AspNetCore.Docs/aspnetcore/diagnostics/asp0009.md

title	description	author	monikerRange	ms.author	ms.date	uid
ASP0009: Do not use Configure with WebApplicationBuilder.WebHost	Learn about analysis rule ASP0009: Do not use Configure with WebApplicationBuilder.WebHost	safia	>= aspnetcore-7.0	safia	09/23/2022	diagnostics/asp0009

ASP0009: Do not use Configure with WebApplicationBuilder.WebHost

	Value
Rule ID	ASP0009
Category	Usage
Fix is breaking or non-breaking	Non-breaking

Cause

Configure can't be used with the WebHost property on WebApplicationBuilder.

Rule description

The WebApplicationBuilder doesn't support configuring the WebHost before build using the Configure extension method.

var builder = WebApplication.CreateBuilder(args);

builder.WebHost.Configure(webHostBuilder => {
    webHostBuilder.UseContentRootPath(Path.Combine(Directory.GetCurrentDirectory(), "myContentRoot"));
});

var app = builder.Build();

app.Run();

How to fix violations

To fix a violation of this rule, configure the WebHost directly on the WebApplicationBuilder. For example, instead of setting the content root path via Configure.

var builder = WebApplication.CreateBuilder(args);

builder.WebHost.Configure(webHostBuilder =>
{
    webHostBuilder.UseContentRoot(Path.Combine(Directory.GetCurrentDirectory(), "myContentRoot"));
});

var app = builder.Build();

app.Run();

Configure the content root path directly on the WebApplicationBuilder.

var builder = WebApplication.CreateBuilder(args);

builder.WebHost.UseContentRoot(Path.Combine(Directory.GetCurrentDirectory(), "myContentRoot"));

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.