Migrate from ASP.NET Core 3.1 to 6.0
This article explains how to update an existing ASP.NET Core 3.1 project to ASP.NET Core 6.0. To upgrade from ASP.NET Core 5.0 to 6.0, see Migrate from ASP.NET Core 5.0 to 6.0.
Prerequisites
- Visual Studio 2022 with the ASP.NET and web development workload.
- .NET 6.0 SDK
Update .NET SDK version in global.json
If you rely upon a global.json
file to target a specific .NET SDK version, update the version
property to the .NET 6.0 SDK version that's installed. For example:
{
"sdk": {
- "version": "3.1.200"
+ "version": "6.0.100"
}
}
Update the target framework
Update the project file's Target Framework Moniker (TFM) to net6.0
:
<Project Sdk="Microsoft.NET.Sdk.Web">
<PropertyGroup>
- <TargetFramework>netcoreapp3.1</TargetFramework>
+ <TargetFramework>net6.0</TargetFramework>
</PropertyGroup>
</Project>
Update package references
In the project file, update each Microsoft.AspNetCore.*
, Microsoft.EntityFrameworkCore.*
, Microsoft.Extensions.*
, and System.Net.Http.Json
package reference's Version
attribute to 6.0.0 or later. For example:
<ItemGroup>
- <PackageReference Include="Microsoft.AspNetCore.JsonPatch" Version="3.1.6" />
- <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="3.1.6" />
- <PackageReference Include="Microsoft.Extensions.Caching.Abstractions" Version="3.1.6" />
- <PackageReference Include="System.Net.Http.Json" Version="3.2.1" />
+ <PackageReference Include="Microsoft.AspNetCore.JsonPatch" Version="6.0.0" />
+ <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="6.0.0" />
+ <PackageReference Include="Microsoft.Extensions.Caching.Abstractions" Version="6.0.0" />
+ <PackageReference Include="System.Net.Http.Json" Version="6.0.0" />
</ItemGroup>
Delete bin
and obj
folders
You may need to delete the bin
and obj
folders. Run dotnet nuget locals --clear all
to clear the NuGet package cache.
Minimal hosting model
The ASP.NET Core templates generate code using the new minimal hosting model. The minimal hosting model unifies Startup.cs
and Program.cs
into a single Program.cs
file. ConfigureServices
and Configure
are no longer used. Apps migrating from ASP.NET Core 3.1 to 6.0 don't need to use the minimal hosting model, using Startup
and the Generic Host used by the ASP.NET Core 3.1 templates is fully supported.
To use Startup
with the new minimal hosting model, see Use Startup with the new minimal hosting model.
To migrate to the new minimal hosting model using the following pattern used by the ASP.NET Core 6.0 templates, see Code samples migrated to the new minimal hosting model in ASP.NET Core 6.0 and Migrate from ASP.NET Core 5.0 to 6.0
Update Razor class libraries (RCLs)
Migrate Razor class libraries (RCLs) to take advantage of new APIs or features that are introduced as part of ASP.NET Core 6.0.
To update a RCL that targets components:
Update the following properties in the project file:
<Project Sdk="Microsoft.NET.Sdk.Razor"> <PropertyGroup> - <TargetFramework>netstandard2.0</TargetFramework> - <RazorLangVersion>3.0</RazorLangVersion> + <TargetFramework>net6.0</TargetFramework> </PropertyGroup>
Update other packages to their latest versions. The latest versions can be found at NuGet.org.
To update an RCL targeting MVC, update the following properties in the project file:
<Project Sdk="Microsoft.NET.Sdk.Razor">
<PropertyGroup>
- <TargetFramework>netcoreapp3.1</TargetFramework>
+ <TargetFramework>net6.0</TargetFramework>
<AddRazorSupportForMvc>true</AddRazorSupportForMvc>
</PropertyGroup>
Blazor
To adopt all of the 5.0 features and 6.0 features for Blazor apps, we recommend the following process:
- Create a new 6.0 Blazor project from one of the Blazor project templates. For more information, see Tooling for ASP.NET Core Blazor.
- Move the app's components and code to the 6.0 app making modifications to adopt the new 5.0 and 6.0 features.
Update Docker images
For apps using Docker, update your Dockerfile FROM
statements and scripts. Use a base image that includes the ASP.NET Core 6.0 runtime. Consider the following docker pull
command difference between ASP.NET Core 3.1 and 6.0:
- docker pull mcr.microsoft.com/dotnet/core/aspnet:3.1
+ docker pull mcr.microsoft.com/dotnet/aspnet:6.0
As part of the move to ".NET" as the product name, the Docker images moved from the mcr.microsoft.com/dotnet/core
repositories to mcr.microsoft.com/dotnet
. For more information, see .NET 5.0 - Docker Repo Name Change (dotnet/dotnet-docker #1939).
Model binding changes in ASP.NET Core MVC and Razor Pages
DateTime
values are model bound as UTC times
In ASP.NET Core 3.1 and earlier, DateTime
values were model-bound as local time, where the timezone was determined by the server. DateTime
values bound from input formatting (JSON) and DateTimeOffset
values were bound as UTC timezones.
In ASP.NET Core 5.0 and later, model binding consistently binds DateTime
values with the UTC timezone.
To retain the previous behavior, remove the DateTimeModelBinderProvider
in Startup.ConfigureServices
:
services.AddControllersWithViews(options =>
options.ModelBinderProviders.RemoveType<DateTimeModelBinderProvider>());
ComplexObjectModelBinderProvider
\ ComplexObjectModelBinder
replace ComplexTypeModelBinderProvider
\ ComplexTypeModelBinder
To add support for model binding C# 9 record types, the ComplexTypeModelBinderProvider is:
- Annotated as obsolete.
- No longer registered by default.
Apps that rely on the presence of the ComplexTypeModelBinderProvider
in the ModelBinderProviders
collection need to reference the new binder provider:
- var complexModelBinderProvider = options.ModelBinderProviders.OfType<ComplexTypeModelBinderProvider>();
+ var complexModelBinderProvider = options.ModelBinderProviders.OfType<ComplexObjectModelBinderProvider>();
UseDatabaseErrorPage
obsolete
The ASP.NET Core 3.1 templates that include an option for individual user accounts generate a call to UseDatabaseErrorPage. UseDatabaseErrorPage
is now obsolete and should be replaced with a combination of AddDatabaseDeveloperPageExceptionFilter
and UseMigrationsEndPoint
, as shown in the following code:
public void ConfigureServices(IServiceCollection services)
{
services.AddDbContext<ApplicationDbContext>(options =>
options.UseSqlServer(
Configuration.GetConnectionString("DefaultConnection")));
+ services.AddDatabaseDeveloperPageExceptionFilter();
services.AddDefaultIdentity<IdentityUser>(options => options.SignIn.RequireConfirmedAccount = true)
.AddEntityFrameworkStores<ApplicationDbContext>();
services.AddRazorPages();
}
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
+ app.UseMigrationsEndPoint();
- app.UseDatabaseErrorPage();
}
else
{
app.UseExceptionHandler("/Error");
app.UseHsts();
}
For more information, see Obsoleting DatabaseErrorPage middleware (dotnet/aspnetcore #24987).
ASP.NET Core Module (ANCM)
If the ASP.NET Core Module (ANCM) wasn't a selected component when Visual Studio was installed or if a prior version of the ANCM was installed on the system, download the latest .NET Core Hosting Bundle Installer (direct download) and run the installer. For more information, see Hosting Bundle.
Application name change
In .NET 6, WebApplicationBuilder normalizes the content root path to end with a DirectorySeparatorChar. Most apps migrating from HostBuilder or WebHostBuilder won't have the same app name because they aren't normalized. For more information, see SetApplicationName
Review breaking changes
See the following resources:
- Identity: Default Bootstrap version of UI changed
- Breaking changes for migration from version 3.1 to 5.0. ASP.NET Core and Entity Framework Core are also included in the list.
- Breaking changes for migration from version 5.0 to 6.0: Includes ASP.NET Core and Entity Framework Core.
- Announcements GitHub repository (aspnet/Announcements,
6.0.0
label): Includes breaking and non-breaking information. - Announcements GitHub repository (aspnet/Announcements,
5.0.0
label): Includes breaking and non-breaking information.