c#動(dòng)態(tài)類型,及動(dòng)態(tài)對(duì)象的創(chuàng)建,合并2個(gè)對(duì)象,map實(shí)例

來(lái)源：本站原創(chuàng)|時(shí)間：2020-01-10|欄目：C#教程|點(diǎn)擊：次

經(jīng)常會(huì)遇到這樣的情況，我們?cè)陧憫?yīng)客戶端請(qǐng)求的數(shù)據(jù)的時(shí)候需要對(duì)數(shù)據(jù)進(jìn)行處理，比如數(shù)據(jù)庫(kù)中的數(shù)據(jù)是int型，它可能表示某個(gè)枚舉，或者其它的邏輯意義（數(shù)據(jù)庫(kù)這樣的設(shè)計(jì)可能是從數(shù)據(jù)安全性、存儲(chǔ)量上等角度考慮），但是客戶端顯示的時(shí)候需要是它具體的意義。

這個(gè)時(shí)候我們的處理方式一般都是2中的，如果邏輯不復(fù)雜，且單一的話，直接修改sql語(yǔ)句就能處理好數(shù)據(jù)源，這個(gè)時(shí)候代碼里面不需要處理什么。

但是如果邏輯復(fù)稍許復(fù)雜或者判斷的情況有很多分支，我們不得不從代碼角度來(lái)處理了。單個(gè)對(duì)象還好，多個(gè)對(duì)象比如是個(gè)list<T>,那就要循環(huán)對(duì)某個(gè)對(duì)象的字段進(jìn)行XXX了。

進(jìn)而衍生出了這就出現(xiàn)了DTO，Arg的中間對(duì)象，當(dāng)然，我個(gè)人是很喜歡這樣的設(shè)計(jì)的，但是某些時(shí)候也會(huì)偷懶不想寫(xiě)（多半情況我直接寫(xiě)代碼生器批量生產(chǎn)），比如在測(cè)試的時(shí)候，在接私活的時(shí)候，在演示的時(shí)候，只為快速呈現(xiàn)想要的效果都懶得去屑，是的，你會(huì)說(shuō)市面上不是有很多的map庫(kù)，比如automap，tinymap，甚至json.net里面的動(dòng)態(tài)特性重寫(xiě)，方法當(dāng)然很多，但用一個(gè)大輪子來(lái)費(fèi)力搞這么個(gè)小事，我覺(jué)得劃不來(lái)。且輪子越來(lái)越大它要干的事越多，我可不想搞的那么復(fù)雜，嗯，就是這樣，寫(xiě)了個(gè)。

具體的代碼貼到下面，如果看明白，會(huì)很方便的擴(kuò)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>
/// 支持動(dòng)態(tài)輸出的對(duì)象接口
/// </summary>
public interface IInjectClass
{
}
/// <summary>
/// 動(dòng)態(tài)輸出時(shí)忽略此標(biāo)記的屬性
/// </summary>
public class IngorePropertyAttribute : Attribute
{
}

下面我們測(cè)試一個(gè)：

 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 + "(改變了哦)";
});

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);

您可以重新構(gòu)造帶參數(shù)的特性或者修改injectAct對(duì)象，改成適合自己的

下面寫(xiě)個(gè)測(cè)試，改成表達(dá)式樹(shù)最好了，先上個(gè)碼

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>
    /// 單個(gè)對(duì)象映射
    /// </summary>
    /// <typeparam name="T">類型</typeparam>
    /// <param name="source">實(shí)例</param>
    /// <param name="injectAct">map方法集</param>
    /// <returns>映射后的動(dòng)態(tài)對(duì)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;           //原來(lái)是屬性名
        var _value = p.GetValue(source, null); //原來(lái)的屬性值
        object _resultvalue = _value;      //最終的映射值

        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個(gè)對(duì)象
    /// </summary>
    /// <typeparam name="TSource">對(duì)象1類型</typeparam>
    /// <typeparam name="TTarget">對(duì)象2類型</typeparam>
    /// <param name="s">對(duì)象1實(shí)例</param>
    /// <param name="t">對(duì)象2實(shí)例</param>
    /// <returns>合并后的動(dòng)態(tài)對(duì)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個(gè)對(duì)象
    /// </summary>
    /// <typeparam name="TSource">對(duì)象1類型</typeparam>
    /// <typeparam name="TTarget">對(duì)象2類型</typeparam>
    /// <param name="s">對(duì)象1實(shí)例</param>
    /// <param name="t">對(duì)象2實(shí)例</param>
    /// <returns>合并后的動(dòng)態(tài)對(duì)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;
    }
  }
}

測(cè)試一下：

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);

輸出如下：

[{"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);

輸出如下：

{ "key": "aaa", "value": "111", "p": "jon test" }

以上這篇c#動(dòng)態(tài)類型,及動(dòng)態(tài)對(duì)象的創(chuàng)建,合并2個(gè)對(duì)象,map實(shí)例就是小編分享給大家的全部?jī)?nèi)容了，希望能給大家一個(gè)參考，也希望大家多多支持我們。

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