Compiling and Running code at runtime in .Net Core 1.0

Question

Is it possible to compile and run C# code at runtime in the new .Net Core (better .Net Standard Platform)? I have seen some examples (.Net Framework), but they used NuGet pa

Answer 1

Both previous answers didn't work for me in .NET Core 2.2 environment on Windows. More references are needed.

So with the help of https://stackoverflow.com/a/39260735/710069 solution, I have ended up with this code:

var dotnetCoreDirectory = System.Runtime.InteropServices.RuntimeEnvironment.GetRuntimeDirectory();

var compilation = CSharpCompilation.Create("LibraryName")
    .WithOptions(new CSharpCompilationOptions(OutputKind.DynamicallyLinkedLibrary))
    .AddReferences(
        MetadataReference.CreateFromFile(typeof(object).GetTypeInfo().Assembly.Location),
        MetadataReference.CreateFromFile(typeof(Console).GetTypeInfo().Assembly.Location),
        MetadataReference.CreateFromFile(Path.Combine(dotnetCoreDirectory, "mscorlib.dll")),
        MetadataReference.CreateFromFile(Path.Combine(dotnetCoreDirectory, "netstandard.dll")),
        MetadataReference.CreateFromFile(Path.Combine(dotnetCoreDirectory, "System.Runtime.dll")))
    .AddSyntaxTrees(CSharpSyntaxTree.ParseText(
        @"public static class ClassName 
        { 
            public static void MethodName() => System.Console.WriteLine(""Hello C# Compilation."");
        }"));

// Debug output. In case your environment is different it may show some messages.
foreach (var compilerMessage in compilation.GetDiagnostics())
    Console.WriteLine(compilerMessage);

Than output library to file:

var fileName = "LibraryName.dll";
var emitResult = compilation.Emit(fileName);
if (emitResult.Success)
{
    var assembly = AssemblyLoadContext.Default.LoadFromAssemblyPath(Path.GetFullPath(fileName));

    assembly.GetType("ClassName").GetMethod("MethodName").Invoke(null, null);
}

or to memory stream:

using (var memoryStream = new MemoryStream())
{
    var emitResult = compilation.Emit(memoryStream);
    if (emitResult.Success)
    {
        memoryStream.Seek(0, SeekOrigin.Begin);

        var context = AssemblyLoadContext.Default;
        var assembly = context.LoadFromStream(memoryStream);

        assembly.GetType("ClassName").GetMethod("MethodName").Invoke(null, null);
    }
}