public static extern Int32 HidP_GetCaps(IntPtr PreparsedData, ref HIDP_CAPS Capabilities);
void Initialize(string devicePathName)
{
DevicePath = devicePathName;
// Get the vendor and product ids out of the path
int startIndex = 0;
startIndex = devicePathName.IndexOf("vid_", 0);
string vendorIDstring = "0x" + devicePathName.Substring(startIndex + 4, 4);
VendorID = Convert.ToInt16(vendorIDstring, 16);
startIndex = devicePathName.IndexOf("pid_", 0);
string productID = "0x" + devicePathName.Substring(startIndex + 4, 4);
ProductID = Convert.ToInt16(productID, 16);
// Try to open up the device
DeviceFileHandle = Kernel32.CreateFile(DevicePath,
(uint)(Kernel32.GENERIC_READ | Kernel32.GENERIC_WRITE),
(uint)0,
(IntPtr)IntPtr.Zero,
(uint)Kernel32.OPEN_EXISTING,
(uint)Kernel32.FILE_FLAG_OVERLAPPED,
(IntPtr)IntPtr.Zero);
//m_oFile = new FileStream(DevicePath,
// FileMode.Open, FileAccess.ReadWrite);
// If we had a problem trying to open the device file handle
// throw an exception
if (DeviceFileHandle.IsInvalid)
{
DeviceFileHandle = null;
return;
//throw HIDDeviceException.GenerateWithWinError("Failed to create device file");
}
// Try to get the device capabilities
IntPtr lpData = new IntPtr(0) ;
if (Hid.HidD_GetPreparsedData(DeviceFileHandle, ref lpData)) // get windows to read the device data into an internal buffer
{
try
{
HIDP_CAPS oCaps = new HIDP_CAPS();
Hid.HidP_GetCaps(lpData, ref oCaps); // extract the device capabilities from the internal buffer
inputReportLength = oCaps.InputReportByteLength; // get the input...
outputReportLength = oCaps.OutputReportByteLength; // ... and output report lengths
//m_oFile = new FileStream(m_hHandle, FileAccess.Read | FileAccess.Write, true, m_nInputReportLength, true);
m_oFile = new FileStream(DeviceFileHandle, FileAccess.Read | FileAccess.Write, inputReportLength, true);
BeginAsyncRead(); // kick off the first asynchronous read
}
catch (Exception ex)
{
throw HIDDeviceException.GenerateWithWinError("Failed to get the detailed data from the hid.");
}
finally
{
Hid.HidD_FreePreparsedData(lpData); // before we quit the funtion, we must free the internal buffer reserved in GetPreparsedData
}
}
else // GetPreparsedData failed? Chuck an exception
{
throw HIDDeviceException.GenerateWithWinError("GetPreparsedData failed");
}
}
public static extern Int32 HidP_GetCaps(IntPtr PreparsedData, ref HIDP_CAPS Capabilities);
