Get started

To get started with ASP.NET Core in .NET 5 RC2, install the .NET 5 SDK. .NET RC2 also is included with Visual Studio 2019 16.8 Preview 4.

Visual Studio 2019 16.8 Preview 4 or later is required to use .NET 5 RC2 from Visual Studio. .NET 5 RC2 is also supported with the latest preview of Visual Studio for Mac. To use .NET 5 with Visual Studio Code, install the latest version of the C## extension.

Upgrade an existing project

To upgrade an existing ASP.NET Core app from .NET 5 RC1 to .NET 5 RC2:

• Update all Microsoft.AspNetCore.* package references to 5.0.0-rc.2.*.
• Update all Microsoft.Extensions.* package references to 5.0.0-rc.2.*.
• Update System.Net.Http.Json package references to 5.0.0-rc.2.*.
• Update Microsoft.AspNetCore.Components.Web.Extensions package references to 5.0.0-preview9.20513.1.
• Remove any package references to Microsoft.AspNetCore.Components.ProtectedBrowserStorage
• Update Microsoft.AspNetCore.Components.ProtectedBrowserStorage namespace to Microsoft.AspNetCore.Components.Server.ProtectedBrowserStorage.
• Remove unnecessary service registrations for ProtectedLocalStorage and ProtectedSessionStorage.
• Rename JSObjectReference to IJSObjectReference.
• In Blazor apps, replace CSS references to _framework/scoped.styles.css and __content/{project_name}/framework/scoped.styles.css with {project_name}.styles.css.

That’s it! You should be all ready to go.

See also the full list of breaking changes in ASP.NET Core for .NET 5.

What’s new?

Blazor CSS isolation improvements

In .NET 5 Preview 8 we introduced support for CSS isolation for Blazor components. Based on user feedback, we’ve made a number of improvements to CSS isolation in this release.

Previously, all component scoped CSS files including files from referenced projects or packages were compiled into a single bundle, scoped.styles.css. We now produce one bundle per referenced project or package and include those bundles into the app bundle through CSS @import statements.

The bundle names are now based on the project names: {project_name}.styles.css. Each bundle can be referenced from the root path of the app by default. This makes the path of the app bundle the same for both Blazor Server and Blazor WebAssembly projects:

<link href="BlazorApp1.styles.css" rel="stylesheet" />

Component specific styles can also now use normal wwwroot-relative paths to refer to related assets, like images. We’ve updated Razor Class Library template to make use of component specific styles following this pattern.

#aspnetcore #blazor