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Make the IServiceProvider of your MAUI application accessible with the MVVM CommunityToolkit

Make the IServiceProvider of your MAUI application accessible with the MVVM CommunityToolkit

As you might know, I am in the process of converting all my internal used libraries to be .NET MAUI compatible. This is quite a bigger task than initially thought, although I somehow enjoy the process. One thing I ran pretty fast into is the fact that you can’t access the MAUI app’s IServiceProvider by default.

Possible solutions

As always, there is more than one solution. While @DavidOrtinau shows one approach in the WeatherTwentyOne application that accesses the platform implementation of the Services, I prefer another approach that uses, in fact, Dependency Injection to achieve the same goal.

Implementation

I am subclassing the Microsoft.Maui.Controls.Application to provide my own, overloaded constructor where I inject the IServiceProvider used by the MAUI application. Within the constructor, I am using the MVVM CommunityToolkit’s Ioc.Default.ConfigureServices method to initialize the toolkit’s Ioc handler. Here is the code:

using CommunityToolkit.Mvvm.DependencyInjection;

namespace MauiTestApp
{
	public class MyMauiAppImpl : Microsoft.Maui.Controls.Application
	{
		public MyMauiAppImpl(IServiceProvider services) 
		{
            Ioc.Default.ConfigureServices(services);
        }
	}
}

Usage

Using the class is straight forward. Open your App.xaml file and replace the Application base with your MyMauiAppImpl:

<local:MyMauiAppImpl
             xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:local="clr-namespace:MauiTestApp"
             x:Class="MauiTestApp.App">
    <Application.Resources>
        <ResourceDictionary>
            <ResourceDictionary.MergedDictionaries>
                <ResourceDictionary Source="Resources/Styles/Colors.xaml" />
                <ResourceDictionary Source="Resources/Styles/Styles.xaml" />
            </ResourceDictionary.MergedDictionaries>
        </ResourceDictionary>
    </Application.Resources>
</local:MyMauiAppImpl>

And, of course, the same goes for the code behind-file App.xaml.cs:

namespace MauiTestApp;

public partial class App : MyMauiAppImpl
{
	public App(IServiceProvider serviceProvider) : base(serviceProvider)
	{
		InitializeComponent();

		MainPage = new AppShell;
	}

}

That’s it, you can now use the MVVM CommunityToolkit’s Ioc.Default implementation to access the registered Services, ViewModels and Views.

Conclusion

In this post, I showed you a simple (and even easily reusable way) of making the IServiceProvider of your .NET MAUI application available. I also linked to an alternative approach, if you do not want to subclass the application object, I recommend that way.

As always, I hope this post is helpful for some of you.

Until the next post, happy coding, everyone!
Posted by msicc in Dev Stories, MAUI, Xamarin, 1 comment