RhSolutions-AddIn/RhSolutions.AddIn/AddIn/RhSolutionsAddIn.cs

using ExcelDna.IntelliSense;
using System.Net;

namespace RhSolutions.AddIn;

public sealed class RhSolutionsAddIn : IExcelAddIn
{
    public static Application Excel { get; private set; }
    public static ServiceProvider ServiceProvider { get; set; }
    public static IAddInConfiguration Configuration { get; set; }

    public void AutoOpen()
    {
        IServiceCollection Services = new ServiceCollection();

        Services.AddHttpClient()
            .AddSingleton<IDatabaseClient, RhDatabaseClient>()
            .AddSingleton<IAddInConfiguration, AddInConfiguration>()
            .AddSingleton((Application)ExcelDnaUtil.Application);

        ServiceProvider = Services.BuildServiceProvider();
        Configuration = ServiceProvider.GetService<IAddInConfiguration>();
        Excel = ServiceProvider.GetService<Application>();

        IntelliSenseServer.Install();
        EventsUtil.Initialize();

        ServicePointManager.SecurityProtocol =
            SecurityProtocolType.Tls12;
    }

    public void AutoClose()
    {
        IntelliSenseServer.Uninstall();
        EventsUtil.Uninitialize();
    }
}