public WebHost(
IServiceCollection appServices,
IServiceProvider hostingServiceProvider,
WebHostOptions options,
IConfiguration config,
AggregateException hostingStartupErrors)
{
if (appServices == null)
{
throw new ArgumentNullException(nameof(appServices));
}
if (hostingServiceProvider == null)
{
throw new ArgumentNullException(nameof(hostingServiceProvider));
}
if (config == null)
{
throw new ArgumentNullException(nameof(config));
}
_config = config;
_hostingStartupErrors = hostingStartupErrors;
_options = options;
_applicationServiceCollection = appServices;
_hostingServiceProvider = hostingServiceProvider;
_applicationServiceCollection.AddSingleton <IApplicationLifetime, ApplicationLifetime>();
_applicationServiceCollection.AddSingleton <HostedServiceExecutor>();
}
private IServiceCollection BuildCommonServices(out AggregateException hostingStartupErrors)
{
hostingStartupErrors = null;
_options = new WebHostOptions(_config, Assembly.GetEntryAssembly()?.GetName().Name);
if (!_options.PreventHostingStartup)
{
var exceptions = new List <Exception>();
// Execute the hosting startup assemblies
foreach (var assemblyName in _options.HostingStartupAssemblies)
{
try
{
var assembly = Assembly.Load(new AssemblyName(assemblyName));
foreach (var attribute in assembly.GetCustomAttributes <HostingStartupAttribute>())
{
var hostingStartup = (IHostingStartup)Activator.CreateInstance(attribute.HostingStartupType);
hostingStartup.Configure(this);
}
}
catch (Exception ex)
{
// Capture any errors that happen during startup
exceptions.Add(new InvalidOperationException($"Startup assembly {assemblyName} failed to execute. See the inner exception for more details.", ex));
}
}
if (exceptions.Count > 0)
{
hostingStartupErrors = new AggregateException(exceptions);
}
}
var contentRootPath = ResolveContentRootPath(_options.ContentRootPath, AppContext.BaseDirectory);
// Initialize the hosting environment
var _hostingEnvironment = new HostingEnvironment
{
ContentRootPath = contentRootPath,
};
_context.HostingEnvironment = _hostingEnvironment;
var services = new ServiceCollection();
services.AddSingleton <IHostingEnvironment>(_hostingEnvironment);
services.AddSingleton(_context);
var builder = new ConfigurationBuilder()
.AddInMemoryCollection(_config.AsEnumerable());
foreach (var configureAppConfiguration in _configureAppConfigurationBuilderDelegates)
{
configureAppConfiguration(_context, builder);
}
var configuration = builder.Build();
services.AddSingleton <IConfiguration>(configuration);
_context.Configuration = configuration;
var listener = new DiagnosticListener("Microsoft.AspNetCore");
services.AddSingleton <DiagnosticListener>(listener);
services.AddSingleton <DiagnosticSource>(listener);
services.AddTransient <IApplicationBuilderFactory, ApplicationBuilderFactory>();
services.AddTransient <IHttpContextFactory, HttpContextFactory>();
services.AddScoped <IMiddlewareFactory, MiddlewareFactory>();
services.AddOptions();
services.AddLogging();
// Conjure up a RequestServices
services.AddTransient <IStartupFilter, AutoRequestServicesStartupFilter>();
services.AddTransient <IServiceProviderFactory <IServiceCollection>, DefaultServiceProviderFactory>();
// Ensure object pooling is available everywhere.
services.AddSingleton <ObjectPoolProvider, DefaultObjectPoolProvider>();
if (!string.IsNullOrEmpty(_options.StartupAssembly))
{
try
{
var startupType = StartupLoader.FindStartupType(_options.StartupAssembly, _hostingEnvironment.EnvironmentName);
if (typeof(IStartup).GetTypeInfo().IsAssignableFrom(startupType.GetTypeInfo()))
{
services.AddSingleton(typeof(IStartup), startupType);
}
else
{
services.AddSingleton(typeof(IStartup), sp =>
{
var hostingEnvironment = sp.GetRequiredService <IHostingEnvironment>();
var methods = StartupLoader.LoadMethods(sp, startupType, hostingEnvironment.EnvironmentName);
return(new ConventionBasedStartup(methods));
});
}
}
catch (Exception ex)
{
var capture = ExceptionDispatchInfo.Capture(ex);
services.AddSingleton <IStartup>(_ =>
{
capture.Throw();
return(null);
});
}
}
foreach (var configureServices in _configureServicesDelegates)
{
configureServices(_context, services);
}
return(services);
}