HidP_GetValueCaps returns.
/// </summary>
public System.UInt16 NumberFeatureValueCaps;
/// <summary>
/// Specifies the number of data indices assigned to buttons and values in all feature reports.
/// </summary>
public System.UInt16 NumberFeatureDataIndices;
}
都是从各种地方复制过来的。最后的结构注释从微软那里复制了英文，翻译了一句中文。因为这个坑最大。
三、Dll封装
/// <summary>
/// 过滤设备，获取需要的设备
/// </summary>
/// <param name="ClassGuid"></param>
/// <param name="Enumerator"></param>
/// <param name="HwndParent"></param>
/// <param name="Flags"></param>
/// <returns></returns>
[DllImport("setupapi.dll", SetLastError = true)]
private static extern IntPtr SetupDiGetClassDevs(ref Guid ClassGuid, uint Enumerator, IntPtr HwndParent, DIGCF Flags);
/// <summary>
/// 获取设备，true获取到
/// </summary>
/// <param name="hDevInfo"></param>
/// <param name="devInfo"></param>
/// <param name="interfaceClassGuid"></param>
/// <param name="memberIndex"></param>
/// <param name="deviceInterfaceData"></param>
/// <returns></returns>
[DllImport("setupapi.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern Boolean SetupDiEnumDeviceInterfaces(IntPtr hDevInfo, IntPtr devInfo, ref Guid interfaceClassGuid, UInt32 memberIndex, ref SP_DEVICE_INTERFACE_DATA deviceInterfaceData);
/// <summary>
/// 获取接口的详细信息 必须调用两次 第1次返回长度 第2次获取数据
/// </summary>
/// <param name="deviceInfoSet"></param>
/// <param name="deviceInterfaceData"></param>
/// <param name="deviceInterfaceDetailData"></param>
/// <param name="deviceInterfaceDetailDataSize"></param>
/// <param name="requiredSize"></param>
/// <param name="deviceInfoData"></param>
/// <returns></returns>
[DllImport("setupapi.dll", SetLastError = true, CharSet = CharSet.Auto)]
private static extern bool SetupDiGetDeviceInterfaceDetail(IntPtr deviceInfoSet, ref SP_DEVICE_INTERFACE_DATA deviceInterfaceData, IntPtr deviceInterfaceDetailData, int deviceInterfaceDetailDataSize, ref int requiredSize, SP_DEVINFO_DATA deviceInfoData);
/// <summary>
/// 删除设备信息并释放内存
/// </summary>
/// <param name="HIDInfoSet"></param>
/// <returns></returns>
[DllImport("setupapi.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern Boolean SetupDiDestroyDeviceInfoList(IntPtr HIDInfoSet);
/// <summary>
/// 获取设备文件
/// </summary>
/// <param name="lpFileName"></param>
/// <param name="dwDesiredAccess">access mode</param>
/// <param name="dwShareMode">share mode</param>
/// <param name="lpSecurityAttributes">SD</param>
/// <param name="dwCreationDisposition">how to create</param>
/// <param name="dwFlagsAndAttributes">file attributes</param>
/// <param name="hTemplateFile">handle to template file</param>
/// <returns></returns>
[DllImport("kernel32.dll", SetLastError = true)]
private static extern IntPtr CreateFile(string lpFileName, uint dwDesiredAccess, uint dwShareMode, uint lpSecurityAttributes, uint dwCreationDisposition, uint dwFlagsAndAttributes, uint hTemplateFile);
[DllImport("kernel32.dll", SetLastError = true)]
[return: System.Runtime.InteropServices.MarshalAsAttribute(System.Runtime.InteropServices.UnmanagedType.Bool)]
private static extern bool WriteFile(System.IntPtr hFile, byte[] lpBuffer, uint nNumberOfBytesToWrite, out uint lpNumberOfBytesWritten, IntPtr lpOverlapped);
[DllImport("kernel32.dll", SetLastError = true)]
private static extern int CloseHandle(int hObject);
/// <summary>
/// 获得GUID
/// </summary>
/// <param name="HidGuid"></param>
[DllImport("hid.dll")]
private static extern void HidD_GetHidGuid(ref Guid HidGuid);
[DllImport("hid.dll")]
private static extern Boolean HidD_GetPreparsedData(IntPtr hidDeviceObject, out IntPtr PreparsedData);
[DllImport("hid.dll")]
private static extern uint HidP_GetCaps(IntPtr PreparsedData, out HIDP_CAPS Capabilities);
[DllImport("hid.dll")]
private static extern Boolean HidD_FreePreparsedData(IntPtr PreparsedData);
[DllImport("hid.dll")]
private static extern Boolean HidD_GetAttributes(IntPtr hidDevice, out HID_ATTRIBUTES attributes);
四、几个属性
private int _InputBufferSize;
private int _OutputBufferSize;
private FileStream _UsbFileStream = null;
五、几个方法
Usb设备的读写跟磁盘文件的读写没区别，需要打开文件、读文件、写文件，最后关闭文件。
磁盘文件大家都清楚，比如“c:\data\hello.txt”就是个文件名，前面加“\\计算机A”则是其他计算机上的某文件名，Usb设备也有文件名，如我的设备的文件名就是“\\?\hid#vid_5131&pid_2007#7&252e9bc9&0&0000#{4d1e55b2-f16f-11cf-88cb-001111000030}”。
哪弄来的？头大了吧，我也头大，什么鬼？百度了，未果，所以干脆不管了。先来一个列出全部Usb设备文件名的方法
（一）获取所有Usb设备文件名
/// <summary>
/// 获取所有Usb设备文件名
/// </summary>
/// <returns></returns>
public static List<string> GetUsbFileNames()
{
List<string> items = new List<string>();
//通过一个空的GUID来获取HID的全局GUID。
Guid hidGuid = Guid.Empty;
HidD_GetHidGuid(ref hidGuid);
//通过获取到的HID全局GUID来获取包含所有HID接口信息集合的句柄。
IntPtr hidInfoSet = SetupDiGetClassDevs(ref hidGuid, 0, IntPtr.Zero, DIGCF.DIGCF_PRESENT | DIGCF.DIGCF_DEVICEINTERFACE);
//获取接口信息。
if (hidInfoSet != IntPtr.Zero)
{
SP_DEVICE_INTERFACE_DATA interfaceInfo = new SP_DEVICE_INTERFACE_DATA();
interfaceInfo.cbSize = Marshal.SizeOf(interfaceInfo);
uint index = 0;
//检测集合的每个接口
while (SetupDiEnumDeviceInterfaces(hidInfoSet, IntPtr.Zero, ref hidGuid, index, ref interfaceInfo))
{
int bufferSize = 0;
//获取接口详细信息；第一次读取错误，但可取得信息缓冲区的大小
SP_DEVINFO_DATA strtInterfaceData = new SP_DEVINFO_DATA();
var result = SetupDiGetDeviceInterfaceDetail(hidInfoSet, ref interfaceInfo, IntPtr.Zero, 0, ref bufferSize, null);
//第二次调用传递返回值，调用即可成功
IntPtr detailDataBuffer = Marshal.AllocHGlobal(bufferSize);
Marshal.StructureToPtr(
new SP_DEVICE_INTERFACE_DETAIL_DATA
{
cbSize = Marshal.SizeOf(typeof(SP_DEVICE_INTERFACE_DETAIL_DATA))
}, detailDataBuffer, false);
if (SetupDiGetDeviceInterfaceDetail(hidInfoSet, ref interfaceInfo, detailDataBuffer, bufferSize, ref bufferSize, null))// strtInterfaceData))
{
string devicePath = Marshal.PtrToStringAuto(IntPtr.Add(detailDataBuffer, 4));
items.Add(devicePath);
}
Marshal.FreeHGlobal(detailDataBuffer);
index++;
}
}
//删除设备信息并释放内存
SetupDiDestroyDeviceInfoList(hidInfoSet);
return items;
}
一般会返回好几个文件名，那哪个是你要的呢？方法有二：
1.先获取一次文件名列表，然后插拔或者禁用启用一次Usb设备，变化的那个就是
2.轮流写然后读一次文件名，获取到正确结果的就是
我采用2，然后User.config里面把他记下来。
要读写，首先要打开
（二）打开Usb设备
/// <summary>
/// 构造
/// </summary>
/// <param name="usbFileName">Usb Device Path</param>
public UsbApi(string usbFileName)
{
if (string.IsNullOrEmpty(usbFileName))
throw new Exception("文件名不能为空");
var fileHandle = CreateFile(
usbFileName,
GENERIC_READ | GENERIC_WRITE,// | GENERIC_WRITE,//读写，或者一起
FILE_SHARE_READ | FILE_SHARE_WRITE,//共享读写，或者一起
0,
OPEN_EXISTING,//必须已经存在
FILE_ATTRIBUTE_NORMAL | FILE_FLAG_OVERLAPPED,
0);
if (fileHandle == IntPtr.Zero || (int)fileHandle == -1)
throw new Exception("打开文件失败");
HidD_GetAttributes(fileHandle, out var attributes);// null);// out var aa);
HidD_GetPreparsedData(fileHandle, out var preparseData);
HidP_GetCaps(preparseData, out var caps);
HidD_FreePreparsedData(preparseData);
_InputBufferSize = caps.InputReportByteLength;
_OutputBufferSize = caps.OutputReportByteLength;
_UsbFileStream = new FileStream(new SafeFileHandle(fileHandle, true), FileAccess.ReadWrite, System.Math.Max(caps.OutputReportByteLength, caps.InputReportByteLength), true);
}
打开Usb设备我是在构找函数里面完成的，我的类名叫UsbApi。
（三）写
/// <summary>
/// 写数据
/// </summary>
/// <param name="array"></param>
public void Write(byte[] data)
{
if (_UsbFileStream == null)
throw new Exception("Usb设备没有初始化");
if (data.Length > _OutputBufferSize)
throw new Exception($"数据太长，超出缓冲区长度({_OutputBufferSize})");
byte[] outBuffer = new byte[_OutputBufferSize];
Array.Copy(data, 0, outBuffer, 1, data.Length);
_UsbFileStream.Write(outBuffer, 0, _OutputBufferSize);
}
（四）读
/// <summary>
/// 同步读
/// </summary>
/// <param name="array"></param>
public byte[] Read()
{
if (_UsbFileStream == null)
throw new Exception("Usb设备没有初始化");
byte[] inBuffer = new byte[_InputBufferSize];
_UsbFileStream.Read(inBuffer, 0, _InputBufferSize);
return inBuffer;
}
我的Usb设备是半双工的，并且数据只有64字节，所有用了同步读。
（五）关闭
public void Close()
{
if (_UsbFileStream != null)
_UsbFileStream.Close();
}
六、最后
最后写了几行代码测试，巨坑：
1.CreateFile参数的坑
var fileHandle = CreateFile(
usbFileName,
GENERIC_READ | GENERIC_WRITE,// | GENERIC_WRITE,//读写，或者一起
FILE_SHARE_READ | FILE_SHARE_WRITE,//共享读写，或者一起
0,
OPEN_EXISTING,//必须已经存在
FILE_ATTRIBUTE_NORMAL | FILE_FLAG_OVERLAPPED,
0);
这些参数是针对我的Usb设备，各种调整后达到了能读写、能异步。
2.FileStream参数的坑
_UsbFileStream = new FileStream(new SafeFileHandle(fileHandle, true), FileAccess.ReadWrite, System.Math.Max(caps.OutputReportByteLength, caps.InputReportByteLength), true);
缓冲区大小最终采用 System.Math.Max(caps.OutputReportByteLength, caps.InputReportByteLength)
太小读写错误，大点似乎没关系
3.Write的巨坑
public void Write(byte[] data)
这个data长度必须与缓冲区大写一样，而且数据要从data[1]开始写，如你要写“AB”，
var data=new byte[]{0,(byte)'A',(byte)'B'};
事后发现HIDP_CAPS里面的某个值可能告诉我了。
趟了这些坑后，搞定了，能用线程了^-^，发文纪念。