private static IEnumerable <MonitorDeviceEdidInfoNative> EnumerateMonitorEdidDevicesImpl()
{
var info = new Collection <MonitorDeviceEdidInfoNative>();
var GUID_DEVCLASS_MONITOR = GuidDevClass.GUID_DEVCLASS_MONITOR;
var canContinue = true;
while (canContinue)
{
IntPtr devInfo =
SetupApi.NativeMethods.SetupDiGetClassDevsEx(
ref GUID_DEVCLASS_MONITOR, // class GUID
null, // enumerator
IntPtr.Zero, // HWND
SetupApi.DiGetClassFlags.DIGCF_PRESENT, // Flags
IntPtr.Zero, // device info, create a new one
null, // machine name, local machine
IntPtr.Zero);
if (devInfo == IntPtr.Zero)
{
canContinue = false;
}
if (!canContinue)
{
break;
}
for (uint i = 0; Marshal.GetLastWin32Error() != Win32ErrorCode.ERROR_NO_MORE_ITEMS; i++)
{
SetupApi.SP_DEVINFO_DATA devInfoData = SetupApi.SP_DEVINFO_DATA.Empty;
bool deviceInfoSuccess = SetupApi.NativeMethods.SetupDiEnumDeviceInfo(devInfo, i, ref devInfoData);
if (!deviceInfoSuccess)
{
canContinue = false;
}
if (!canContinue)
{
continue;
}
MonitorDeviceEdidInfoNative candidate = GetMonitorDeviceEdidInfo(devInfo, devInfoData);
var canAdd = candidate.IsValid && candidate != MonitorDeviceEdidInfoNative.NoValid;
if (canAdd)
{
info.Add(candidate);
}
}
}
return(info);
}
private static MonitorDeviceEdidInfoNative GetMonitorDeviceEdidInfo(IntPtr devInfo, SetupApi.SP_DEVINFO_DATA devInfoData)
{
uint instanceIdSize = 0;
IntPtr instanceIdSizePointer = Marshal.AllocHGlobal(Marshal.SizeOf(typeof(uint)));
Marshal.StructureToPtr(instanceIdSize, instanceIdSizePointer, false);
var instanceId = new char[256];
bool deviceInstanceSuccess =
SetupApi.NativeMethods.SetupDiGetDeviceInstanceId(
devInfo,
ref devInfoData,
instanceId,
256,
instanceIdSizePointer);
if (!deviceInstanceSuccess)
{
return(MonitorDeviceEdidInfoNative.NoValid);
}
byte[] instanceIdBytes = Encoding.Unicode.GetBytes(instanceId, 0, instanceId.Length);
uint instanceIdSizeValue = ((uint)Marshal.PtrToStructure(instanceIdSizePointer, typeof(uint)) - 1) << 1;
string instanceIdString = Encoding.Unicode.GetString(instanceIdBytes, 0, (int)instanceIdSizeValue);
IntPtr edidRegKey =
SetupApi.NativeMethods.SetupDiOpenDevRegKey(
devInfo,
ref devInfoData,
1, //NativeConstants.DICS_FLAG_GLOBAL,
0,
1, //NativeConstants.DIREG_DEV,
0x20019); //NativeConstants.KEY_READ);
uint edidSize = 128;
var edidData = new byte[edidSize];
uint regQuerySuccess = Registry.NativeMethods.RegQueryValueEx(
edidRegKey,
"EDID",
IntPtr.Zero,
IntPtr.Zero,
edidData,
ref edidSize);
if (regQuerySuccess != Win32ErrorCode.ERROR_SUCCESS)
{
return(MonitorDeviceEdidInfoNative.NoValid);
}
return(new MonitorDeviceEdidInfoNative
{
DeviceId = instanceIdString,
IsValid = !Array.TrueForAll(edidData, y => y == 0),
RawEdid = edidData
});
}
