public static HidDevice FindDevice(int nVid, int nPid, Type oType)
{
string strPath = string.Empty;
string strSearch = string.Format("vid_{0:x4}&pid_{1:x4}", nVid, nPid);
Guid gHid = HIDGuid;
IntPtr hInfoSet = SetupDiGetClassDevs(ref gHid, null, IntPtr.Zero, DIGCF_DEVICEINTERFACE | DIGCF_PRESENT);
try
{
DeviceInterfaceData oInterface = new DeviceInterfaceData();
oInterface.Size = Marshal.SizeOf(oInterface);
int nIndex = 0;
while (SetupDiEnumDeviceInterfaces(hInfoSet, 0, ref gHid, (uint)nIndex, ref oInterface))
{
string strDevicePath = GetDevicePath(hInfoSet, ref oInterface);
if (strDevicePath.IndexOf(strSearch) >= 0)
{
HidDevice oNewDevice = (HidDevice)Activator.CreateInstance(oType);
oNewDevice.Initialise(strDevicePath);
return(oNewDevice);
}
nIndex++;
}
}
catch (Exception ex)
{
throw HidDeviceException.GenerateError(ex.ToString());
}
finally
{
SetupDiDestroyDeviceInfoList(hInfoSet);
}
// No device found.
return(null);
}
private void Initialise(string strPath)
{
m_hHandle = CreateFile(strPath, GENERIC_READ | GENERIC_WRITE, 0, IntPtr.Zero, OPEN_EXISTING, FILE_FLAG_OVERLAPPED, IntPtr.Zero);
if (m_hHandle != InvalidHandleValue || m_hHandle == null)
{
IntPtr lpData;
if (HidD_GetPreparsedData(m_hHandle, out lpData))
{
try
{
HidCaps oCaps;
HidP_GetCaps(lpData, out oCaps);
m_nInputReportLength = oCaps.InputReportByteLength;
m_nOutputReportLength = oCaps.OutputReportByteLength;
m_oFile = new FileStream(new SafeFileHandle(m_hHandle, false), FileAccess.Read | FileAccess.Write, m_nInputReportLength, true);
BeginAsyncRead();
}
catch (Exception)
{
throw HidDeviceException.GenerateWithWinError("Failed to get the detailed data from the hid.");
}
finally
{
HidD_FreePreparsedData(ref lpData);
}
}
else
{
throw HidDeviceException.GenerateWithWinError("GetPreparsedData failed");
}
}
else
{
m_hHandle = IntPtr.Zero;
throw HidDeviceException.GenerateWithWinError("Failed to create device file");
}
}
