/// <summary>
/// Retrieves the GUID of the stylus property associated with the usage page and usage ids
/// within the HID specification.
/// </summary>
/// <param name="page">The usage page id of the HID specification</param>
/// <param name="usage">The usage id of the HID specification</param>
/// <returns>
/// If known, the GUID associated with the usagePageId and usageId.
/// If not known, GUID.Empty
/// </returns>
internal static Guid GetKnownGuid(HidUsagePage page, HidUsage usage)
{
Guid result = Guid.Empty;
Dictionary <HidUsage, Guid> pageMap = null;
if (_hidToGuidMap.TryGetValue(page, out pageMap))
{
pageMap.TryGetValue(usage, out result);
}
return(result);
}
protected override void ParseHw()
{
base.ParseHw();
string[] v;
// this is how we determine the HID class of the device. I've found this to be a very reliable method.
foreach (string hw in _HardwareIds)
{
int i = hw.IndexOf("HID_DEVICE_UP:");
if (i >= 0)
{
v = TextTools.Split(hw.Substring(i), ":");
if (v.Length > 1)
{
ushort hp;
if (ushort.TryParse(v[1].Replace("_U", ""), System.Globalization.NumberStyles.AllowHexSpecifier, System.Globalization.CultureInfo.CurrentCulture.NumberFormat, out hp))
{
_HidPage = (HidUsagePage)(hp);
if ((int)_HidPage > 0xFF)
{
_HidPage = HidUsagePage.Reserved;
if (v.Length > 2)
{
if (ushort.TryParse(v[1].Replace("_U", ""), System.Globalization.NumberStyles.AllowHexSpecifier, System.Globalization.CultureInfo.CurrentCulture.NumberFormat, out hp))
{
_HidPage = (HidUsagePage)(hp);
if ((int)_HidPage > 0xFF)
{
_HidPage = HidUsagePage.Reserved;
}
}
}
return;
}
else
{
return;
}
}
}
}
}
}
/// <summary>
/// Enumerates all HID devices in a specific HID class.
/// </summary>
/// <param name="u">The HID usage page type devices to return.</param>
/// <returns>An array of HidDeviceInfo objects.</returns>
/// <remarks></remarks>
public static HidDeviceInfo[] HidDevicesByUsage(HidUsagePage u)
{
var devs = DeviceEnum.EnumerateDevices <HidDeviceInfo>(DevProp.GUID_DEVINTERFACE_HID);
HidDeviceInfo[] devOut = null;
int c = 0;
foreach (var blurb in devs)
{
if (blurb.HidUsagePage == u || u == HidUsagePage.Undefined)
{
Array.Resize(ref devOut, c + 1);
devOut[c] = blurb;
c += 1;
}
}
return(devOut);
}
