ILocationReport::GetValue method (locationapi.h)

[The Win32 Location API is available for use in the operating systems specified in the Requirements section. It may be altered or unavailable in subsequent versions. Instead, use the Windows.Devices.Geolocation API. ]

Retrieves a property value from the location report.

Syntax

HRESULT GetValue(
  [in]  REFPROPERTYKEY pKey,
  [out] PROPVARIANT    *pValue
);

Parameters

[in] pKey

REFPROPERTYKEY that specifies the name of the property to retrieve.

[out] pValue

Address of a PROPVARIANT that receives the property value.

Return value

If this method succeeds, it returns S_OK. Otherwise, it returns an HRESULT error code.

Remarks

The properties may be platform defined or manufacturer defined.

Platform-defined PROPERTYKEY values for location sensors are defined in the location sensor data types section of sensors.h.

The following is a table of some platform-defined properties that are commonly association with location reports. These property keys have a fmtid field equal to SENSOR_DATA_TYPE_LOCATION_GUID. Additional properties can be found in sensors.h. If you are implementing your own location report to pass to SetReport, this table indicates which values must be supplied in your report object's implementation of GetValue.

The following is a table of other platform-defined properties that may occur in location reports but are not specific to location. The fmtid field of these property keys is SENSOR_PROPERTY_COMMON_GUID.

Examples

The following example demonstrates how to call GetValue to get a property value. You must include sensors.h to use the constant in the example.

PROPVARIANT pv;				
HRESULT hr = spLatLongReport->GetValue(SENSOR_DATA_TYPE_LATITUDE_DEGREES, &pv);

The following example shows how to implement GetValue in your own report object. This implementation allows the caller to get values for several location report fields. This code requires you to include sensors.h and provarutil.h.

STDMETHODIMP CLocationReport::GetValue(REFPROPERTYKEY pKey, PROPVARIANT *pValue)
{
    HRESULT hr = S_OK;

    if (pKey.fmtid == SENSOR_DATA_TYPE_LOCATION_GUID) 
    {
        // properties for civic address reports
        if (pKey.pid == SENSOR_DATA_TYPE_ADDRESS1.pid)
        {
            hr = InitPropVariantFromString(m_address1, pValue);
        } 
        else if (pKey.pid == SENSOR_DATA_TYPE_ADDRESS2.pid)
        {    
            hr = InitPropVariantFromString(m_address2, pValue);
        }
        else if (pKey.pid == SENSOR_DATA_TYPE_CITY.pid)
        {
            hr = InitPropVariantFromString(m_city, pValue);
        }
        else if (pKey.pid == SENSOR_DATA_TYPE_STATE_PROVINCE.pid)
        {
            hr = InitPropVariantFromString(m_stateprovince, pValue);
        } 
        else if (pKey.pid == SENSOR_DATA_TYPE_POSTALCODE.pid)
        {
            hr = InitPropVariantFromString(m_postalcode, pValue);
        }
        else if (pKey.pid == SENSOR_DATA_TYPE_COUNTRY_REGION.pid)    
        {
            hr = InitPropVariantFromString(m_countryregion, pValue);
        }
        // properties for latitude/longitude reports
        else if (pKey.pid == SENSOR_DATA_TYPE_LATITUDE_DEGREES.pid)
        {
            hr = InitPropVariantFromDouble(m_latitude, pValue);
        } 
        else if (pKey.pid == SENSOR_DATA_TYPE_LONGITUDE_DEGREES.pid)
        {
            hr = InitPropVariantFromDouble(m_longitude, pValue);
        }
        else if (pKey.pid == SENSOR_DATA_TYPE_ERROR_RADIUS_METERS.pid)    
        {
            hr = InitPropVariantFromDouble(m_errorradius, pValue);
        }
        else 
        {
            hr = HRESULT_FROM_WIN32(ERROR_NO_DATA);
            PropVariantInit(pValue);
        }
    }
    return hr;
}

Requirements

See also

ILocationReport