How to use MAUI IAppInfo with Microsoft.Extensions.DependencyInjection

I’ve been using my own little AppInfo class with Microsoft.Extensions.DependencyInjection, but ran into a cross-platform issue with it, so now I want to switch to using the built-in MAUI AppInfo, but I’m having issues with getting it registered in the DI.

So, the code I have working with my own class was (just the relevant bits)…

using Microsoft.Extensions.DependencyInjection;
using MyAppInfoNamespace;
// other stuff
MauiAppBuilder builder=MauiApp.CreateBuilder();
builder.Services
    .AddSingleton<IMyAppInfo,MyAppInfoImplementation>()
//other services
    ;
// rest of builder code

I removed the using for my library, as well as the link to the DLL, and added…

using Microsoft.Maui.ApplicationModel;

The issue I’m having is with getting the rest of the syntax working.

If I put…

    .AddSingleton<IAppInfo,AppInfo>()

which is the same syntax I used with my own class, just altered appropriately, VS tells me "static types cannot be used as type arguments"

but if I put just…

    .AddSingleton<IAppInfo>()

then I get…

Cannot instantiate implementation type ‘Microsoft.Maui.ApplicationModel.IAppInfo’ for service type ‘Microsoft.Maui.ApplicationModel.IAppInfo’.

When I Google these error messages I can only find stuff not about MAUI. So what do I need to do to get the AddSingleton line of code working with MAUI AppInfo? I’ve run out of things to try.

thanks,
Donald.

>Solution :

As u mentioned AppInfo is a static class. But AppInfo has the property Current.

public static IAppInfo Current { get; }

This is what you need to add to the container.

builder.Services.AddSingleton(AppInfo.Current);

If you wonder, this is the same as

builder.Services.AddSingleton<IAppInfo>(AppInfo.Current);

Example for Constructor Injection

public AboutViewModel(IAppInfo appinfo)
{
    VersionString = appinfo.VersionString;
    PackageName = appinfo.PackageName;
    Name = appinfo.Name;
    Build = appinfo.BuildString;
}

Edit:
you don’t need the using statement:

using Microsoft.Extensions.DependencyInjection;