Roslyn引擎自2014年开源至今这么久，一直没怎么了解过，虽然VS2015早就集成了它。以前老一套的动态编译方法在 .NET Core中似乎不再支持了，很多方法都是未实现的。下面就介绍如何在.NET Core环境中使用Roslyn进行动态编译。话不多说，Talk is cheap, show me the code.首先是安装nuget包Install-Package Microsoft.CodeAnalysis.CSharp 接下来是我们需要动态编译和执行的代码：// 表达式树
SyntaxTree syntaxTree = CSharpSyntaxTree.ParseText(@"
using System;
namespace RoslynCompileSample
{
public class Writer
{
public void Write(string message)
{
Console.WriteLine(message);
}
}
}");紧接着是创建编译对象：// 随机程序集名称
string assemblyName = Path.GetRandomFileName();
// 元数据引用
MetadataReference[] references = new MetadataReference[]
{
MetadataReference.CreateFromFile(typeof(object).Assembly.Location),
MetadataReference.CreateFromFile(typeof(Enumerable).Assembly.Location)
};
// 创建编译对象
CSharpCompilation compilation = CSharpCompilation.Create(
assemblyName,
syntaxTrees: new[] { syntaxTree },
references: references,
options: new CSharpCompilationOptions(OutputKind.DynamicallyLinkedLibrary));然后是编译：using (var ms = new MemoryStream())
{
// 将编译后的IL代码放入内存中
EmitResult result = compilation.Emit(ms);
// 编译失败，提示
if (!result.Success)
{
IEnumerable<Diagnostic> failures = result.Diagnostics.Where(diagnostic =>
diagnostic.IsWarningAsError
diagnostic.Severity == DiagnosticSeverity.Error);
foreach (Diagnostic diagnostic in failures)
{
Console.Error.WriteLine("{0}: {1}", diagnostic.Id, diagnostic.GetMessage());
}
}
else
{
// 编译成功则从内存中加载程序集
ms.Seek(0, SeekOrigin.Begin);
Assembly assembly = Assembly.Load(ms.ToArray());
}
}最后则是调用：// 反射获取程序集中 的类
Type type = assembly.GetType("RoslynCompileSample.Writer");
// 创建该类的实例
object obj = Activator.CreateInstance(type);
// 通过反射方式调用类中的方法。（Hello World 便是我们传入方法的参数）
type.InvokeMember("Write",
BindingFlags.Default
BindingFlags.InvokeMethod,
null,
obj,
new object[] { "Hello World" });最后咱们可以封装一个方法，以便于调用：/// <summary>
/// 动态编译
/// </summary>
/// <param name="code">需要动态编译的代码</param>
/// <returns>动态生成的程序集</returns>
public static Assembly GenerateAssemblyFromCode(string code)
{
Assembly assembly = null;
// 丛代码中转换表达式树
SyntaxTree syntaxTree = CSharpSyntaxTree.ParseText(code);
// 随机程序集名称
string assemblyName = Path.GetRandomFileName();
// 引用
var references = AppDomain.CurrentDomain.GetAssemblies().Select(x => MetadataReference.CreateFromFile(x.Location));
// 创建编译对象
CSharpCompilation compilation = CSharpCompilation.Create(assemblyName, new[] { syntaxTree }, references, new CSharpCompilationOptions(OutputKind.DynamicallyLinkedLibrary));
using (var ms = new MemoryStream())
{
// 将编译好的IL代码放入内存流
EmitResult result = compilation.Emit(ms);
// 编译失败，提示
if (!result.Success)
{
IEnumerable<Diagnostic> failures = result.Diagnostics.Where(diagnostic =>
diagnostic.IsWarningAsError
diagnostic.Severity == DiagnosticSeverity.Error);
foreach (Diagnostic diagnostic in failures)
{
Console.Error.WriteLine("{0}: {1}", diagnostic.Id, diagnostic.GetMessage());
}
}
else
{
// 编译成功，从内存中加载编译好的程序集
ms.Seek(0, SeekOrigin.Begin);
assembly = Assembly.Load(ms.ToArray());
}
}
return assembly;
}}