/// <summary>
/// Gets the key filtering info of the active device.
/// </summary>
/// <returns></returns>
public KeyFiltering KeyboardGetKeyFiltering()
{
KeyFiltering filterRequest;
int outputSize = 2 * sizeof(ushort);
byte[] outputBuffer = new byte[outputSize];
if (!DeviceIoControl(_driverHandle, IOCTL_KEYBOARD_GET_FILTER, IntPtr.Zero, 0, outputBuffer, (uint)outputSize, out uint bytesReturned, IntPtr.Zero))
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
if (bytesReturned < 2 * sizeof(ushort))
{
throw new Exception("Invalid query result from the driver.");
}
filterRequest = KeyFiltering.FromBuffer(outputBuffer);
if (filterRequest.FilterMode == FilterMode.KEY_FLAG_AND_SCANCODE && filterRequest.FlagOrCount > 0)
{
outputSize += filterRequest.FlagOrCount * Marshal.SizeOf(typeof(KeyFilterData));
outputBuffer = new byte[outputSize];
if (!DeviceIoControl(_driverHandle, IOCTL_KEYBOARD_GET_FILTER, IntPtr.Zero, 0, outputBuffer, (uint)outputSize, out bytesReturned, IntPtr.Zero))
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
filterRequest = KeyFiltering.FromBuffer(outputBuffer);
}
return(filterRequest);
}
internal static KeyFiltering FromBuffer(byte[] buffer)
{
KeyFiltering filterRequest = new KeyFiltering();
int bytesRead = 0;
int bytesRemained = buffer.Length;
if (bytesRemained >= sizeof(ushort))
{
filterRequest.FilterMode = (FilterMode)BitConverter.ToUInt16(buffer, bytesRead);
bytesRead += sizeof(ushort);
bytesRemained -= sizeof(ushort);
if (bytesRemained >= sizeof(ushort))
{
filterRequest.FlagOrCount = BitConverter.ToUInt16(buffer, bytesRead);
bytesRead += sizeof(ushort);
bytesRemained -= sizeof(ushort);
if (filterRequest.FilterMode == FilterMode.KEY_FLAG_AND_SCANCODE && bytesRemained >= filterRequest.FlagOrCount * 2 * sizeof(ushort))
{
filterRequest.FilterData = new KeyFilterData[filterRequest.FlagOrCount];
for (int i = 0; i < filterRequest.FlagOrCount; i++)
{
filterRequest.FilterData[i].KeyFlagPredicates = (KeyboardKeyFlag)BitConverter.ToUInt16(buffer, bytesRead);
bytesRead += sizeof(ushort);
filterRequest.FilterData[i].ScanCode = BitConverter.ToUInt16(buffer, bytesRead);
bytesRead += sizeof(ushort);
}
}
}
}
return(filterRequest);
}
/// <summary>
/// Sets the key filtering for the currently active device.
/// </summary>
/// <param name="filterRequest">Structure that contains the key filtering data.</param>
public void KeyboardSetFiltering(KeyFiltering filterRequest)
{
if (filterRequest.FilterMode == FilterMode.KEY_NONE || filterRequest.FilterMode == FilterMode.KEY_ALL)
{
ushort filterMode = (ushort)filterRequest.FilterMode;
if (!DeviceIoControl(_driverHandle, IOCTL_KEYBOARD_SET_FILTER, ref filterMode, sizeof(ushort), IntPtr.Zero, 0, out uint bytesReturned, IntPtr.Zero))
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
}
else
{
filterRequest.RemoveRedundant();
var request = filterRequest.GetBytes();
if (!DeviceIoControl(_driverHandle, IOCTL_KEYBOARD_SET_FILTER, request, (uint)request.Length, IntPtr.Zero, 0, out uint bytesReturned, IntPtr.Zero))
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
}
}
