详解c#动态类型和动态对象的创建,合并2个对象,map实例代码
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2022-05-05 13:21:42
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下面小编就为大家带来一篇c#动态类型,及动态对象的创建,合并2个对象,map实例。小编觉得挺不错的,现在就分享给大家,也给大家做个参考。一起跟随小编过来看看吧
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*来费力搞这么个小事,我觉得划不来。且*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" }
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