abp/templates/wpf/src/MyCompanyName.MyProjectName/MyProjectNameModule.cs

using Microsoft.Extensions.DependencyInjection;
using Volo.Abp.Autofac;
using Volo.Abp.Modularity;

namespace MyCompanyName.MyProjectName
{
    [DependsOn(typeof(AbpAutofacModule))]
    public class MyProjectNameModule : AbpModule
    {
        public override void ConfigureServices(ServiceConfigurationContext context)
        {
            context.Services.AddSingleton<MainWindow>();
        }
    }
}