DotNet MAUI notes

Exploring Camera Features in .NET MAUI with CommunityToolkit.Maui.Camera

The.NET Multiplatform App UI (.NET MAUI) has been the new version of Xamarin.Forms that it aims to offer a single project system and the opportunity to develop a natively UI application for Windows, macOS, iOS, and Android. Battery management controls such as charging, discharging, power alerts or even controlling the use of the back camera that is used in taking pictures, scanning barcode, and implementing the augmented reality.

For the convenience of integrating the camera into.NET MAUI applications, what’s provided by the CommunityToolkit.Maui.Camera NuGet package can be as follows. This toolkit makes use of .NET MAUI by building upon it and providing efficient interfaces and methods that allow for the usage of the camera without having to deal with the specifics of the target operating system.

The next part of the article will focus on camera capabilities that can be used in.NET MAUI with the help of the CommunityToolkit.Maui.Camera package. You will also learn how to allow access to front and/or back camera, and provide real examples to make Zoom in and out operations and to control flashlight.

Camera Features in MAUI

An interface that has built in compatibility with camera features is crucial and makes the production of comprehensive and evocative applications possible. Specifically, the CommunityToolkit.Maui.Camera package offers a high level of introspection of the native camera APIs, so that developers can easily integrate camera features.

Among the basic components to be implemented is the possibility to take pictures and make videos with the help of a camera of the device. It makes this task much easier by offering asynchronous methods that cover the initialization, display and disposal of the camera resources.

Example

To get started, first install the CommunityToolkit.Maui.Camera NuGet package in your MAUI project:

dotnet add package CommunityToolkit.Maui.Camera

Second, for permissions you need to check that all the required permission sets are present at your project. For Android, update the AndroidManifest.xml:

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

For iOS, add the following to your Info.plist:

<key>NSCameraUsageDescription</key>
<string>This app requires camera access to take photos.</string>

Now, you can use the camera in your code:

using CommunityToolkit.Maui.Camera;

public async Task CapturePhotoAsync()
{
    var photo = await CameraService.CapturePhotoAsync();
    if (photo != null)
    {
        // Use the photo (e.g., display it in the UI or save it)
    }
}

Front Camera in MAUI

It is crucial for applications which includes user selfies or video conference the front camera should be accessible. This means that there is a package called CommunityToolkit.Maui.Camera which enables one to define which camera to use in capturing picture or shooting videos.

Example
To access the front camera, modify the capture settings to specify the camera option:

public async Task CaptureSelfieAsync()
{
    var captureOptions = new CameraCaptureOptions
    {
        CameraOption = CameraOption.Front
    };

    var photo = await CameraService.CapturePhotoAsync(captureOptions);
    if (photo != null)
    {
        // Process the selfie photo
    }
}

Here we create a CameraCaptureOptions object setting CameraOption to Front. This tells the CameraService to take the photo with the front facing camera.

Back Camera in MAUI

With the back camera typically being used to capture scenes, scan documents etc., or augmented reality applications. Like with a front camera, you can use the back camera from your capture settings.

Example
Here’s how you can capture a photo using the back camera:

public async Task CaptureSceneAsync()
{
    var captureOptions = new CameraCaptureOptions
    {
        CameraOption = CameraOption.Back
    };

    var photo = await CameraService.CapturePhotoAsync(captureOptions);
    if (photo != null)
    {
        // Handle the captured scene
    }
}

The CameraService then configures the CameraOption to Back and so it uses the rear camera of the device and you can hence take high quality images of the environment.

Zoom Feature in MAUI

Zoom functionality adds to the functionality of the camera giving people the ability to focus on the distant objects without being physical close. Zooming is implemented by adjusting the camera’s zoom level, that’s available through toolkit’s APIs.

Example
To implement zoom, you can adjust the zoom level before or during the camera preview:

public async Task ZoomCameraAsync(double zoomLevel)
{
    var captureOptions = new CameraCaptureOptions
    {
        CameraOption = CameraOption.Back,
        Zoom = zoomLevel
    };

    var photo = await CameraService.CapturePhotoAsync(captureOptions);
    if (photo != null)
    {
        // Process the zoomed photo
    }
}

In this example, we set Zoom property in CameraCaptureOptions. This zoomLevel must be in the range of minimum and maximum zoom levels supported by the device camera.

If you want to dynamically control the zoom while you’re previewing, then you may want to create a custom camera preview control and handle user input and zoom with the toolkits APIs to reflect input accordingly.

Flashlight in MAUI

For low light photography, or even as a utility feature in an application; controlling the flashlight (torch) needs to be a priority. The CommunityToolkit.Maui.Camera has simple methods to turn on flashlight.

Example
Here’s how you can control the flashlight:

public async Task ToggleFlashlightAsync(bool turnOn)
{
    if (turnOn)
    {
        await FlashlightService.TurnOnAsync();
    }
    else
    {
        await FlashlightService.TurnOffAsync();
    }
}

For this example, we use FlashlightService to turn the flashlight on or off asynchronously. Ensure that you have the necessary permissions in your project:

For Android AndroidManifest.xml:

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

For iOS Info.plist:

<key>NSCameraUsageDescription</key>
<string>This app requires camera access to use the flashlight.</string>

Combining these methods can add to your application’s Camera functionality, which is a lot more immersive.

Conclusion

CommunityToolkit.Maui.Camera package makes life easy by providing camera features in .NET MAUI application. By abstracting away the complexity of platform specific camera APIs, developers prevent themselves from having to worry about getting dizzy with answered and unannounced events, camera performance across all kinds of possible device configuration combinations, and learning how to integrate every device feature and API set.

We showcase our efforts to access both the front and the back cameras, implement zoom function, and control the flashlight, with real world examples. These tools enable you to extend your application to maximize the device hardware, offering customers advanced feature.

CommunityToolkit.Maui.Camera will be a key part of providing community driven packages that make it easy for .NET MAUI developers to build efficient cross platform applications. Continue to experiment with the toolkit’s features to build innovative applications taking advantage of what modern devices have to offer.

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