将匿名类型转换为接口是我一直想做的事情，但不幸的是，当前的实现迫使您拥有该接口的实现。

围绕它的最佳解决方案是使用某种类型的动态代理为您创建实现。利用优秀的林父项目你可以替代

select new
{
  A = value.A,
  B = value.C + "_" + value.D
};

with

 select new DynamicObject(new
 {
   A = value.A,
   B = value.C + "_" + value.D
 }).CreateDuck<DummyInterface>();

不，匿名类型不能实现接口。摘自c#编程指南:

匿名类型是由一个或多个公共只读属性组成的类类型。不允许使用其他类型的类成员，如方法或事件。匿名类型不能强制转换为除对象以外的任何接口或类型。

这个问题的答案是否定的。但是您是否一直在研究模仿框架?我使用的是MOQ，但有数百万个MOQ，它们允许你在线实现/存根(部分或全部)接口。如。

public void ThisWillWork()
{
    var source = new DummySource[0];
    var mock = new Mock<DummyInterface>();

    mock.SetupProperty(m => m.A, source.Select(s => s.A));
    mock.SetupProperty(m => m.B, source.Select(s => s.C + "_" + s.D));

    DoSomethingWithDummyInterface(mock.Object);
}

最好的解决方案就是不要使用匿名类。

public class Test
{
    class DummyInterfaceImplementor : IDummyInterface
    {
        public string A { get; set; }
        public string B { get; set; }
    }

    public void WillThisWork()
    {
        var source = new DummySource[0];
        var values = from value in source
                     select new DummyInterfaceImplementor()
                     {
                         A = value.A,
                         B = value.C + "_" + value.D
                     };

        DoSomethingWithDummyInterface(values.Cast<IDummyInterface>());

    }

    public void DoSomethingWithDummyInterface(IEnumerable<IDummyInterface> values)
    {
        foreach (var value in values)
        {
            Console.WriteLine("A = '{0}', B = '{1}'", value.A, value.B);
        }
    }
}

注意，您需要将查询的结果强制转换为接口的类型。也许有更好的办法，但我找不到。

使用Roslyn，您可以动态地创建一个继承自接口(或抽象类)的类。

我使用以下代码从抽象类创建具体类。

在本例中，AAnimal是一个抽象类。

var personClass = typeof(AAnimal).CreateSubclass("Person");

然后你可以实例化一些对象:

var person1 = Activator.CreateInstance(personClass);
var person2 = Activator.CreateInstance(personClass);

毫无疑问，这并不适用于所有情况，但这应该足以让你开始:

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

namespace Publisher
{
    public static class Extensions
    {
        public static Type CreateSubclass(this Type baseType, string newClassName, string newNamespace = "Magic")
        {
            //todo: handle ref, out etc.
            var concreteMethods = baseType
                                    .GetMethods()
                                    .Where(method => method.IsAbstract)
                                    .Select(method =>
                                    {
                                        var parameters = method
                                                            .GetParameters()
                                                            .Select(param => $"{param.ParameterType.FullName} {param.Name}")
                                                            .ToString(", ");

                                        var returnTypeStr = method.ReturnParameter.ParameterType.Name;
                                        if (returnTypeStr.Equals("Void")) returnTypeStr = "void";

                                        var methodString = @$"
                                        public override {returnTypeStr} {method.Name}({parameters})
                                        {{
                                            Console.WriteLine(""{newNamespace}.{newClassName}.{method.Name}() was called"");
                                        }}";

                                        return methodString.Trim();
                                    })
                                    .ToList();

            var concreteMethodsString = concreteMethods
                                        .ToString(Environment.NewLine + Environment.NewLine);

            var classCode = @$"
            using System;

            namespace {newNamespace}
            {{
                public class {newClassName}: {baseType.FullName}
                {{
                    public {newClassName}()
                    {{
                    }}

                    {concreteMethodsString}
                }}
            }}
            ".Trim();

            classCode = FormatUsingRoslyn(classCode);


            /*
            var assemblies = new[]
            {
                MetadataReference.CreateFromFile(typeof(object).Assembly.Location),
                MetadataReference.CreateFromFile(baseType.Assembly.Location),
            };
            */

            var assemblies = AppDomain
                        .CurrentDomain
                        .GetAssemblies()
                        .Where(a => !string.IsNullOrEmpty(a.Location))
                        .Select(a => MetadataReference.CreateFromFile(a.Location))
                        .ToArray();

            var syntaxTree = CSharpSyntaxTree.ParseText(classCode);

            var compilation = CSharpCompilation
                                .Create(newNamespace)
                                .AddSyntaxTrees(syntaxTree)
                                .AddReferences(assemblies)
                                .WithOptions(new CSharpCompilationOptions(OutputKind.DynamicallyLinkedLibrary));

            using (var ms = new MemoryStream())
            {
                var result = compilation.Emit(ms);
                //compilation.Emit($"C:\\Temp\\{newNamespace}.dll");

                if (result.Success)
                {
                    ms.Seek(0, SeekOrigin.Begin);
                    Assembly assembly = Assembly.Load(ms.ToArray());

                    var newTypeFullName = $"{newNamespace}.{newClassName}";

                    var type = assembly.GetType(newTypeFullName);
                    return type;
                }
                else
                {
                    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());
                    }

                    return null;
                }
            }
        }

        public static string ToString(this IEnumerable<string> list, string separator)
        {
            string result = string.Join(separator, list);
            return result;
        }

        public static string FormatUsingRoslyn(string csCode)
        {
            var tree = CSharpSyntaxTree.ParseText(csCode);
            var root = tree.GetRoot().NormalizeWhitespace();
            var result = root.ToFullString();
            return result;
        }
    }
}

另一种选择是创建一个单独的、具体的实现类，在构造函数中接受lambdas。

public interface DummyInterface
{
    string A { get; }
    string B { get; }
}

// "Generic" implementing class
public class Dummy : DummyInterface
{
    private readonly Func<string> _getA;
    private readonly Func<string> _getB;

    public Dummy(Func<string> getA, Func<string> getB)
    {
        _getA = getA;
        _getB = getB;
    }

    public string A => _getA();

    public string B => _getB();
}

public class DummySource
{
    public string A { get; set; }
    public string C { get; set; }
    public string D { get; set; }
}

public class Test
{
    public void WillThisWork()
    {
        var source = new DummySource[0];
        var values = from value in source
                     select new Dummy // Syntax changes slightly
                     (
                         getA: () => value.A,
                         getB: () => value.C + "_" + value.D
                     );

        DoSomethingWithDummyInterface(values);

    }

    public void DoSomethingWithDummyInterface(IEnumerable<DummyInterface> values)
    {
        foreach (var value in values)
        {
            Console.WriteLine("A = '{0}', B = '{1}'", value.A, value.B);
        }
    }
}

如果你所要做的只是将DummySource转换为DummyInterface，那么在构造函数中使用一个DummySource并实现接口的类会更简单。

但是，如果您需要将许多类型转换为DummyInterface，这就少了很多。