What's new in .Net Core 3.0

The .Net Core preview 1 version was released in Dec’ 2018. One of the major enhancements in this version of .Net Core is the support for Windows & WPF applications. Additionally .Net Core also brings enhancements to the way the applications are packaged and shared. Enhancements for faster JSON processing using Utf8JsonReader. Finally .NET Core 3.0 implements .NET Standard 2.1.

Let us see each of the new features of .Net Core 3.0 in detail

Executables
.Net Core 3.0 creates a default executable file like .exe based on the environment of the SDK used to build the application. When we run the dotnet build (or) dotnet publish commands the executable file gets created. The previous versions of .Net Core used to create a Framework-dependent deployment (or) Self-contained deployment.

These executable files are similar to the executable files which used to get created in the traditional .Net environment, we can run the application by double clicking on the .exe or execute from the console. Also the dotnet build command copies the dependent NuGet package files to the build folder.

Local dotnet tools
We know that .Net Core 2.1 introduced global tools, which makes the tools available for use anywhere in the machine. .Net Core 3.0 introduces local tools, which makes the tools available in a specific folder / repository these tools are not available globally.

Local tools rely on a manifest file name dotnet-tools.json in your current directory. This manifest file defines the tools to be available. By creating this manifest file at the root of your repository, you ensure anyone cloning your code can restore and use the tools. This is similar to the package.json file in Node.js, which defines all the dependencies for the application.

To add local tools to a directory, you need to first create the tool manifest file. To add local tools to a directory, you need to first create the tool manifest file dotnet-tools.json

To restore the dependencies for an application use the restore command as follows. This command will get all the dependencies specified in the manifest file.

dotnet tool restore

Windows Desktop Applications
.Net Core 3.0 supports creation of Windows Desktop applications and WPF applications using the Windows Desktop component. The Windows Desktop component is part of the Windows .NET Core 3.0 SDK. You can create a new WPF or Windows Forms app with the following dotnet commands:

dotnet new wpf

dotnet new winforms

.NET Core console project uses the Microsoft.NET.Sdk SDK, while a Windows Desktop app uses the Microsoft.NET.Sdk.WindowsDesktop SDK.