.NET MAUI Embedding - MauiCommunityToolkit

The controls from MauiCommunityToolkit can be used in an Uno Platform application via .NET MAUI Embedding.

Sample App

An existing sample app that showcases the controls is available here.

Getting Started

Create a new application using the unoapp template, enabling .NET MAUI Embedding. In this case, we're going to use the Blank template (-preset blank) and include .NET MAUI Embedding support (-maui).
```
dotnet new unoapp -preset blank -maui -o MauiEmbeddingApp
```
Add a reference to the CommunityToolkit.Maui NuGet package to the MauiEmbeddingApp.MauiControls project.

In the AppBuilderExtensions class, on MauiEmbeddingApp.MauiControls project, update the UseMauiControls extension method to call the UseMauiCommunityToolkit method.

using CommunityToolkit.Maui;

namespace MauiEmbeddingApp;

public static class AppBuilderExtensions
{
    public static MauiAppBuilder UseMauiControls(this MauiAppBuilder builder)
        => builder
            .UseMauiCommunityToolkit()
            .ConfigureFonts(fonts =>
            {
                fonts.AddFont("MauiEmbeddingApp/Assets/Fonts/OpenSansRegular.ttf", "OpenSansRegular");
                fonts.AddFont("MauiEmbeddingApp/Assets/Fonts/OpenSansSemibold.ttf", "OpenSansSemibold");
            });
}

Adding DrawingView

Update the EmbeddedControl.xaml in the MauiEmbedding.MauiControls project with the following XAML that includes the DrawingView control

<?xml version="1.0" encoding="utf-8" ?>
<ContentView xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
            xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
            xmlns:toolkit="http://schemas.microsoft.com/dotnet/2022/maui/toolkit"
            x:Class="MauiEmbeddingApp.MauiControls.EmbeddedControl"
            HorizontalOptions="Fill"
            VerticalOptions="Fill">
    <toolkit:DrawingView IsMultiLineModeEnabled="{Binding IsMultiLineModeEnabled}"
                        LineColor="Fuchsia"
                        LineWidth="5"
                        ShouldClearOnFinish="{Binding ShouldCleanOnFinish}" />
</ContentView>

Note

You may notice that the Binding markup extension is used on some properties. The MauiEmbedding can handle bindings between Maui Controls and UnoPlatform, just make sure the property in the Binding expression matches the property on your ViewModel.

Update the EmbeddedControl.xaml.cs with the following code.

namespace MauiEmbeddingApp.MauiControls;

public partial class EmbeddedControl : ContentView
{
    public EmbeddedControl()
    {
        this.InitializeComponent();
    }
}

Now let's create the controls that will control the DrawingView.IsMultiLineModeEnabled and DrawingView.ShouldClearOnFinish properties. Update the MainPage.xaml in the MauiEmbeddingApp project with the following xaml:

<Page x:Class="MauiEmbeddingApp.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto" />
            <RowDefinition Height="*" />
        </Grid.RowDefinitions>
        <StackPanel>
            <TextBlock Text="Clean on Finish:" />
            <ToggleSwitch IsOn="{Binding ShouldCleanOnFinish, Mode=TwoWay}" />

            <TextBlock Text="MultiLineMode:" />
            <ToggleSwitch x:Name="MultiLineMode"
                        IsOn="{Binding IsMultiLineModeEnabled, Mode=TwoWay}" />
        </StackPanel>

        <embed:MauiHost xmlns:controls="using:MauiEmbeddingApp.MauiControls"
                        xmlns:embed="using:Uno.Extensions.Maui"
                        Grid.Row="1"
                        Source="controls:EmbeddedControl" />
    </Grid>
</Page>

It's time to create the ViewModel that will hold the properties that will be data bound to the DrawingView control. On MauiEmbeddingApp project, create a new folder called ViewModels and add a new class called MainViewModel. This class will have the following code:
```
namespace MauiEmbeddingApp.ViewModels;

partial class MainViewModel : ObservableObject
{
    [ObservableProperty]
    bool isMultiLineModeEnabled;

    [ObservableProperty]
    bool shouldCleanOnFinish;
}
```
The MainViewModel uses the ObservableObject base class that comes from the CommunityToolkit.MVVM NuGet package. This significantly reduces the amount of boilerplate code required. Add a reference to the CommunityToolkit.Mvvm NuGet package to the MauiEmbeddingApp project.

The final step is to add the MainViewModel as the DataContext of the Page in the MainPage.xaml file. Here's how the final xaml should look.

<Page x:Class="MauiEmbeddingApp.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:MauiEmbeddingApp.ViewModels"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
    <Page.DataContext>
        <local:MainViewModel />
    </Page.DataContext>
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto" />
            <RowDefinition Height="*" />
        </Grid.RowDefinitions>
        <StackPanel>
            <TextBlock Text="Clean on Finish:" />
            <ToggleSwitch IsOn="{Binding ShouldCleanOnFinish, Mode=TwoWay}" />

            <TextBlock Text="MultiLineMode:" />
            <ToggleSwitch x:Name="MultiLineMode"
                        IsOn="{Binding IsMultiLineModeEnabled, Mode=TwoWay}" />
        </StackPanel>

        <embed:MauiHost xmlns:controls="using:MauiEmbeddingApp.MauiControls"
                        xmlns:embed="using:Uno.Extensions.Maui"
                        Grid.Row="1"
                        Source="controls:EmbeddedControl" />
    </Grid>
</Page>

Now the project is good to go! Press F5 and you should see the DrawingView control working as expected. And tweaking the ToggleSwitch controls should change the DrawingView behavior.

App Render Output

Android:
Windows: