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Flashlight
Learn how to use the .NET MAUI IFlashlight interface in the Microsoft.Maui.Devices namespace. This interface provides the ability to turn on or off the device's camera flash, to emulate a flashlight.
10/03/2023
Microsoft.Maui
Microsoft.Maui.Devices

Flashlight

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This article describes how you can use the .NET Multi-platform App UI (.NET MAUI) xref:Microsoft.Maui.Devices.IFlashlight interface. With this interface, you can toggle the device's camera flash on and off, to emulate a flashlight.

The default implementation of the IFlashlight interface is available through the xref:Microsoft.Maui.Devices.Flashlight.Default?displayProperty=nameWithType property. Both the IFlashlight interface and Flashlight class are contained in the Microsoft.Maui.Devices namespace.

Get started

To access the flashlight functionality the following platform-specific setup is required.

Android

There are two permissions to configure in your project: Flashlight and Camera. These permissions can be set in the following ways:

  • Add the assembly-based permission:

    Open the Platforms/Android/MainApplication.cs file and add the following assembly attributes after using directives:

    [assembly: UsesPermission(Android.Manifest.Permission.Flashlight)]
[assembly: UsesPermission(Android.Manifest.Permission.Camera)]

    - or -

  • Update the Android Manifest:

    Open the Platforms/Android/AndroidManifest.xml file and add the following in the manifest node:

    <uses-permission android:name="android.permission.FLASHLIGHT" />
<uses-permission android:name="android.permission.CAMERA" />

    - or -

  • Update the Android Manifest in the manifest editor:

    In Visual Studio double-click on the Platforms/Android/AndroidManifest.xml file to open the Android manifest editor. Then, under Required permissions check the FLASHLIGHT and CAMERA permissions. This will automatically update the AndroidManifest.xml file.

If you set these permissions, Google Play will automatically filter out devices without specific hardware. You can get around this filtering by adding the following assembly attributes to the Platforms/Android/MainApplication.cs file after using directives:

[assembly: UsesFeature("android.hardware.camera", Required = false)]
[assembly: UsesFeature("android.hardware.camera.autofocus", Required = false)]

iOS/Mac Catalyst

No setup is required.

Windows

No setup is required.

Use Flashlight

The flashlight can be turned on and off through the xref:Microsoft.Maui.Devices.IFlashlight.TurnOnAsync and xref:Microsoft.Maui.Devices.IFlashlight.TurnOffAsync methods. The following code example ties the flashlight's on or off state to a xref:Microsoft.Maui.Controls.Switch control:

:::code language="csharp" source="../snippets/shared_1/DeviceDetailsPage.xaml.cs" id="flashlight":::

In addition, the xref:Microsoft.Maui.Devices.Flashlight.IsSupportedAsync%2A method can be invoked to check if a flashlight is available on the device, prior to calling the xref:Microsoft.Maui.Devices.IFlashlight.TurnOnAsync method.

Platform differences

This section describes the platform-specific differences with the flashlight.

Android

The Flashlight class has been optimized based on the device's operating system.

API level 23 and higher

On newer API levels, Torch Mode will be used to turn on or off the flash unit of the device.

API level 22 and lower

A camera surface texture is created to turn on or off the FlashMode of the camera unit.

iOS/Mac Catalyst

The AVCaptureDevice API is used to turn on and off the Torch and Flash mode of the device.

Windows

The xref:Windows.Devices.Lights.Lamp API is used to turn on or off the first detected lamp on the back of the device.