将Expression<Func<BaseType、object>>转换为Expression<Func<DerievedType、object>>>

using System;
using System.Linq.Expressions;

public class BaseType { }
public class DerivedType : BaseType { }

public class ExpressionConverter : ExpressionVisitor
{
    protected override Expression VisitLambda<T>(Expression<T> node)
    {
        var parameters = node.Parameters.Select(p => Expression.Parameter(typeof(DerivedType), p.Name)).ToList();
        var body = Visit(node.Body);
        return Expression.Lambda(body, parameters);
    }
}

public class Program
{
    public static void Main()
    {
        Expression<Func<BaseType, object>> baseExpression = x => x.ToString();
        var converter = new ExpressionConverter();
        var derivedExpression = (Expression<Func<DerivedType, object>>)converter.Visit(baseExpression);

        Console.WriteLine(derivedExpression);
    }
}