LightSensor.GetCurrentReading | getCurrentReading method

Applies to Windows and Windows Phone

Gets the current ambient-light sensor reading.

Syntax


Public Function GetCurrentReading() As LightSensorReading

Parameters

This method has no parameters.

Return value

Type: LightSensorReading

The current ambient-light sensor reading.

Remarks

An application may use this method to poll the sensor for the current reading as an alternative to registering a ReadingChanged event handler. This would be the preferred alternative for an application that updates its user interface at a specific frame rate. Whether polling once or many times, the application must establish a desired ReportInterval. This informs the sensor driver that resources should be allocated to satisfy subsequent polling requests

Before using the return value from this method, the application must first check that the value is not null. (If the value is null and you attempt to retrieve it, Windows will generate an exception.)

The following example demonstrates how a Windows Store app built with XAML and C# retrieves the current reading for the default light sensor.


private void DisplayCurrentReading(object sender, object args)
{
    LightSensorReading reading = _sensor.GetCurrentReading();
    if (reading != null)
    {
        ScenarioOutput_LUX.Text = String.Format("{0,5:0.00}", reading.IlluminanceInLux);
    }
}


The following example demonstrates how a Windows Store app built for Windows using JavaScript retrieves the current reading for the default light sensor.


function getCurrentReading() {
    var reading = lightSensor.getCurrentReading();
    if (reading) {
        document.getElementById("readingOutputIlluminance").innerHTML = reading.illuminanceInLux.toFixed(2);
    }
}


Requirements

Minimum supported client

Windows 8

Minimum supported server

None supported

Minimum supported phone

Windows Phone 8.1 [Windows Phone Silverlight 8.1 and Windows Runtime apps]

Namespace

Windows.Devices.Sensors
Windows::Devices::Sensors [C++]

Metadata

Windows.winmd

See also

LightSensor

 

 

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