我发现许多类似的已发布问题都涉及管道，但使用重叠 I/O 的方法相同。
我还在网络Peter's blog: Getting a handle on usbprint.sys 上找到了以下文章，该文章提供了有关如何查找 USB 连接设备的 USB 路径名的代码和说明。我在下面的课程中使用了一些代码示例。
我还在 codeproject.com 上找到了 Chuan-Liang Teng 的文章Enumerating windows device，其中包含枚举连接的 USB 设备并询问有关设备的各种设置和详细信息的示例。那篇文章中的代码虽然很旧，但对于这个特定的应用程序来说虽然不是必需的，但很有帮助。
我有一个使用重叠 I/O 的原型 C++ 类，它似乎正在复制使用 USB 连接到热敏打印机的串行端口连接所看到的行为。完整的源代码和 Visual Studio 2017 解决方案和项目文件位于我的 GitHub 存储库 https://github.com/RichardChambers/utilities_tools/tree/main/UsbWindows，因为此片段包含最相关的部分。
我已经在销售点应用程序中使用修改后的代码进行了一个简单的测试，现在正在将其集成到现有的热敏收据打印机源代码中，该源代码已经与串行端口一起使用。
#include <windows.h>
#include <setupapi.h>
#include <initguid.h>
#include <iostream>
// This is the GUID for the USB device class.
// It is defined in the include file Usbiodef.h of the Microsoft Windows Driver Kit.
// See also https://msdn.microsoft.com/en-us/library/windows/hardware/ff545972(v=vs.85).aspx which
// provides basic documentation on this GUID.
DEFINE_GUID(GUID_DEVINTERFACE_USB_DEVICE, 0xA5DCBF10L, 0x6530, 0x11D2, 0x90, 0x1F, 0x00, 0xC0, 0x4F, 0xB9, 0x51, 0xED);
class UsbSerialDevice
{
public:
// See https://docs.microsoft.com/en-us/windows/win32/ipc/named-pipe-server-using-overlapped-i-o?redirectedfrom=MSDN
// to implement time outs for Write and for Read.
UsbSerialDevice(const wchar_t* wszVendorIdIn = nullptr);
~UsbSerialDevice();
int CreateEndPoint(const wchar_t* wszVendorId = nullptr, DWORD dwDesiredAccess = (GENERIC_READ | GENERIC_WRITE));
void CloseEndPoint(void);
int ListEndPoint(const wchar_t* wszVendorIdIn);
int ReadStream(void* bString, size_t nBytes);
int WriteStream(void* bString, size_t nBytes);
DWORD SetWriteTimeOut(DWORD msTimeout);
DWORD SetReadTimeOut(DWORD msTimeout);
DWORD m_dwError; // GetLastError() for last action
DWORD m_dwErrorWrite; // GetLastError() for last write
DWORD m_dwErrorRead; // GetLastError() for last read
DWORD m_dwBytesWritten; // number of bytes last write
DWORD m_dwBytesRead; // number of bytes last read
DWORD m_dwWait; // WaitForSingleObject() return value
private:
HANDLE m_hFile;
OVERLAPPED m_oOverlap;
COMMTIMEOUTS m_timeOut;
const unsigned short m_idLen = 255;
wchar_t m_wszVendorId[255 + 1] = { 0 };
};
UsbSerialDevice::UsbSerialDevice(const wchar_t* wszVendorIdIn) :
m_dwError(0),
m_dwErrorWrite(0),
m_dwErrorRead(0),
m_dwBytesWritten(0),
m_dwBytesRead(0),
m_dwWait(0),
m_hFile(INVALID_HANDLE_VALUE)
{
memset(&m_oOverlap, 0, sizeof(m_oOverlap));
m_oOverlap.hEvent = INVALID_HANDLE_VALUE;
if (wszVendorIdIn != nullptr) ListEndPoint(wszVendorIdIn);
}
void UsbSerialDevice::CloseEndPoint(void )
{
if (m_hFile && m_hFile != INVALID_HANDLE_VALUE) CloseHandle(m_hFile);
if (m_oOverlap.hEvent && m_oOverlap.hEvent != INVALID_HANDLE_VALUE) CloseHandle(m_oOverlap.hEvent);
}
UsbSerialDevice::~UsbSerialDevice()
{
CloseEndPoint();
}
/*
* Returns: -1 - file handle is invalid
* 0 - write failed. See m_dwErrorWrite for GetLastError() value
* 1 - write succedded.
*/
int UsbSerialDevice::WriteStream(void* bString, size_t nBytes)
{
SetLastError(0);
m_dwError = m_dwErrorWrite = 0;
m_dwBytesWritten = 0;
m_dwWait = WAIT_FAILED;
if (m_hFile && m_hFile != INVALID_HANDLE_VALUE) {
BOOL bWrite = WriteFile(m_hFile, bString, nBytes, 0, &m_oOverlap);
m_dwError = m_dwErrorWrite = GetLastError();
if (!bWrite && m_dwError == ERROR_IO_PENDING) {
SetLastError(0);
m_dwError = m_dwErrorWrite = 0;
m_dwWait = WaitForSingleObject(m_oOverlap.hEvent, m_timeOut.WriteTotalTimeoutConstant);
BOOL bCancel = FALSE;
switch (m_dwWait) {
case WAIT_OBJECT_0: // The state of the specified object is signaled.
break;
case WAIT_FAILED: // The function has failed. To get extended error information, call GetLastError.
m_dwError = m_dwErrorWrite = GetLastError();
bCancel = CancelIo(m_hFile);
break;
case WAIT_TIMEOUT: // The time-out interval elapsed, and the object's state is nonsignaled.
case WAIT_ABANDONED: // thread owning mutex terminated before releasing or signaling object.
bCancel = CancelIo(m_hFile);
m_dwError = m_dwErrorRead = ERROR_COUNTER_TIMEOUT;
break;
}
bWrite = GetOverlappedResult(m_hFile, &m_oOverlap, &m_dwBytesRead, FALSE);
}
return bWrite; // 0 or FALSE if failed, 1 or TRUE if succeeded.
}
return -1;
}
/*
* Returns: -1 - file handle is invalid
* 0 - read failed. See m_dwErrorRead for GetLastError() value
* 1 - read succedded.
*/
int UsbSerialDevice::ReadStream(void* bString, size_t nBytes)
{
SetLastError(0);
m_dwError = m_dwErrorRead = 0;
m_dwBytesRead = 0;
m_dwWait = WAIT_FAILED;
if (m_hFile && m_hFile != INVALID_HANDLE_VALUE) {
BOOL bRead = ReadFile(m_hFile, bString, nBytes, &m_dwBytesRead, &m_oOverlap);
m_dwError = m_dwErrorRead = GetLastError();
if (!bRead && m_dwError == ERROR_IO_PENDING) {
SetLastError(0);
m_dwError = m_dwErrorRead = 0;
m_dwWait = WaitForSingleObject(m_oOverlap.hEvent, m_timeOut.ReadTotalTimeoutConstant);
BOOL bCancel = FALSE;
switch (m_dwWait) {
case WAIT_OBJECT_0: // The state of the specified object is signaled.
break;
case WAIT_FAILED: // The function has failed. To get extended error information, call GetLastError.
m_dwError = m_dwErrorWrite = GetLastError();
bCancel = CancelIo(m_hFile);
break;
case WAIT_TIMEOUT: // The time-out interval elapsed, and the object's state is nonsignaled.
case WAIT_ABANDONED: // thread owning mutex terminated before releasing or signaling object.
bCancel = CancelIo(m_hFile);
m_dwError = m_dwErrorRead = ERROR_COUNTER_TIMEOUT;
break;
}
bRead = GetOverlappedResult(m_hFile, &m_oOverlap, &m_dwBytesRead, FALSE);
}
return bRead; // 0 or FALSE if failed, 1 or TRUE if succeeded.
}
return -1;
}
int UsbSerialDevice::ListEndPoint(const wchar_t* wszVendorIdIn)
{
m_dwError = ERROR_INVALID_HANDLE;
if (wszVendorIdIn == nullptr) return 0;
HDEVINFO hDevInfo;
// we need to make sure the vendor and product id codes are in lower case
// as this is needed for the CreateFile() function to open the connection
// to the USB device correctly. this lower case conversion applies to
// any alphabetic characters in the identifier.
//
// for example "VID_0FE6&PID_811E" must be converted to "vid_0fe6&pid_811e"
wchar_t wszVendorId[256] = { 0 };
for (unsigned short i = 0; i < 255 && (wszVendorId[i] = towlower(wszVendorIdIn[i])); i++);
// We will try to get device information set for all USB devices that have a
// device interface and are currently present on the system (plugged in).
hDevInfo = SetupDiGetClassDevs(&GUID_DEVINTERFACE_USB_DEVICE, NULL, 0, DIGCF_DEVICEINTERFACE | DIGCF_PRESENT);
if (hDevInfo != INVALID_HANDLE_VALUE)
{
DWORD dwMemberIdx;
BOOL bContinue = TRUE;
SP_DEVICE_INTERFACE_DATA DevIntfData;
// Prepare to enumerate all device interfaces for the device information
// set that we retrieved with SetupDiGetClassDevs(..)
DevIntfData.cbSize = sizeof(SP_DEVICE_INTERFACE_DATA);
dwMemberIdx = 0;
// Next, we will keep calling this SetupDiEnumDeviceInterfaces(..) until this
// function causes GetLastError() to return ERROR_NO_MORE_ITEMS. With each
// call the dwMemberIdx value needs to be incremented to retrieve the next
// device interface information.
for (BOOL bContinue = TRUE; bContinue; ) {
PSP_DEVICE_INTERFACE_DETAIL_DATA DevIntfDetailData;
SP_DEVINFO_DATA DevData;
DWORD dwSize;
dwMemberIdx++;
SetupDiEnumDeviceInterfaces(hDevInfo, NULL, &GUID_DEVINTERFACE_USB_DEVICE, dwMemberIdx, &DevIntfData);
if (GetLastError() == ERROR_NO_MORE_ITEMS) break;
// As a last step we will need to get some more details for each
// of device interface information we are able to retrieve. This
// device interface detail gives us the information we need to identify
// the device (VID/PID), and decide if it's useful to us. It will also
// provide a DEVINFO_DATA structure which we can use to know the serial
// port name for a virtual com port.
DevData.cbSize = sizeof(DevData);
// Get the required buffer size. Call SetupDiGetDeviceInterfaceDetail with
// a NULL DevIntfDetailData pointer, a DevIntfDetailDataSize
// of zero, and a valid RequiredSize variable. In response to such a call,
// this function returns the required buffer size at dwSize.
SetupDiGetDeviceInterfaceDetail(hDevInfo, &DevIntfData, NULL, 0, &dwSize, NULL);
// Allocate memory for the DeviceInterfaceDetail struct. Don't forget to
// deallocate it later!
DevIntfDetailData = (PSP_DEVICE_INTERFACE_DETAIL_DATA)HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, dwSize);
DevIntfDetailData->cbSize = sizeof(SP_DEVICE_INTERFACE_DETAIL_DATA);
if (SetupDiGetDeviceInterfaceDetail(hDevInfo, &DevIntfData, DevIntfDetailData, dwSize, &dwSize, &DevData))
{
if (wcsstr(DevIntfDetailData->DevicePath, wszVendorId)) {
wcscpy_s(m_wszVendorId, DevIntfDetailData->DevicePath);
}
}
HeapFree(GetProcessHeap(), 0, DevIntfDetailData);
}
SetupDiDestroyDeviceInfoList(hDevInfo);
}
return 0;
}
int UsbSerialDevice::CreateEndPoint(const wchar_t* wszVendorIdIn, DWORD dwDesiredAccess)
{
if (wszVendorIdIn) {
ListEndPoint(wszVendorIdIn);
}
m_dwError = ERROR_INVALID_HANDLE;
// Finally we can start checking if we've found a useable device,
// by inspecting the DevIntfDetailData->DevicePath variable.
//
// The DevicePath looks something like this for a Brecknell 67xx Series Serial Scale
// \\?\usb#vid_1a86&pid_7523#6&28eaabda&0&2#{a5dcbf10-6530-11d2-901f-00c04fb951ed}
//
// The VID for a particular vendor will be the same for a particular vendor's equipment.
// The PID is variable for each device of the vendor.
//
// As you can see it contains the VID/PID for the device, so we can check
// for the right VID/PID with string handling routines.
// See https://github.com/Microsoft/Windows-driver-samples/blob/master/usb/usbview/vndrlist.h
// See https://blog.peter.skarpetis.com/archives/2005/04/07/getting-a-handle-on-usbprintsys/
// which describes a sample USB thermal receipt printer test application.
SetLastError(0);
m_hFile = CreateFile(m_wszVendorId, dwDesiredAccess, FILE_SHARE_READ | FILE_SHARE_WRITE, 0, OPEN_ALWAYS, FILE_FLAG_OVERLAPPED, 0);
if (m_hFile == INVALID_HANDLE_VALUE) {
m_dwError = GetLastError();
// wprintf(_T(" CreateFile() failed. GetLastError() = %d\n"), m_dwError);
}
else {
m_oOverlap.hEvent = CreateEvent(
NULL, // default security attribute
TRUE, // manual-reset event
TRUE, // initial state = signaled
NULL); // unnamed event object
m_timeOut.ReadIntervalTimeout = 0;
m_timeOut.ReadTotalTimeoutMultiplier = 0;
m_timeOut.ReadTotalTimeoutConstant = 5000;
m_timeOut.WriteTotalTimeoutMultiplier = 0;
m_timeOut.WriteTotalTimeoutConstant = 5000;
m_dwError = 0; // GetLastError();
return 1;
}
return 0;
}