How do I get hold of NuGet.VisualStudio.Contracts.INuGetProjectService ?

[ekrogh]

Visual Studio (2022) claims that:

[deprecated] interface NuGetVisualStudio.IVsPackagelnstallerServices
Contains methods to query for installed packages within the current solution.
CS061& 'IVsPackagelnstallerServices' is obsolete: 'Use INuGetProjectService in the NuGet.VisualStudio.Contracts package instead.'
Show potential fixes (AltEnter or Ctrl.)

But if I try

var tst =	await VS.GetMefServiceAsync<NuGet.VisualStudio.Contracts.INuGetProjectService>();

it thwows this:

Microsoft.VisualStudio.Composition.CompositionFailedException
HResult=0x80131500
Message=Expected 1 export(s) with contract name "NuGet.VisualStudio.Contracts.INuGetProjectService" but found 0 after applying applicable constraints.
Source=Microsoft.VisualStudio.Composition
StackTrace:
at Microsoft.VisualStudio.Composition.ExportProvider.GetExports(ImportDefinition importDefinition)
at Microsoft.VisualStudio.Composition.ExportProvider.GetExports[T,TMetadataView](String contractName, ImportCardinality cardinality)
at Microsoft.VisualStudio.Composition.ExportProvider.GetExport[T,TMetadataView](String contractName)
at Microsoft.VisualStudio.Composition.ExportProvider.GetExportedValueT
at Microsoft.VisualStudio.ComponentModelHost.ComponentModel.GetServiceT
at Community.VisualStudio.Toolkit.VS.d__421.MoveNext() at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at System.Runtime.CompilerServices.TaskAwaiter1.GetResult()
at xxx.CheckSolutionType.d__0.MoveNext() in D:\Users\eigil\projects\VSIX\xxx\xxx\Helpers\CheckSolutionType.cs:line 24

This exception was originally thrown at this call stack:
[External Code]
xxx.CheckSolutionType.ThisIsXamarinAsync() in CheckSolutionType.cs

How do I get hold of NuGet.VisualStudio.Contracts.INuGetProjectService ?

[reduckted]

Here's how it's used in the Roslyn project:
https://github.com/dotnet/roslyn/blob/e079a36f3ade7cda2a464e4fdcde0a11577fd1ea/src/VisualStudio/Core/Def/Packaging/PackageInstallerServiceFactory.cs#L533-L540

Here's an example:

IBrokeredServiceContainer serviceContainer;
IServiceBroker serviceBroker;
INuGetProjectService nugetService;

serviceContainer = await VS.GetServiceAsync<SVsBrokeredServiceContainer, IBrokeredServiceContainer>();
serviceBroker = serviceContainer?.GetFullAccessServiceBroker();
nugetService = await serviceBroker.GetProxyAsync<INuGetProjectService>(NuGetServices.NuGetProjectServiceV1, cancellationToken: default);

using (nugetService as IDisposable)
{
    InstalledPackagesResult result;

    result = await nugetService.GetInstalledPackagesAsync(projectId, CancellationToken.None);

    foreach (NuGetInstalledPackage package in result.Packages)
    {
        Debug.WriteLine(package.Id);
    }
}

[workgroupengineering]

Do you know if there is a way to get notified when one or more nuget packages are installed / removed without polling?