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ISensorClassExtension::PostStateChange method (sensorsclassextension.h)

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The ISensorClassExtension::PostStateChange method notifies the sensor class extension about a change in the operational state of the sensor.

Syntax

HRESULT PostStateChange(
  [in] LPWSTR      pwszSensorID,
  [in] SensorState state
);

Parameters

[in] pwszSensorID

LPWSTR that contains the ID for the sensor for which the driver is raising the event.

[in] state

SensorState value that indicates the new state.

Return value

This method returns an HRESULT. Possible values include, but are not limited to, one of the following values.

Return code Description
S_OK The method succeeded.
E_POINTER A required pointer argument was NULL.
HRESULT_FROM_WIN32(ERROR_CAN_NOT_COMPLETE) The class extension is not initialized.

Remarks

Sensor state information is also available through the SENSOR_PROPERTY_STATE property key.

Examples

The following example code demonstrates a function that posts a state-changed event.

HRESULT PostStateEvent()
{
    // Validate that we have a pointer to the class extension.
    HRESULT hr = (NULL == m_spSensorCXT) ? E_UNEXPECTED : S_OK ;

    if (SUCCEEDED(hr))
    {
        SensorState st;

        // Retrieve the sensor state
        hr = m_pDdi->GetSensorState(&st);

        if (SUCCEEDED(hr))
        {
            // Post the state change event.
            hr = m_spSensorCXT->PostStateChange(g_wszSensorID, st);
        }
    }

    return hr;
}

Requirements

Requirement Value
Minimum supported client Windows 7,Available in Windows 7.
Minimum supported server None supported
Target Platform Desktop
Header sensorsclassextension.h
Library SensorsClassExtension.lib

See also