经常会遇到这样的情况，我们在响应客户端请求的数据的时候需要对数据进行处理，比如数据库中的数据是int型，它可能表示某个枚举，或者其它的逻辑意义（数据库这样的设计可能是从数据安全性、存储量上等角度考虑），但是客户端显示的时候需要是它具体的意义。
这个时候我们的处理方式一般都是2中的，如果逻辑不复杂，且单一的话，直接修改sql语句就能处理好数据源，这个时候代码里面不需要处理什么。
但是如果逻辑复稍许复杂或者判断的情况有很多分支，我们不得不从代码角度来处理了。单个对象还好，多个对象比如是个list<T>,那就要循环对某个对象的字段进行XXX了。
进而衍生出了这就出现了DTO，Arg的中间对象，当然，我个人是很喜欢这样的设计的，但是某些时候也会偷懒不想写（多半情况我直接写代码生器批量生产），比如在测试的时候，在接私活的时候，在演示的时候，只为快速呈现想要的效果 都懒得去屑，是的，你会说市面上不是有很多的map库，比如automap，tinymap，甚至json.net里面的动态特性重写，方法当然很多，但用一个大轮子来费力搞这么个小事，我觉得划不来。且轮子越来越大它要干的事越多，我可不想搞的那么复杂，嗯，就是这样，写了个。
具体的代码贴到下面，如果看明白，会很方便的扩展了或修改成自己想要的效果。
using System.Dynamic;using System.Reflection;using System.Collections.Concurrent;private static readonly ConcurrentDictionary<RuntimeTypeHandle, PropertyInfo[]> DynamicObjectProperties = new ConcurrentDictionary<RuntimeTypeHandle, PropertyInfo[]>();private IDictionary<string, Object> ToDynamicResult<T>(T classobj, Func<string, object, object> injectAct) where T : IInjectClass, new(){ var type = typeof(T); var key = type.TypeHandle; var dynamicResult = new ExpandoObject() as IDictionary<string, Object>; PropertyInfo[] queryPts = null; DynamicObjectProperties.TryGetValue(key, out queryPts); if (queryPts == null) { queryPts = type.GetProperties(); DynamicObjectProperties.TryAdd(key, queryPts); } foreach (var p in queryPts) { var attributes = p.GetCustomAttributes(typeof(IngorePropertyAttribute), true); var columnMapping = attributes.FirstOrDefault(); if (columnMapping != null) continue; var _name = p.Name; var _value = p.GetValue(classobj, null); object _tempvalue = _value; if (injectAct != null) _tempvalue = injectAct.Invoke(_name, _value); //var value = Convert.ChangeType(value，typeof(string)); dynamicResult.Add(p.Name, _tempvalue); } return dynamicResult;}/// <summary>/// 支持动态输出的对象接口/// </summary>public interface IInjectClass{}/// <summary>/// 动态输出时忽略此标记的属性/// </summary>public class IngorePropertyAttribute : Attribute{}下面我们测试一个：
public class kk : IInjectClass { public string aa { get; set; } public int bb { get; set; } [IngoreProperty] public bool cc { get; set; } public DateTime dd { get; set; } }kk ist = new kk();ist.aa = "aaa";ist.bb = 123;ist.cc = false;ist.dd = DateTime.Now;var tt = ToDynamicResult<kk>(ist, (k, v) =>{ if (k != "aa") return v; return v + "(改变了哦)";});var json = Tools.JsonUtils.JsonSerializer(tt);json = json + "<br /><br />" + Tools.JsonUtils.JsonSerializer(ToDynamicResult<kk>( new kk { aa = "test", bb = 789, cc = true, dd = DateTime.Now.AddDays(2) }, null));Response.Write(json);您可以重新构造带参数的特性或者修改injectAct对象，改成适合自己的
下面写个测试，改成表达式树最好了，先上个码
using System;using System.Linq;using System.Dynamic;using System.Reflection;using System.Linq.Expressions;using System.Collections.Generic;using System.Collections.Concurrent;namespace Tools{ public class Class2Map { private static readonly ConcurrentDictionary<RuntimeTypeHandle, PropertyInfo[]> DynamicObjectProperties = new ConcurrentDictionary<RuntimeTypeHandle, PropertyInfo[]>(); private static PropertyInfo[] GetObjectProperties<T>() { var type = typeof(T); var key = type.TypeHandle; PropertyInfo[] queryPts = null; DynamicObjectProperties.TryGetValue(key, out queryPts); if (queryPts == null) { queryPts = type.GetProperties(); DynamicObjectProperties.TryAdd(key, queryPts); } return queryPts; } /// <summary> /// 单个对象映射 /// </summary> /// <typeparam name="T">类型</typeparam> /// <param name="source">实例</param> /// <param name="injectAct">map方法集</param> /// <returns>映射后的动态对象</returns> public static IDictionary<string, Object> DynamicResult<T>(T source, params MapCondition[] injectAct)//where T : ICustomMap { var queryPts = GetObjectProperties<T>(); var dynamicResult = new ExpandoObject() as IDictionary<string, Object>; foreach (var p in queryPts) { var attributes = p.GetCustomAttributes(typeof(IngoreProperty), true); if (attributes.FirstOrDefault() != null) continue; var _name = p.Name; //原来是属性名 var _value = p.GetValue(source, null); //原来的属性值 object _resultvalue = _value; //最终的映射值 if (injectAct != null) { string _tempname = null; var condition = injectAct.FirstOrDefault(x => x.Orginal == _name); if (CheckChangeInfo(condition, out _tempname)) { _resultvalue = condition.fn.Invoke(_value); dynamicResult.Add(_tempname ?? _name, _resultvalue); continue; } } //var value = Convert.ChangeType(value，typeof(string)); dynamicResult.Add(_name, _resultvalue); } return dynamicResult; } /// <summary> /// 合并2个对象 /// </summary> /// <typeparam name="TSource">对象1类型</typeparam> /// <typeparam name="TTarget">对象2类型</typeparam> /// <param name="s">对象1实例</param> /// <param name="t">对象2实例</param> /// <returns>合并后的动态对象</returns> public static IDictionary<string, Object> MergerObject<TSource, TTarget>(TSource s, TTarget t) { var targetPts = GetObjectProperties<TSource>(); PropertyInfo[] mergerPts = null; var _type = t.GetType(); mergerPts = _type.Name.Contains("<>") ? _type.GetProperties() : GetObjectProperties<TTarget>(); var dynamicResult = new ExpandoObject() as IDictionary<string, Object>; foreach (var p in targetPts) { var attributes = p.GetCustomAttributes(typeof(IngoreProperty), true); if (attributes.FirstOrDefault() != null) continue; dynamicResult.Add(p.Name, p.GetValue(s, null)); } foreach (var p in mergerPts) { var attributes = p.GetCustomAttributes(typeof(IngoreProperty), true); if (attributes.FirstOrDefault() != null) continue; dynamicResult.Add(p.Name, p.GetValue(t, null)); } return dynamicResult; } /// <summary> /// 合并2个对象 /// </summary> /// <typeparam name="TSource">对象1类型</typeparam> /// <typeparam name="TTarget">对象2类型</typeparam> /// <param name="s">对象1实例</param> /// <param name="t">对象2实例</param> /// <returns>合并后的动态对象</returns> public static List<IDictionary<string, Object>> MergerListObject<TSource, TTarget>(List<TSource> s, TTarget t) { var targetPts = GetObjectProperties<TSource>(); PropertyInfo[] mergerPts = null; var _type = t.GetType(); mergerPts = _type.Name.Contains("<>") ? _type.GetProperties() : GetObjectProperties<TTarget>(); var result = new List<IDictionary<string, Object>>(); s.ForEach(x => { var dynamicResult = new ExpandoObject() as IDictionary<string, Object>; foreach (var p in targetPts) { var attributes = p.GetCustomAttributes(typeof(IngoreProperty), true); if (attributes.FirstOrDefault() != null) continue; dynamicResult.Add(p.Name, p.GetValue(x, null)); } foreach (var p in mergerPts) { var attributes = p.GetCustomAttributes(typeof(IngoreProperty), true); if (attributes.FirstOrDefault() != null) continue; dynamicResult.Add(p.Name, p.GetValue(t, null)); } result.Add(dynamicResult); }); return result; } private static bool CheckChangeInfo(MapCondition condition, out string name) { name = null; bool result = condition != null && condition.fn != null && !string.IsNullOrWhiteSpace(condition.Orginal);//&& //!string.IsNullOrWhiteSpace(condition.NewName); if (result) { var temp = condition.NewName; name = (string.IsNullOrWhiteSpace(temp) || temp.Trim().Length == 0) ? null : temp; } return result; } }}测试一下：
List<KeyValue> kk = new List<KeyValue> { new KeyValue{key="aaa", value="111"}, new KeyValue{key="bbb", value="222"}, new KeyValue{key="ccc", value="333"}, new KeyValue{key="ddd", value="444"},};var result = Class2Map.MergerListObject<KeyValue, dynamic>(kk, new { p = "jon test" });var json = JsonUtils.JsonSerializer(result);Response.Write(json);输出如下：
[{"key":"aaa","value":"111","p":"jon test"},{"key":"bbb","value":"222","p":"jon test"},{"key":"ccc","value":"333","p":"jon test"},{"key":"ddd","value":"444","p":"jon test"}]var result = Class2Map.MergerObject<KeyValue, dynamic>( new KeyValue { key = "aaa", value = "111" }, new { p = "jon test" } );var json = JsonUtils.JsonSerializer(result);Response.Write(json);输出如下：
{ "key": "aaa", "value": "111", "p": "jon test" }以上这篇c#动态类型,及动态对象的创建,合并2个对象,map实例就是小编分享给大家的全部内容了，希望能给大家一个参考，也希望大家多多支持武林网。
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