如何创建LINQ表达式树以选择匿名类型

using System.Linq.Expressions;
using System.Collections.Generic;

var anonymousType = new { Name = "", Age = 0 };

var parameter = Expression.Parameter(typeof(T), "x");
var nameProperty = Expression.Property(parameter, "Name");
var ageProperty = Expression.Property(parameter, "Age");

var newExpression = Expression.New(anonymousType.GetType().GetConstructor(new[] { typeof(string), typeof(int) }));

var nameBinding = Expression.Bind(anonymousType.GetType().GetProperty("Name"), nameProperty);
var ageBinding = Expression.Bind(anonymousType.GetType().GetProperty("Age"), ageProperty);

var memberInitExpression = Expression.MemberInit(newExpression, nameBinding, ageBinding);

var lambdaExpression = Expression.Lambda<Func<T, object>>(memberInitExpression, parameter);

var func = lambdaExpression.Compile();

var result = func(new { Name = "John", Age = 30 });