如何使用Roslyn添加对内存流中编译的类型的引用？

Question

作为编译的输入,我有一个字符串,其中包含以下代码:

public class Person
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public int Age { get; set; }
    public string EmailAddress { get; set; }
}

我有以下代码,请注意评论[01].这里的目的是获取一个包含类的字符串(从this.Source组件的代码发出并发送到MemoryStream.

var assemblyPath = Path.GetDirectoryName(typeof(object).Assembly.Location);
var assemblyName = Guid.NewGuid().ToString();
var syntaxTrees = CSharpSyntaxTree.ParseText(this.Source);

// build references up
var references = new List<MetadataReference>();
//[01] references.Add("System.dll")); 

// set up compilation
var compilation = CSharpCompilation.Create(assemblyName)
    .WithOptions(new CSharpCompilationOptions(OutputKind.DynamicallyLinkedLibrary))
    .AddReferences(references)
    .AddSyntaxTrees(syntaxTrees);

// build the assembly
Assembly assembly;
using (var stream = new MemoryStream())
{
    // this is broked...
    EmitResult compileResult = compilation.Emit(stream);
    // [02] we get here, with diagnostic errors (check compileResult.Diagnostics)
    assembly = Assembly.Load(stream.GetBuffer());
}

在[02]我收到BadImageFormat异常时,在compileResult.Diagnostics中有以下内容:

[0]: warning CS8021: No value for RuntimeMetadataVersion found. No assembly containing System.Object was found nor was a value for RuntimeMetadataVersion specified through options.
[1]: (2,18): error CS0518: Predefined type 'System.Object' is not defined or imported
[2]: (4,16): error CS0518: Predefined type 'System.String' is not defined or imported
[3]: (4,40): error CS0518: Predefined type 'System.Void' is not defined or imported
[4]: (5,16): error CS0518: Predefined type 'System.String' is not defined or imported
[5]: (5,39): error CS0518: Predefined type 'System.Void' is not defined or imported
[6]: (6,16): error CS0518: Predefined type 'System.Int32' is not defined or imported
[7]: (6,31): error CS0518: Predefined type 'System.Void' is not defined or imported
[8]: (7,16): error CS0518: Predefined type 'System.String' is not defined or imported
[9]: (7,43): error CS0518: Predefined type 'System.Void' is not defined or imported
[10]: (2,18): error CS1729: 'object' does not contain a constructor that takes 0 arguments

如果我using System;在代码的开头添加一个,我会收到以下错误:

error CS0246: The type or namespace name 'System' could not be found (are you missing a using directive or an assembly reference?)

这让我相信我无法从我所在的位置访问System,这就是我在伪代码中存根的原因references.Add("System.dll"));.这显然不正确,但这是我的意图.

有关更多信息,此处的目的是动态创建生成类型的实例并为属性赋值.

将引用提供给编译器的正确方法是什么？

或者,是否有另一种方法来编译这样的类(来自字符串输入)？

Answer 1

调用AssemblyMetadata.CreateFromFile(path)方法，并传递typeof(object).Assembly.Location（或其他程序集）。