DSoft.System.Mvvm.UI.MAUI 3.2.2301.91

System.Mvvm.UI.MAUI

Provides MAUI platform implementations for DSoft.System.Mvvm.UI

Functionality

• UI
  • Core UI functions for Showing Alerts and Confirmation Dialogs
  • UI Thread execution
  • Dependency injection support with IPlatformCoreUIProvider

Using System.Mvvm.UI.MAUI

The UI static class provides four methods as defined in the IPlatformCoreUIProvider interface.

• A central interface for calling some simple UI functions
  • ShowAlert(string title, string message)
    • Show an alert with a title and message using the platform implementation
  • ShowConfirmation(string title, string message)
    • Show a confirmation dialog and return the result using the platform implementation
  • InvokeOnUIThread(Action)
    • Execute the action on the UI thread using the platform implementation
  • InvokeOnUIThreadAsync(Action)
    • Execute the action on the UI thread asyncronously using the platform implementation

The standard UI functions can be called directly after adding the DSoft.Mvvm.UI package to your shared code

using System.Mvvm;
... 

var result = await UI.ShowConfirmationDialogAsync("Confirm this", "This is a platform specific confirmation message");

if (result)
    await UI.ShowAlertAsync("YAY!", "You confirmed that");

In the MAUI project that contains the App class(or other sub-class of Application), add the DSoft.System.Mvvm.UI.MAUI package.

Call the MvvmManager.Init method in the shared code, such as Application.OnStart

using System.Mvvm;
... 
public partial class App : Application
{
    protected override OnStart()
    {
        base.OnStart();

        MvvmManager.Init();
    }
}

Dependency Injection

Instead of using the static UI class you can use dependency injection to access the platform implementation of IPlatformCoreUIProvider using extensions for IServiceCollection provided by the platform specific packages.

After adding DSoft.System.Mvvm.UI.MAUI to the application project you can register the core UI implementations of IPlatformCoreUIProvider with the ServiceProvider during configuration of the services using the AddCoreUI extension method.

using System.Mvvm;
... 
public static class MauiProgram
{
	public static MauiApp CreateMauiApp()
	{
		var builder = MauiApp.CreateBuilder();
		builder
			.UseMauiApp<App>()
			.ConfigureFonts(fonts =>
			{
				fonts.AddFont("OpenSans-Regular.ttf", "OpenSansRegular");
				fonts.AddFont("OpenSans-Semibold.ttf", "OpenSansSemibold");
			});

        builder.Services.AddCore();

		return builder.Build();
	}
}

Once the core UI is registered you can use IPlatformCoreUIProvider with dependency injection in class constructors.

using System.Mvvm;
... 
public class SharedClassToDoThingsIn
{
   private readonly IPlatformCoreUIProvider _coreUIProvider;

    public SharedClassToDoThingsIn(IPlatformCoreUIProvider coreUIProvider)
    {
        _coreUIProvider = coreUIProvider;
    }

    public async Task SayHello()
    {
        await _coreUIProvider.ShowAlertAsync("Congrats", "You called the ICoreUIProvider instance");
    }
}

ISevicesCollection extensions

On other platforms, when configuring the services there is normally a ConfigureServices extension to make it easier to parse a delegate to configure the services. With MauiAppBuilder this is not available so we created MauiExtensions to add this functionality back in.

	public static MauiApp CreateMauiApp()
	{
		var builder = MauiApp.CreateBuilder();
		builder
			.UseMauiApp<App>()
			.ConfigureFonts(fonts =>
			{
				fonts.AddFont("OpenSans-Regular.ttf", "OpenSansRegular");
				fonts.AddFont("OpenSans-Semibold.ttf", "OpenSansSemibold");
			})
			.ConfigureServices(services =>
            {
                services.AddCoreUI();
            });

		return builder.Build();
	}

MauiHostProxy

MauiApp does not implement IHost and so it cannot be used directly with DSoft.System.Mvvm.Hosting. This makes it harder to access the IServiceProvider instance to retrieve the services. We've created MauiHostProxy to allow you to use MauiApp with DSoft.System.Mvvm.Hosting by providing a simple wrapper around it which does implement IHost.

You simply instatiate a new instance of MauiHostProxy with the output of MauiAppBuilder.Build and assigned it to ServiceHost.Host as usual.

    public static MauiApp CreateMauiApp()
    {
      var builder = MauiApp.CreateBuilder();
      builder
        .UseMauiApp<App>()
        .ConfigureFonts(fonts =>
        {
          fonts.AddFont("OpenSans-Regular.ttf", "OpenSansRegular");
          fonts.AddFont("OpenSans-Semibold.ttf", "OpenSansSemibold");
        })
        .ConfigureServices(ConfigureServices);

      var app = builder.Build();

      //configure the servicehost host
      ServiceHost.Host = new MauiHostProxy(app);

      return app;
    }

You can then retrieve the implementation directly from ServiceHost as before, theres not need to keep a refernce to MauiApp in your shared code.

using System.Mvvm;
... 

var _coreUIProvider = ServiceHost.GetRequiredService<IPlatformCoreUIProvider>();

await _coreUIProvider.ShowAlertAsync("Congrats", "You called the ICoreUIProvider instance");

IMAUIPlatformUIProvider

IMAUIPlatformUIProvider is a platform specific interface that the platform implementation of IPlatformCoreUIProvider implements. It provides access to some additonal MAUI properties such as the current Application.

Use can retrieve the implementation directly from the services provider or ServiceHost if you are using DSoft.System.Mvvm.Hosting

using System.Mvvm;
... 

var _formsUIProvider = ServiceHost.GetRequiredService<IMAUIPlatformUIProvider>();

var currentApp = _formsUIProvider.CurrentApplication;