Use a workaround with Roslyn to compile the code with C# 10 syntax, while still using Visual Studio 2019 as your IDE. This approach involves compiling the project using Roslyn from the command line or the Package Manager Console, rather than inside Visual Studio itself. Here's how you can set it up:
a. First, ensure you have the .NET SDK installed on your system, which contains Roslyn. You can download and install it here: https://dotnet.microsoft.com/download/dotnet
b. Open a command prompt (or Package Manager Console in Visual Studio), navigate to your project directory, and run:
dotnet new <your_project_name> --language CSharp -o <output_directory> --no-restore
cd <output_directory>
dotnet add <your_project_name>.csproj reference ../<path_to_dependencies>/<library_or_package_name>.csproj
dotnet add <your_project_name>.csproj <path_to_dependencies>/Microsoft.NET.Test.Sdk --version 16.4.0
dotnet add <your_project_name>.csproj "global::<namespace>" --project-type Package --language CSharp
dotnet restore
Replace `<your_project_name>` with the name of your project, `<output_directory>` with the desired output directory, `<path_to_dependencies>` with the path to any external libraries or dependencies you need, and `<library_or_package_name>`, `<namespace>` with appropriate values.
c. Set up your global using directives by adding a global.cs
file within a folder called 'Properties/CS' in your project, with the content similar to this:
using static System.Runtime.CompilerServices.Unsafe;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Threading;
using System.Threading.Tasks;
Replace the namespaces according to your project requirements.
d. Add a script file named <your_project_name>.csx
in your project, with the content as follows:
using static System.Runtime.CompilerServices.Unsafe;
using System;
using System.Linq;
public static void Main() {
GlobalUsage();
}
[System.Runtime.Versioning.RequiresMinorVersion(10, 0)]
static void GlobalUsage() {
global using System.Net;
var client = new WebClient();
var html = client.DownloadString("https://example.com");
Console.WriteLine(html);
}
Replace the <your_project_name>
in the file name accordingly. This script defines the GlobalUsage()
method, where you can write your C# 10 code, using the global usings.
e. Finally, compile your project with Roslyn:
dotnet run --project <your_project_name>.csproj
This command compiles and runs the project's main method, executing the `GlobalUsage()` method defined in your `<your_project_name>.csx` file.