将PropertyInfo转换为Func<>；代表

不确定你想要实现什么，因为即使是动态或匿名对象，你也需要知道Key字段的名称，但这样的东西会对你所说的方法（错误处理和消除）起到作用：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Dynamic;
namespace ConsoleApplication11
{
    class KeyAttribute : Attribute
    {
    }
    public class Example
    {
        [Key]
        public Guid FirstKey { get; set; }
        [Key]
        public Guid SecondKey { get; set; }
        public int UnimportantField { get; set; }
    }
    static class Program
    {
        static void Main(string[] args)
        {
            Example e = new Example()
            {
                FirstKey = Guid.NewGuid(),
                SecondKey = Guid.NewGuid()
            };
            var func = GetKeyFunction<Example>();
            var key = func(e);
            Console.WriteLine(key.FirstKey);
            Console.WriteLine(key.SecondKey);
        }
        public static Func<T, dynamic> GetKeyFunction<T>()
        {
            return (t) =>
                {
                    var dyn = (IDictionary<string, object>)new ExpandoObject();
                    foreach (var p in GetKeyProperties(typeof(T)))
                    {
                        dyn.Add(p.Name, p.GetValue(t));
                    }
                    return dyn;
                };
        }
        public static IEnumerable<PropertyInfo> GetKeyProperties(Type t)
        {
            PropertyInfo[] properties = t.GetProperties();
            return properties.Where(p => p.GetCustomAttributes<KeyAttribute>().Any());
        }
    }
}

编辑

在阅读了一些注释后，您可能会对这种方法产生兴趣，并将Equals和GetHashCode实现添加到动态对象中（该实现假设键字段的名称在等式中很重要）。感觉有太多的代码和动态来确定对象的相等性，但。。。

与上面的代码相同，但有一个助手类来确定字典相等性和哈希代码。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Dynamic;
namespace ConsoleApplication11
{
    class KeyAttribute : Attribute
    {
    }
    public class Example
    {
        [Key]
        public Guid FirstKey { get; set; }
        [Key]
        public Guid SecondKey { get; set; }
        public int UnimportantField { get; set; }
    }
    static class Program
    {
        static void Main(string[] args)
        {
            Example e = new Example()
            {
                FirstKey = Guid.NewGuid(),
                SecondKey = Guid.NewGuid(),
                UnimportantField = 0
            };
            var func = GetKeyFunction<Example>();
            var key = func(e);
            Console.WriteLine(key.FirstKey);
            Console.WriteLine(key.SecondKey);
            Console.WriteLine(key.Equals(key));
            Console.WriteLine(key.GetHashCode());
            Example e2 = new Example()
            {
                FirstKey = Guid.NewGuid(),
                SecondKey = Guid.NewGuid(),
                UnimportantField = 1
            };
            var key2 = func(e2);
            Console.WriteLine(key2.FirstKey);
            Console.WriteLine(key2.SecondKey);
            Console.WriteLine(key.Equals(key2));
            Console.WriteLine(key2.GetHashCode());
        }
        public static Func<T, dynamic> GetKeyFunction<T>()
        {
            return (t) =>
                {
                    var dyn = (IDictionary<string, object>)new ExpandoObject();
                    foreach (var p in GetKeyProperties(typeof(T)))
                    {
                        dyn.Add(p.Name, p.GetValue(t));
                    }
                    dyn.Add("Equals", (Func<object, bool>)((o) => 
                        {
                            var comparer = new DictionaryComparer<string,object>();
                            return comparer.Equals(dyn as IDictionary<string,object>, o as IDictionary<string,object>);
                        }
                        ));
                    dyn.Add("GetHashCode", (Func<int>)(() =>
                        {
                            var comparer = new DictionaryComparer<string, object>();
                            return comparer.GetHashCode(dyn as IDictionary<string, object>);
                        }
                        ));
                    return dyn;
                };
        }
        public static IEnumerable<PropertyInfo> GetKeyProperties(Type t)
        {
            PropertyInfo[] properties = t.GetProperties();
            return properties.Where(p => p.GetCustomAttributes<KeyAttribute>().Any());
        }
    }
    public class DictionaryComparer<TKey, TValue> : EqualityComparer<IDictionary<TKey, TValue>>
    {
        public DictionaryComparer()
        {
        }
        public override bool Equals(IDictionary<TKey, TValue> x, IDictionary<TKey, TValue> y)
        {
            // early-exit checks
            if (object.ReferenceEquals(x, y))
                return true;
            if (null == x || y == null)
                return false;
            if (x.Count != y.Count)
                return false;
            // check keys are the same
            foreach (TKey k in x.Keys)
                if (!y.ContainsKey(k))
                    return false;
            // check values are the same
            foreach (TKey k in x.Keys)
            {
                TValue v = x[k];
                if (object.ReferenceEquals(v, null))
                    return object.ReferenceEquals(y[k], null);

                if (!v.Equals(y[k]))
                    return false;
            }
            return true;
        }    
        public override int GetHashCode(IDictionary<TKey, TValue> obj)
        {
            if (obj == null)
                return 0;
            int hash = 0;
            foreach (KeyValuePair<TKey, TValue> pair in obj)
            {
                int key = pair.Key.GetHashCode(); // key cannot be null
                int value = pair.Value != null ? pair.Value.GetHashCode() : 0;
                hash ^= ShiftAndWrap(key, 2) ^ value;
            }
            return hash;
        }
        private static int ShiftAndWrap(int value, int positions)
        {
            positions = positions & 0x1F;

            // Save the existing bit pattern, but interpret it as an unsigned integer. 
            uint number = BitConverter.ToUInt32(BitConverter.GetBytes(value), 0);
            // Preserve the bits to be discarded. 
            uint wrapped = number >> (32 - positions);
            // Shift and wrap the discarded bits. 
            return BitConverter.ToInt32(BitConverter.GetBytes((number << positions) | wrapped), 0);
        }
    }
}