How to use Proximity Sensor (P-Sensor) class in MFC? - c++

Question

I am stuck with the problem when using Proximity Sensor class.
Recently, I have engaged in Proximity Sensor (P-Sensor) software development.
I found some relative reference from Google, e.g. Proximity Sensor class (website: msdn.microsoft.com/en-us/library/windows/apps/windows.devices.sensors.proximitysensor.aspx) and Sample Code (website: github.com/Microsoft/Windows-universal-samples/tree/master/Samples/ProximitySensor/cpp).
I tried to imitate the sample code, but it did not work.
As I know, it is necessary to create runtime api interface at first. The following code is how I create
the interface IProximitySensorStatics and it succeeded. The output prints "0".
The interface IProximitySensorStatics have to be activated by the api GetActivationFactory() before using.
ComPtr<IProximitySensorStatics> stProximitySensorStatics;
HRESULT hr = GetActivationFactory(HStringReference(RuntimeClass_Windows_Devices_Sensors_ProximitySensor).Get(), &stProximitySensorStatics);
printf("CProximitySensorCtrl::GetActivationFactory stProximitySensorStatics hr = %x", hr);
if (FAILED(hr))
{
printf("GetActivationFactory stProximitySensorStatics failed");
return FALSE;
}
The next step is to create the interface IProximitySensor because the runtime api I want to apply is GetCurrentReading() which is the member of IProximitySensor.
Then I use the same method above. The output prints "GetActivationFactory stProximitySensor failed". HRESULT value is 80004002.
If I change HStringReference(RuntimeClass_Windows_Devices_Sensors_ProximitySensor) to HStringReference(RuntimeClass_Windows_Devices_Sensors_ProximitySensorReading), the HRESULT value is 80040154. I do not know how to solve it. HRESULT value list: https://msdn.microsoft.com/en-us/library/cc704587.aspx
ComPtr<IProximitySensor> stProximitySensor;
hr = GetActivationFactory(HStringReference(RuntimeClass_Windows_Devices_Sensors_ProximitySensor).Get(), &stProximitySensor);
printf("CProximitySensorCtrl::GetActivationFactory stProximitySensor hr = %x", hr);
if (FAILED(hr))
{
printf("GetActivationFactory stProximitySensor failed");
return FALSE;
}
Now the problem is that I am wondering how to activate the interface IProximitySensor and even IProximitySensorReading. IProximitySensorReading is another interface which is used to catch the output of GetCurrentReading().
If GetCurrentReading() succeeds to get a value, everything is done.
In other sensor classes such as Accelerometer, Compass, LightSensor, ect, there is always a method GetDefault(). The GetDefault() might solve my problem, but ProximitySensor class does not have this method.
The following code is that I tried to use methods in ProximitySensor class in order to make it work. The hr prints "0", but the output "stProximitySensor" is NULL.
HSTRING m_hsString;
hr = stProximitySensorStatics->GetDeviceSelector(&m_hsString);
hr = stProximitySensorStatics->FromId(m_hsString, &stProximitySensor);
printf("FromId hr = %x", hr);
if (FAILED(hr))
{
printf("FromId failed");
return FALSE;
}
if (stProximitySensor == NULL)
{
printf("FromId stProximitySensor = null failed");
return FALSE;
}
Fully thanks in advance.