使用C#动态编译代码

Question

如何编写C#代码来编译和运行动态生成的C#代码.周围有例子吗？

我所追求的是动态构建一个C#类(或类)并在运行时运行它们.我希望生成的类与其他非动态的C#类进行交互.

我见过生成exe或dll文件的例子.我不是在那之后,我只是想让它在内存中编译一些C#代码然后运行它.例如,

所以这里有一个非动态的类,它将在我的C#程序集中定义,并且只会在编译时更改,

public class NotDynamicClass
{
    private readonly List<string> values = new List<string>();

    public void AddValue(string value)
    {
        values.Add(value);
    }

    public void ProcessValues()
    {
        // do some other stuff with values
    }
}

这是我的动态类.我的C#代码将生成此类并运行它,

public class DynamicClass
{
    public static void Main()
    {
        NotDynamicClass class = new NotDynamicClass();

        class.AddValue("One");
        class.AddValue("two");
    }
}

结果是,最后我的非动态代码将调用ProcessValues,它会做一些其他的事情.动态代码的要点是允许我们或客户端向软件添加自定义逻辑.

谢谢.

Answer 1

两种可能性:

1. Reflection.Emit的
2. System.CodeDom.Compiler

更新:

正如评论部分中的请求,这是一个完整的示例,说明了Reflection.Emit的用法,以动态构建一个类并向其添加一个静态方法:

using System;
using System.Collections.Generic;
using System.Reflection;
using System.Reflection.Emit;

public class NotDynamicClass
{
    private readonly List<string> values = new List<string>();

    public void AddValue(string value)
    {
        values.Add(value);
    }

    public void ProcessValues()
    {
        foreach (var item in values)
        {
            Console.WriteLine(item);
        }
    }
}

class Program
{
    public static void Main()
    {
        var assemblyName = new AssemblyName("DynamicAssemblyDemo");
        var assemblyBuilder = AppDomain.CurrentDomain.DefineDynamicAssembly(assemblyName, AssemblyBuilderAccess.Run);
        var moduleBuilder = assemblyBuilder.DefineDynamicModule(assemblyName.Name, false);
        var typeBuilder = moduleBuilder.DefineType("DynamicClass", TypeAttributes.Public);

        var methodBuilder = typeBuilder.DefineMethod(
            "Main",
            MethodAttributes.Public | MethodAttributes.Static,
            null,
            new Type[0]
        );

        var il = methodBuilder.GetILGenerator();
        var ctor = typeof(NotDynamicClass).GetConstructor(new Type[0]);
        var addValueMi = typeof(NotDynamicClass).GetMethod("AddValue");
        il.Emit(OpCodes.Newobj, ctor);
        il.Emit(OpCodes.Stloc_0);
        il.DeclareLocal(typeof(NotDynamicClass));
        il.Emit(OpCodes.Ldloc_0);
        il.Emit(OpCodes.Ldstr, "One");
        il.Emit(OpCodes.Callvirt, addValueMi);
        il.Emit(OpCodes.Ldloc_0);
        il.Emit(OpCodes.Ldstr, "Two");
        il.Emit(OpCodes.Callvirt, addValueMi);
        il.Emit(OpCodes.Ldloc_0);
        il.Emit(OpCodes.Callvirt, typeof(NotDynamicClass).GetMethod("ProcessValues"));
        il.Emit(OpCodes.Ret);
        var t = typeBuilder.CreateType();
        var mi = t.GetMethod("Main");
        mi.Invoke(null, new object[0]);
    }
}

您可以在非NotDynamicClass方法中放置断点,并查看它们是如何被调用的.

更新2:

以下是CodeDom编译器的示例:

using System;
using System.CodeDom.Compiler;
using System.Collections.Generic;
using Microsoft.CSharp;

public class NotDynamicClass
{
    private readonly List<string> values = new List<string>();

    public void AddValue(string value)
    {
        values.Add(value);
    }

    public void ProcessValues()
    {
        foreach (var item in values)
        {
            Console.WriteLine(item);
        }
    }
}

class Program
{
    public static void Main()
    {
        var provider = CSharpCodeProvider.CreateProvider("c#");
        var options = new CompilerParameters();
        var assemblyContainingNotDynamicClass = Path.GetFileName(Assembly.GetExecutingAssembly().Location);
        options.ReferencedAssemblies.Add(assemblyContainingNotDynamicClass);
        var results = provider.CompileAssemblyFromSource(options, new[] 
        { 
@"public class DynamicClass
{
    public static void Main()
    {
        NotDynamicClass @class = new NotDynamicClass();
        @class.AddValue(""One"");
        @class.AddValue(""Two"");
        @class.ProcessValues();
    }
}"
        });
        if (results.Errors.Count > 0)
        {
            foreach (var error in results.Errors)
            {
                Console.WriteLine(error);
            }
        }
        else
        {
            var t = results.CompiledAssembly.GetType("DynamicClass");
            t.GetMethod("Main").Invoke(null, null);
        }
    }
}