刚发现这个老歌…
要在没有动态LINQ库的情况下执行此操作，您只需要以下代码。这涵盖了最常见的场景，包括嵌套属性。
要使其工作，
IEnumerable<T>您可以添加一些可通过的包装器方法
AsQueryable-但以下代码是
expression所需的核心逻辑。
public static IOrderedQueryable<T> OrderBy<T>( this IQueryable<T> source, string property){ return ApplyOrder<T>(source, property, "OrderBy");}public static IOrderedQueryable<T> OrderByDescending<T>( this IQueryable<T> source, string property){ return ApplyOrder<T>(source, property, "OrderByDescending");}public static IOrderedQueryable<T> ThenBy<T>( this IOrderedQueryable<T> source, string property){ return ApplyOrder<T>(source, property, "ThenBy");}public static IOrderedQueryable<T> ThenByDescending<T>( this IOrderedQueryable<T> source, string property){ return ApplyOrder<T>(source, property, "ThenByDescending");}static IOrderedQueryable<T> ApplyOrder<T>( IQueryable<T> source, string property, string methodName) { string[] props = property.Split('.'); Type type = typeof(T); Parameterexpression arg = expression.Parameter(type, "x"); expression expr = arg; foreach(string prop in props) { // use reflection (not ComponentModel) to mirror LINQ PropertyInfo pi = type.GetProperty(prop); expr = expression.Property(expr, pi); type = pi.PropertyType; } Type delegateType = typeof(Func<,>).MakeGenericType(typeof(T), type); Lambdaexpression lambda = expression.Lambda(delegateType, expr, arg); object result = typeof(Queryable).GetMethods().Single( method => method.Name == methodName && method.IsGenericMethodDefinition && method.GetGenericArguments().Length == 2 && method.GetParameters().Length == 2) .MakeGenericMethod(typeof(T), type) .Invoke(null, new object[] {source, lambda}); return (IOrderedQueryable<T>)result;}编辑：如果要与之混合使用，它会变得更加有趣
dynamic-尽管请注意，这
dynamic仅适用于LINQ-to-
Objects（ORM等的表达树不能真正表示
dynamic查询-
Memberexpression不支持它）。但是这是使用LINQ-to-
Objects的一种方法。注意，之所以选择
Hashtable是由于有利的锁定语义：
using Microsoft.CSharp.RuntimeBinder;using System;using System.Collections;using System.Collections.Generic;using System.Dynamic;using System.Linq;using System.Runtime.CompilerServices;static class Program{ private static class AccessorCache { private static readonly Hashtable accessors = new Hashtable(); private static readonly Hashtable callSites = new Hashtable(); private static CallSite<Func<CallSite, object, object>> GetCallSiteLocked( string name) { var callSite = (CallSite<Func<CallSite, object, object>>)callSites[name]; if(callSite == null) { callSites[name] = callSite = CallSite<Func<CallSite, object, object>> .Create(Binder.GetMember( CSharpBinderFlags.None,name,typeof(AccessorCache), new CSharpArgumentInfo[] { CSharpArgumentInfo.Create( CSharpArgumentInfoFlags.None, null)})); } return callSite; } internal static Func<dynamic,object> GetAccessor(string name) { Func<dynamic, object> accessor = (Func<dynamic, object>)accessors[name]; if (accessor == null) { lock (accessors ) { accessor = (Func<dynamic, object>)accessors[name]; if (accessor == null) { if(name.IndexOf('.') >= 0) { string[] props = name.Split('.'); CallSite<Func<CallSite, object, object>>[] arr= Array.ConvertAll(props, GetCallSiteLocked); accessor = target => { object val = (object)target; for (int i = 0; i < arr.Length; i++) { var cs = arr[i]; val = cs.Target(cs, val); } return val; }; } else { var callSite = GetCallSiteLocked(name); accessor = target => { return callSite.Target(callSite, (object)target); }; } accessors[name] = accessor; } } } return accessor; } } public static IOrderedEnumerable<dynamic> OrderBy( this IEnumerable<dynamic> source, string property) { return Enumerable.OrderBy<dynamic, object>( source, AccessorCache.GetAccessor(property), Comparer<object>.Default); } public static IOrderedEnumerable<dynamic> OrderByDescending( this IEnumerable<dynamic> source, string property) { return Enumerable.OrderByDescending<dynamic, object>( source, AccessorCache.GetAccessor(property), Comparer<object>.Default); } public static IOrderedEnumerable<dynamic> ThenBy( this IOrderedEnumerable<dynamic> source, string property) { return Enumerable.ThenBy<dynamic, object>( source, AccessorCache.GetAccessor(property), Comparer<object>.Default); } public static IOrderedEnumerable<dynamic> ThenByDescending( this IOrderedEnumerable<dynamic> source, string property) { return Enumerable.ThenByDescending<dynamic, object>( source, AccessorCache.GetAccessor(property), Comparer<object>.Default); } static void Main() { dynamic a = new ExpandoObject(), b = new ExpandoObject(), c = new ExpandoObject(); a.X = "abc"; b.X = "ghi"; c.X = "def"; dynamic[] data = new[] { new { Y = a }, new { Y = b }, new { Y = c } }; var ordered = data.OrderByDescending("Y.X").ToArray(); foreach (var obj in ordered) { Console.WriteLine(obj.Y.X); } }}
