c#动态类型,及动态对象的创建,合并2个对象,map实例

时间:2021-10-02 05:27:18

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。

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
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:

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
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

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
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:

?
1
2
3
4
5
6
7
8
9
10
11
12
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:

?
1
2
3
4
5
6
7
8
9
[{"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:

?
1
{ "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服务器之家。