asp0010.md

title	ASP0010: Do not use UseStartup with WebApplicationBuilder.WebHost
description	Learn about analysis rule ASP0010: Do not use UseStartup with WebApplicationBuilder.WebHost
author	safia
monikerRange	>= aspnetcore-7.0
ms.author	wpickett
ms.date	09/23/2022
uid	diagnostics/asp0010

ASP0010: Do not use UseStartup with WebApplicationBuilder.WebHost

	Value
Rule ID	ASP0010
Category	Usage
Fix is breaking or non-breaking	Non-breaking

Cause

UseStartup can't be used with WebApplicationBuilder.WebHost.

Rule description

The WebApplicationBuilder doesn't support configuration via a Startup class.

var builder = WebApplication.CreateBuilder(args);

builder.WebHost.UseStartup<Startup>();

var app = builder.Build();

app.Run();

How to fix violations

To fix a violation of this rule, leverage the Configuration and Services properties on the WebApplicationBuilder to modify configuration and DI directly, without the need for a startup class.

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddAuthentication();

var app = builder.Build();

app.Run();

When to suppress warnings

Do not suppress a warning from this rule. A misconfigured application can result in unexpected behavior at runtime.