I would like to reuse the script as a dynamic assembly in another Roslyn compilation that does not use scripts, but I can’t figure out how to do this for my whole life.
For example, let's say I create a script in the usual way, and then release the script as an assembly into a byte stream, using something like:
var compilationOptions = new CSharpCompilationOptions(OutputKind.DynamicallyLinkedLibrary);
var compilation = script.GetCompilation().WithOptions(compilationOptions);
using (var ms = new MemoryStream())
{
EmitResult result = compilation.Emit(ms);
ms.Seek(0, SeekOrigin.Begin);
assembly = Assembly.Load(ms.ToArray());
}
Now let's say that I want to transfer this assembly to another compilation without scripts as a reference. I can’t just use assembly, since none of the methods MetadataReference.CreateFrom...()support transferring the actual instance assembly. As a dynamic assembly, it has no location, so I cannot use it MetadataReference.CreateFromFile().
MetadataReference.CreateFromStream() , , , , script ( , ). , , , :
System.InvalidCastException: [A]Foo cannot be cast to [B]Foo. Type A originates from 'R*19cecf20-a48e-4a31-9b65-4c0163eba857#1-0, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null' in the context 'LoadNeither' in a byte array. Type B originates from 'R*19cecf20-a48e-4a31-9b65-4c0163eba857#1-0, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null' in the context 'LoadNeither' in a byte array.
, , vs. . , , script, script.
7/29
, . https://github.com/daveaglick/ScriptingAssemblyReuse.
, , script Type , Type , , script. , -, . , , , , .
:
namespace ScriptingAssemblyReuse
{
public class Globals
{
public IFactory Factory { get; set; }
}
public interface IFactory
{
object Get();
}
public class Factory<T> : IFactory where T : new()
{
public object Get() => new T();
}
public class Program
{
public static void Main(string[] args)
{
new Program().Run();
}
private Assembly _scriptAssembly;
public void Run()
{
AppDomain.CurrentDomain.AssemblyResolve += OnAssemblyResolve;
// Create the script
Script<object> script = CSharpScript.Create(@"
public class Foo { }
Factory = new ScriptingAssemblyReuse.Factory<Foo>();
", ScriptOptions.Default.WithReferences(MetadataReference.CreateFromFile(typeof(IFactory).Assembly.Location)), typeof(Globals));
// Create a compilation and get the dynamic assembly
CSharpCompilationOptions scriptCompilationOptions = new CSharpCompilationOptions(OutputKind.DynamicallyLinkedLibrary);
Compilation scriptCompilation = script.GetCompilation().WithOptions(scriptCompilationOptions);
byte[] scriptAssemblyBytes;
using (MemoryStream ms = new MemoryStream())
{
EmitResult result = scriptCompilation.Emit(ms);
ms.Seek(0, SeekOrigin.Begin);
scriptAssemblyBytes = ms.ToArray();
}
_scriptAssembly = Assembly.Load(scriptAssemblyBytes);
// Evaluate the script
Globals globals = new Globals();
script.RunAsync(globals).Wait();
// Create the consuming compilation
string assemblyName = Path.GetRandomFileName();
CSharpParseOptions parseOptions = new CSharpParseOptions();
SyntaxTree syntaxTree = CSharpSyntaxTree.ParseText(@"
public class Bar
{
public void Baz(object obj)
{
Script.Foo foo = (Script.Foo)obj; // This is the line that triggers the exception
}
}", parseOptions, assemblyName);
CSharpCompilationOptions compilationOptions = new CSharpCompilationOptions(OutputKind.DynamicallyLinkedLibrary);
string assemblyPath = Path.GetDirectoryName(typeof(object).Assembly.Location);
CSharpCompilation compilation = CSharpCompilation.Create(assemblyName, new[] {syntaxTree},
new[]
{
MetadataReference.CreateFromFile(Path.Combine(assemblyPath, "mscorlib.dll")),
MetadataReference.CreateFromFile(Path.Combine(assemblyPath, "System.dll")),
MetadataReference.CreateFromFile(Path.Combine(assemblyPath, "System.Core.dll")),
MetadataReference.CreateFromFile(Path.Combine(assemblyPath, "System.Runtime.dll"))
}, compilationOptions);
using (MemoryStream ms = new MemoryStream(scriptAssemblyBytes))
{
compilation = compilation.AddReferences(MetadataReference.CreateFromStream(ms));
}
// Get the consuming assembly
Assembly assembly;
using (MemoryStream ms = new MemoryStream())
{
EmitResult result = compilation.Emit(ms);
ms.Seek(0, SeekOrigin.Begin);
byte[] assemblyBytes = ms.ToArray();
assembly = Assembly.Load(assemblyBytes);
}
// Call the consuming assembly
Type barType = assembly.GetExportedTypes().First(t => t.Name.StartsWith("Bar", StringComparison.Ordinal));
MethodInfo bazMethod = barType.GetMethod("Baz");
object bar = Activator.CreateInstance(barType);
object obj = globals.Factory.Get();
bazMethod.Invoke(bar, new []{ obj }); // The exception bubbles up and gets thrown here
}
private Assembly OnAssemblyResolve(object sender, ResolveEventArgs args)
{
if (_scriptAssembly != null && args.Name == _scriptAssembly.FullName)
{
// Return the dynamically compiled script assembly if given it name
return _scriptAssembly;
}
return null;
}
}
}