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trydex
Asked:2020-12-11 01:48:28 +0000 UTC2020-12-11 01:48:28 +0000 UTC

如何从 Roslyn 的入口点执行代码

  • 772

需要做的是允许用户在我的服务器上执行 C# 代码（类似于dotnetfiddle.net）。Asp.net 核心应用程序。

有一种方法效果很好：

public static async Task<ScriptState<object>> ExecuteScriptAsync(string code, IEnumerable<Assembly> references,
    IEnumerable<string> usings)
{
    var options = ScriptOptions.Default.WithReferences(references).WithImports(usings);

    return await CSharpScript.RunAsync(code, options);
}

该方法的问题ExecuteScript是它将不再执行这样的代码：

class Program 
{
    public static void Main() 
    {
        throw new System.Exception();   
    }
}

如何使代码像在控制台应用程序中一样运行，即 方法Main是切入点？

更新

找到了这段代码。它可以工作，但是如果您添加到脚本中，它会因错误“当前上下文中不存在Console.WriteLine("hi")该名称”而中断。Console

var script = @"using System;
                public static class Program
                {
                    public static int Main(string[] args)
                    {
                        var x = 7 * 8;
                        return x;
                    }
                }";

var assemblyPath = Path.GetDirectoryName(typeof(object).Assembly.Location);
var refs = new List<PortableExecutableReference>
{
    MetadataReference.CreateFromFile(typeof(object).Assembly.Location),
    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")),
    MetadataReference.CreateFromFile(Assembly.GetEntryAssembly().Location)
};

// Parse the script to a SyntaxTree
var syntaxTree = CSharpSyntaxTree.ParseText(script);
var options = new CSharpCompilationOptions(OutputKind.ConsoleApplication);
// Compile the SyntaxTree to a CSharpCompilation
var compilation = CSharpCompilation.Create("Script",
    new[] { syntaxTree },
    refs,
    new CSharpCompilationOptions(
        OutputKind.ConsoleApplication,
        optimizationLevel: OptimizationLevel.Release,
        assemblyIdentityComparer: DesktopAssemblyIdentityComparer.Default));

//CodeDomProvider codeDomProvider = new CodeDomProvider();
using (var outputStream = new MemoryStream())
using (var pdbStream = new MemoryStream())
{
    // Emit assembly to streams.
    var result = compilation.Emit(outputStream, pdbStream);
    if (!result.Success)
    {
        return;
    }

    // Load the emitted assembly.
    var assembly = Assembly.Load(outputStream.ToArray(), pdbStream.ToArray());

    // Invoke the entry point.
    var x = assembly.EntryPoint.Invoke(null, null);
c#

1 个回答

  1. Best Answer

    Assembly.Load，尤其是从字节数组中，是一个非常糟糕的主意，因为它无法随后从内存中卸载程序集，即 在服务器应用程序中工作时，内存迟早会耗尽，并且必须重新启动服务器。另外，您如何限制您运行的代码的权限，以使其不会使您的系统崩溃？如果你的目标是 .NET Core，则应用域不可用。更正确的做法是将代码编译成文件，并在权限有限的用户下的新进程中运行，并截取其输出：

    using System;
using System.Collections.Generic;
using System.IO;
using System.Diagnostics;
using System.Reflection;
using Microsoft.CodeAnalysis;
using Microsoft.CodeAnalysis.CSharp;

namespace RoslynTest
{
    class Program
    {
        static void RunScript()
        {
            var script = @"using System;
                public static class Program
                {
                    public static int Main(string[] args)
                    {
                        var x = 7 * 8;
                        Console.WriteLine(x.ToString());
                        return x;
                    }
                }";

            var assemblyPath = Path.GetDirectoryName(typeof(object).Assembly.Location);
            var refs = new List<PortableExecutableReference>
            {
                 MetadataReference.CreateFromFile(typeof(object).Assembly.Location),
                 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")),
                MetadataReference.CreateFromFile(Assembly.GetEntryAssembly().Location)
            };


            // Parse the script to a SyntaxTree
            var syntaxTree = CSharpSyntaxTree.ParseText(script);
            var options = new CSharpCompilationOptions(OutputKind.ConsoleApplication);
            // Compile the SyntaxTree to a CSharpCompilation
            var compilation = CSharpCompilation.Create("Script",
                new[] { syntaxTree },
                refs,
                new CSharpCompilationOptions(
                    OutputKind.ConsoleApplication,
                    optimizationLevel: OptimizationLevel.Release,                    
                    assemblyIdentityComparer: DesktopAssemblyIdentityComparer.Default)
                    );

            var result = compilation.Emit("script.exe");
            if (!result.Success)
            {
                throw new ApplicationException("Cannot compile script");
            }            

            ProcessStartInfo psi = new ProcessStartInfo();
            psi.FileName = "script.exe";
            psi.UseShellExecute = false;
            psi.RedirectStandardOutput = true;
            psi.RedirectStandardInput = true; 
            psi.UserName = "Vasya";
            psi.Password = "123";

            var process = new Process();
            using (process)
            {
                process.StartInfo = psi;                
                process.Start();

                while (!process.StandardOutput.EndOfStream)
                {
                    string res = process.StandardOutput.ReadLine();                    
                    Console.WriteLine(res);
                }
            }
        }
    }
}

    该代码是为 .NET Framework / Windows 量身定制的，但我认为为 .NET Core 重新制作它并不难，因为使用的所有库都在 .NET Standard 中。从 .NET Core 2.1 开始，以不同用户身份运行进程应该可以在所有操作系统上的 .NET Core 中运行。

    笔记。.NET Core 3.0 引入了从内存中卸载程序集的功能，但这仍然不能解决安全问题。

    • 3

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