LightSensor.ReadingChanged 事件

定義

命名空間:

Windows.Devices.Sensors

每次環境光線感應器報告新的感應器讀數時發生。

// Register
event_token ReadingChanged(TypedEventHandler<LightSensor, LightSensorReadingChangedEventArgs const&> const& handler) const;

// Revoke with event_token
void ReadingChanged(event_token const* cookie) const;

// Revoke with event_revoker
LightSensor::ReadingChanged_revoker ReadingChanged(auto_revoke_t, TypedEventHandler<LightSensor, LightSensorReadingChangedEventArgs const&> const& handler) const;

public event TypedEventHandler<LightSensor,LightSensorReadingChangedEventArgs> ReadingChanged;

function onReadingChanged(eventArgs) { /* Your code */ }
lightSensor.addEventListener("readingchanged", onReadingChanged);
lightSensor.removeEventListener("readingchanged", onReadingChanged);
- or -
lightSensor.onreadingchanged = onReadingChanged;

Public Custom Event ReadingChanged As TypedEventHandler(Of LightSensor, LightSensorReadingChangedEventArgs) 

事件類型

TypedEventHandler<LightSensor,LightSensorReadingChangedEventArgs>

範例

下列範例示範如何使用 C# 和 XAML 建置的 UWP 應用程式註冊其 ReadingChanged 事件處理常式。

private void ScenarioEnable(object sender, RoutedEventArgs e)
{
    if (_sensor != null)
    {
        // Establish the report interval
        _sensor.ReportInterval = _desiredReportInterval;

        Window.Current.VisibilityChanged += new WindowVisibilityChangedEventHandler(VisibilityChanged);
        _sensor.ReadingChanged += new TypedEventHandler<LightSensor, LightSensorReadingChangedEventArgs>(ReadingChanged);

        ScenarioEnableButton.IsEnabled = false;
        ScenarioDisableButton.IsEnabled = true;
    }
    else
    {
        rootPage.NotifyUser("No light sensor found", NotifyType.StatusMessage);
    }
}

下列範例顯示 ReadingChanged 事件處理常式。

async private void ReadingChanged(object sender, LightSensorReadingChangedEventArgs e)
{
    await Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
    {
        LightSensorReading reading = e.Reading;
        ScenarioOutput_LUX.Text = String.Format("{0,5:0.00}", reading.IlluminanceInLux);
    });
}

備註

應用程式可以註冊此事件處理常式以取得感應器讀數。 應用程式必須建立所需的 ReportInterval。 這會通知感應器驅動程式應該配置資源以滿足應用程式的需求。

應用程式可以藉由設定 ReportInterval 屬性來設定此事件的頻率。