public static bool ReadMultipleReportsFromDevice(ref byte[] inputReportBuffer, int numberOfReports, ref DeviceInformationStructure deviceInformation)
{
var success = false;
var numberOfBytesRead = 0;
long pointerToBuffer = 0;
// Define a temporary buffer for assembling partial data reads into the completed inputReportBuffer
var temporaryBuffer = new Byte[inputReportBuffer.Length];
// Range check the number of reports
if (numberOfReports == 0)
{
Debug.WriteLine(
"usbGenericHidCommunication:readMultipleReportsFromDevice(): -> ERROR: You cannot request 0 reports!");
return false;
}
if (numberOfReports > 128)
{
Debug.WriteLine(
"usbGenericHidCommunication:readMultipleReportsFromDevice(): -> ERROR: Reference application testing does not verify the code for more than 128 reports");
return false;
}
// The size of our inputReportBuffer must be at least the same size as the input report multiplied by the number of reports requested.
if (inputReportBuffer.Length != (deviceInformation.Capabilities.InputReportByteLength * numberOfReports))
{
// inputReportBuffer is not the right length!
Debug.WriteLine(
"usbGenericHidCommunication:readMultipleReportsFromDevice(): -> ERROR: The referenced inputReportBuffer size is incorrect for the number of input reports requested!");
return false;
}
// The readRawReportFromDevice method will fill the passed read buffer or return false
while (pointerToBuffer != (deviceInformation.Capabilities.InputReportByteLength * numberOfReports))
{
Debug.WriteLine(
"usbGenericHidCommunication:readMultipleReportsFromDevice(): -> Reading from device...");
success = ReadRawReportFromDevice(ref temporaryBuffer, ref numberOfBytesRead, ref deviceInformation);
// Was the read successful?
if (!success)
{
return false;
}
// Copy the received data into the referenced input buffer
Array.Copy(temporaryBuffer, 0, inputReportBuffer, pointerToBuffer, numberOfBytesRead);
pointerToBuffer += numberOfBytesRead;
}
return success;
}
public static void QueryDeviceCapabilities(ref DeviceInformationStructure deviceInformation)
{
var preparsedData = new IntPtr();
try
{
// Get the preparsed data from the HID driver
Hid.HidD_GetPreparsedData(deviceInformation.HidHandle, ref preparsedData);
// Get the HID device's capabilities
var result = Hid.HidP_GetCaps(preparsedData, ref deviceInformation.Capabilities);
if ((result == 0)) return;
Debug.WriteLine("usbGenericHidCommunication:queryDeviceCapabilities() -> Device query results:");
Debug.WriteLine("usbGenericHidCommunication:queryDeviceCapabilities() -> Usage: {0}",
Convert.ToString(deviceInformation.Capabilities.Usage, 16));
Debug.WriteLine("usbGenericHidCommunication:queryDeviceCapabilities() -> Usage Page: {0}",
Convert.ToString(deviceInformation.Capabilities.UsagePage, 16));
Debug.WriteLine("usbGenericHidCommunication:queryDeviceCapabilities() -> Input Report Byte Length: {0}",
deviceInformation.Capabilities.InputReportByteLength.ToString(CultureInfo.InvariantCulture));
Debug.WriteLine("usbGenericHidCommunication:queryDeviceCapabilities() -> Output Report Byte Length: {0}",
deviceInformation.Capabilities.OutputReportByteLength.ToString(CultureInfo.InvariantCulture));
Debug.WriteLine("usbGenericHidCommunication:queryDeviceCapabilities() -> Feature Report Byte Length: {0}",
deviceInformation.Capabilities.FeatureReportByteLength.ToString(CultureInfo.InvariantCulture));
Debug.WriteLine("usbGenericHidCommunication:queryDeviceCapabilities() -> Number of Link Collection Nodes: {0}",
deviceInformation.Capabilities.NumberLinkCollectionNodes.ToString(CultureInfo.InvariantCulture));
Debug.WriteLine("usbGenericHidCommunication:queryDeviceCapabilities() -> Number of Input Button Caps: {0}",
deviceInformation.Capabilities.NumberInputButtonCaps.ToString(CultureInfo.InvariantCulture));
Debug.WriteLine("usbGenericHidCommunication:queryDeviceCapabilities() -> Number of Input Value Caps: {0}",
deviceInformation.Capabilities.NumberInputValueCaps.ToString(CultureInfo.InvariantCulture));
Debug.WriteLine("usbGenericHidCommunication:queryDeviceCapabilities() -> Number of Input Data Indices: {0}",
deviceInformation.Capabilities.NumberInputDataIndices.ToString(CultureInfo.InvariantCulture));
Debug.WriteLine("usbGenericHidCommunication:queryDeviceCapabilities() -> Number of Output Button Caps: {0}",
deviceInformation.Capabilities.NumberOutputButtonCaps.ToString(CultureInfo.InvariantCulture));
Debug.WriteLine("usbGenericHidCommunication:queryDeviceCapabilities() -> Number of Output Value Caps: {0}",
deviceInformation.Capabilities.NumberOutputValueCaps.ToString(CultureInfo.InvariantCulture));
Debug.WriteLine("usbGenericHidCommunication:queryDeviceCapabilities() -> Number of Output Data Indices: {0}",
deviceInformation.Capabilities.NumberOutputDataIndices.ToString(CultureInfo.InvariantCulture));
Debug.WriteLine("usbGenericHidCommunication:queryDeviceCapabilities() -> Number of Feature Button Caps: {0}",
deviceInformation.Capabilities.NumberFeatureButtonCaps.ToString(CultureInfo.InvariantCulture));
Debug.WriteLine("usbGenericHidCommunication:queryDeviceCapabilities() -> Number of Feature Value Caps: {0}",
deviceInformation.Capabilities.NumberFeatureValueCaps.ToString(CultureInfo.InvariantCulture));
Debug.WriteLine("usbGenericHidCommunication:queryDeviceCapabilities() -> Number of Feature Data Indices: {0}",
deviceInformation.Capabilities.NumberFeatureDataIndices.ToString(CultureInfo.InvariantCulture));
}
catch (Exception)
{
// Something went badly wrong... this shouldn't happen, so we throw an exception
Debug.WriteLine("usbGenericHidCommunication:queryDeviceCapabilities() -> EXECEPTION: An unrecoverable error has occurred!");
throw;
}
finally
{
// Free up the memory before finishing
if (preparsedData != IntPtr.Zero)
{
Hid.HidD_FreePreparsedData(preparsedData);
}
}
}
public static bool FindTargetDevice(ref DeviceInformationStructure deviceInformation)
{
Debug.WriteLine("usbGenericHidCommunication:findTargetDevice() -> Method called");
var listOfDevicePathNames = new String[128]; // 128 is the maximum number of USB devices allowed on a single host
var numberOfDevicesFound = 0;
try
{
// Reset the device detection flag
var isDeviceDetected = false;
deviceInformation.IsDeviceAttached = false;
// Get all the devices with the correct HID GUID
var deviceFoundByGuid = FindHidDevices(ref listOfDevicePathNames, ref numberOfDevicesFound);
if (deviceFoundByGuid)
{
Debug.WriteLine("usbGenericHidCommunication:findTargetDevice() -> Devices with matching GUID found...");
var listIndex = 0;
do
{
Debug.WriteLine("usbGenericHidCommunication:findTargetDevice() -> Performing CreateFile to listIndex {0}", listIndex.ToString(CultureInfo.InvariantCulture));
deviceInformation.HidHandle = Kernel32.CreateFile(listOfDevicePathNames[listIndex], 0, Constants.FileShareRead | Constants.FileShareWrite, IntPtr.Zero, Constants.OpenExisting, 0, 0);
if (!deviceInformation.HidHandle.IsInvalid)
{
deviceInformation.Attributes.Size = Marshal.SizeOf(deviceInformation.Attributes);
var success = Hid.HidD_GetAttributes(deviceInformation.HidHandle, ref deviceInformation.Attributes);
if (success)
{
Debug.WriteLine(string.Format("usbGenericHidCommunication:findTargetDevice() -> Found device with VID {0}, PID {1} and Version number {2}",
Convert.ToString(deviceInformation.Attributes.VendorID, 16),
Convert.ToString(deviceInformation.Attributes.ProductID, 16),
Convert.ToString(deviceInformation.Attributes.VersionNumber, 16)));
// Do the VID and PID of the device match our target device?
if ((deviceInformation.Attributes.VendorID == deviceInformation.TargetVendorId) &&
(deviceInformation.Attributes.ProductID == deviceInformation.TargetProductId))
{
// Matching device found
Debug.WriteLine("usbGenericHidCommunication:findTargetDevice() -> Device with matching VID and PID found!");
isDeviceDetected = true;
// Store the device's pathname in the device information
deviceInformation.DevicePathName = listOfDevicePathNames[listIndex];
}
else
{
// Wrong device, close the handle
Debug.WriteLine("usbGenericHidCommunication:findTargetDevice() -> Device didn't match... Continuing...");
deviceInformation.HidHandle.Close();
}
}
else
{
// Something went rapidly south... give up!
Debug.WriteLine("usbGenericHidCommunication:findTargetDevice() -> Something bad happened - couldn't fill the HIDD_ATTRIBUTES, giving up!");
deviceInformation.HidHandle.Close();
}
}
// Move to the next device, or quit if there are no more devices to examine
listIndex++;
}
while (!((isDeviceDetected || (listIndex == numberOfDevicesFound + 1))));
}
// If we found a matching device then we need discover more details about the attached device
// and then open read and write handles to the device to allow communication
if (isDeviceDetected)
{
// Query the HID device's capabilities (primarily we are only really interested in the
// input and output report byte lengths as this allows us to validate information sent
// to and from the device does not exceed the devices capabilities.
//
// We could determine the 'type' of HID device here too, but since this class is only
// for generic HID communication we don't care...
QueryDeviceCapabilities(ref deviceInformation);
// Open the readHandle to the device
Debug.WriteLine("usbGenericHidCommunication:findTargetDevice() -> Opening a readHandle to the device");
deviceInformation.ReadHandle = Kernel32.CreateFile(
deviceInformation.DevicePathName,
Constants.GenericRead,
Constants.FileShareRead | Constants.FileShareWrite,
IntPtr.Zero, Constants.OpenExisting,
Constants.FileFlagOverlapped,
0);
// Did we open the readHandle successfully?
if (deviceInformation.ReadHandle.IsInvalid)
{
Debug.WriteLine("usbGenericHidCommunication:findTargetDevice() -> Unable to open a readHandle to the device!");
return false;
}
Debug.WriteLine("usbGenericHidCommunication:findTargetDevice() -> Opening a writeHandle to the device");
deviceInformation.WriteHandle = Kernel32.CreateFile(
deviceInformation.DevicePathName,
Constants.GenericWrite,
Constants.FileShareRead | Constants.FileShareWrite,
IntPtr.Zero,
Constants.OpenExisting, 0, 0);
// Did we open the writeHandle successfully?
if (deviceInformation.WriteHandle.IsInvalid)
{
Debug.WriteLine("usbGenericHidCommunication:findTargetDevice() -> Unable to open a writeHandle to the device!");
// Attempt to close the writeHandle
deviceInformation.WriteHandle.Close();
return false;
}
// Device is now discovered and ready for use, update the status
deviceInformation.IsDeviceAttached = true;
return true;
}
// The device wasn't detected.
Debug.WriteLine("usbGenericHidCommunication:findTargetDevice() -> No matching device found!");
return false;
}
catch (Exception)
{
Debug.WriteLine("usbGenericHidCommunication:findTargetDevice() -> EXCEPTION: Unknown - device not found");
return false;
}
}
public static bool ReadRawReportFromDevice(ref byte[] inputReportBuffer, ref int numberOfBytesRead, ref DeviceInformationStructure deviceInformation)
{
// Make sure a device is attached
if (!deviceInformation.IsDeviceAttached)
{
Debug.WriteLine("usbGenericHidCommunication:readReportFromDevice(): -> No device attached!");
return false;
}
IntPtr eventObject;
var hidOverlapped = new NativeOverlapped();
IntPtr nonManagedBuffer;
IntPtr nonManagedOverlapped;
try
{
// Prepare an event object for the overlapped ReadFile
eventObject = Kernel32.CreateEvent(IntPtr.Zero, false, false, "");
hidOverlapped.OffsetLow = 0;
hidOverlapped.OffsetHigh = 0;
hidOverlapped.EventHandle = eventObject;
// Allocate memory for the unmanaged input buffer and overlap structure.
nonManagedBuffer = Marshal.AllocHGlobal(inputReportBuffer.Length);
nonManagedOverlapped = Marshal.AllocHGlobal(Marshal.SizeOf(hidOverlapped));
Marshal.StructureToPtr(hidOverlapped, nonManagedOverlapped, false);
// Read the input report buffer
Debug.WriteLine("usbGenericHidCommunication:readReportFromDevice(): -> Attempting to ReadFile");
var success = Kernel32.ReadFile(
deviceInformation.ReadHandle,
nonManagedBuffer,
inputReportBuffer.Length,
ref numberOfBytesRead,
nonManagedOverlapped);
if (!success)
{
// We are now waiting for the FileRead to complete
Debug.WriteLine(
"usbGenericHidCommunication:readReportFromDevice(): -> ReadFile started, waiting for completion...");
// Wait a maximum of 3 seconds for the FileRead to complete
var result = Kernel32.WaitForSingleObject(eventObject, 3000);
switch (result)
{
// Has the ReadFile completed successfully?
case Constants.WaitObject0:
// Get the number of bytes transferred
Kernel32.GetOverlappedResult(deviceInformation.ReadHandle, nonManagedOverlapped, ref numberOfBytesRead, false);
Debug.WriteLine("usbGenericHidCommunication:readReportFromDevice(): -> ReadFile successful (overlapped) {0} bytes read", numberOfBytesRead);
break;
// Did the FileRead operation timeout?
case Constants.WaitTimeout:
// Cancel the ReadFile operation
Kernel32.CancelIo(deviceInformation.ReadHandle);
if (!deviceInformation.HidHandle.IsInvalid) deviceInformation.HidHandle.Close();
if (!deviceInformation.ReadHandle.IsInvalid) deviceInformation.ReadHandle.Close();
if (!deviceInformation.WriteHandle.IsInvalid) deviceInformation.WriteHandle.Close();
// Detach the USB device to try to get us back in a known state
//detachUsbDevice();
Debug.WriteLine(
"usbGenericHidCommunication:readReportFromDevice(): -> ReadFile timedout! USB device detached");
return false;
// Some other unspecified error has occurred?
default:
// Cancel the ReadFile operation
// Detach the USB device to try to get us back in a known state
Debug.WriteLine(
"usbGenericHidCommunication:readReportFromDevice(): -> ReadFile unspecified error! USB device detached");
return false;
}
}
// Report receieved correctly, copy the unmanaged input buffer over to the managed buffer
Marshal.Copy(nonManagedBuffer, inputReportBuffer, 0, numberOfBytesRead);
Debug.WriteLine( "usbGenericHidCommunication:readReportFromDevice(): -> ReadFile successful {0} bytes read", numberOfBytesRead);
}
catch (Exception)
{
// An error - send out some debug and return failure
Debug.WriteLine(
"usbGenericHidCommunication:readReportFromDevice(): -> EXCEPTION: When attempting to receive an input report");
return false;
}
// Release non-managed objects before returning
Marshal.FreeHGlobal(nonManagedBuffer);
Marshal.FreeHGlobal(nonManagedOverlapped);
// Close the file handle to release the object
Kernel32.CloseHandle(eventObject);
return true;
}
public static bool WriteRawReportToDevice(byte[] outputReportBuffer, ref DeviceInformationStructure deviceInformation)
{
// Make sure a device is attached
if (!deviceInformation.IsDeviceAttached)
{
Debug.WriteLine("usbGenericHidCommunication:writeReportToDevice(): -> No device attached!");
return false;
}
var numberOfBytesWritten = 0;
try
{
// Set an output report via interrupt to the device
var success = Kernel32.WriteFile(
deviceInformation.WriteHandle,
outputReportBuffer,
outputReportBuffer.Length,
ref numberOfBytesWritten,
IntPtr.Zero);
Debug.WriteLine(success
? "usbGenericHidCommunication:writeReportToDevice(): -> Write report succeeded"
: "usbGenericHidCommunication:writeReportToDevice(): -> Write report failed!");
return success;
}
catch (Exception)
{
// An error - send out some debug and return failure
Debug.WriteLine(
"usbGenericHidCommunication:writeReportToDevice(): -> EXCEPTION: When attempting to send an output report");
return false;
}
}
public static bool ReadSingleReportFromDevice(ref byte[] inputReportBuffer, ref DeviceInformationStructure deviceInformation)
{
var numberOfBytesRead = 0;
// The size of our inputReportBuffer must be at least the same size as the input report.
if (inputReportBuffer.Length != deviceInformation.Capabilities.InputReportByteLength)
{
// inputReportBuffer is not the right length!
Debug.WriteLine(
"usbGenericHidCommunication:readSingleReportFromDevice(): -> ERROR: The referenced inputReportBuffer size is incorrect for the input report size!");
return false;
}
// The readRawReportFromDevice method will fill the passed readBuffer or return false
return ReadRawReportFromDevice(ref inputReportBuffer, ref numberOfBytesRead, ref deviceInformation);
}
public static bool ReadRawReportFromDeviceAsync(ref byte[] inputReportBuffer, ref int numberOfBytesRead, ref DeviceInformationStructure deviceInformation)
{
bool success;
// Make sure a device is attached
if (!deviceInformation.IsDeviceAttached)
{
Debug.WriteLine("usbGenericHidCommunication:readReportFromDevice(): -> No device attached!");
return false;
}
IntPtr eventObject;
var hidOverlapped = new NativeOverlapped();
IntPtr nonManagedBuffer;
IntPtr nonManagedOverlapped;
try
{
// Prepare an event object for the overlapped ReadFile
eventObject = Kernel32.CreateEvent(IntPtr.Zero, false, false, "");
hidOverlapped.OffsetLow = 0;
hidOverlapped.OffsetHigh = 0;
hidOverlapped.EventHandle = eventObject;
// Allocate memory for the unmanaged input buffer and overlap structure.
nonManagedBuffer = Marshal.AllocHGlobal(inputReportBuffer.Length);
nonManagedOverlapped = Marshal.AllocHGlobal(Marshal.SizeOf(hidOverlapped));
Marshal.StructureToPtr(hidOverlapped, nonManagedOverlapped, false);
// Read the input report buffer
success = Kernel32.ReadFile(
deviceInformation.ReadHandle,
nonManagedBuffer,
inputReportBuffer.Length,
ref numberOfBytesRead,
nonManagedOverlapped);
if(success)
Debug.WriteLine("usbGenericHidCommunication:readReportFromDevice(): -> Read Ok");
// Report receieved correctly, copy the unmanaged input buffer over to the managed buffer
Marshal.Copy(nonManagedBuffer, inputReportBuffer, 0, numberOfBytesRead);
}
catch (Exception)
{
// An error - send out some debug and return failure
Debug.WriteLine(
"usbGenericHidCommunication:readReportFromDevice(): -> EXCEPTION: When attempting to receive an input report");
return false;
}
// Release non-managed objects before returning
Marshal.FreeHGlobal(nonManagedBuffer);
Marshal.FreeHGlobal(nonManagedOverlapped);
// Close the file handle to release the object
Kernel32.CloseHandle(eventObject);
return success;
}
