詳解c#動態類型與動態物件的建立,合併2個物件,map實例程式碼

下面小編就為大家帶來一篇c#動態型別,及動態物件的建立,合併2個物件,map實例。小編覺得蠻不錯的，現在就分享給大家，也給大家做個參考。一起跟隨小編過來看看吧

經常會遇到這樣的情況，我們在回應客戶端請求的資料的時候需要對資料進行處理，例如資料庫中的資料是int型，它可能表示某個枚舉，或者其它的邏輯意義（資料庫這樣的設計可能是從資料安全性、儲存量上等角度來考慮），但是客戶端顯示的時候需要是它具體的意義。

這時候我們的處理方式一般都是2中的，如果邏輯不複雜，且單一的話，直接修改sql語句就能處理好資料來源，這時候程式碼裡面不需要處理什麼。

但是如果邏輯複稍許複雜或判斷的情況有很多分支，我們只好從程式碼角度來處理了。單一物件還好，多個物件例如是個list,那就要循環對某個物件的欄位進行XXX了。

進而衍生出了這就出現了DTO，Arg的中間對象，當然，我個人是很喜歡這樣的設計的，但是某些時候也會偷懶不想寫（多半情況我直接寫代碼生器批量生產），例如在測試的時候，在接私活的時候，在演示的時候，只為快速呈現想要的效果都懶得去屑，是的，你會說市面上不是有很多的map庫，例如automap，tinymap，甚至json.net裡面的動態特性重寫，方法當然很多，但用一個大輪子來費力搞這麼個小事，我覺得劃不來。而且輪子越來越大它要幹的事越多，我可不想搞的那麼複雜，嗯，就是這樣，寫了個。

具體的程式碼貼到下面，如果看明白，會很方便的擴充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
{
}

下面我們測試一個：

 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);

您可以重新建構帶參數的特性或修改injectAct對象，改成適合自己的

下面寫個測試，改成表達式樹最好了，先上一個碼

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>
    /// 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;
    }
  }
}

##測試一下：

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" }

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