.NET Lamda 给匿名属性赋值 

 1 var _list = new { Name = "111111", Value = "AAAAA" };
 2 _list.Set();
 3 var myAnonInstance = new
 4 {
 5 FirstField = "Hello",
 6 AnotherField = 30,
 7 a = new { a = 111 }
 8 };
 9 Console.WriteLine(myAnonInstance);
10 myAnonInstance.a.Set(o => o.a, 2222);
11 myAnonInstance
12     .Set(x => x.FirstField, "Hello SO")
13     .Set(x => x.AnotherField, 42);
14 Console.WriteLine(myAnonInstance);
15 
16 public static class AnonymousObjectMutator
17 {
18     private const BindingFlags FieldFlags = BindingFlags.NonPublic | BindingFlags.Instance;
19     private static readonly string[] BackingFieldFormats = { "<{0}>i__Field", "<{0}>" };
20 
21     public static T Set<T, TProperty>(this T instance, Expression<Func<T, TProperty>> propExpression, TProperty newValue) where T : class
22     {
23         var pi = (propExpression.Body as MemberExpression).Member;
24         var backingFieldNames = BackingFieldFormats.Select(x => string.Format(x, pi.Name)).ToList();
25         var fi = typeof(T)
26             .GetFields(FieldFlags)
27             .FirstOrDefault(f => backingFieldNames.Contains(f.Name));
28         if (fi == null)
29         {
30             GetDynamicClassBydt("", "bb");
31             //throw new NotSupportedException(string.Format("Cannot find backing field for {0}", pi.Name));
32         }
33         else
34         {
35             fi.SetValue(instance, newValue);
36         }
37         return instance;
38     }
39 
40     /// <summary>
41     /// 使用dynamic根据DataTable的列名自动添加属性并赋值
42     /// </summary>
43     /// <param name="dt"></param>
44     /// <returns></returns> 
45     public static Object GetDynamicClassBydt(string file, string vl)
46     {
47         dynamic d = new System.Dynamic.ExpandoObject();
48         //创建属性，并赋值。
49         (d as System.Collections.Generic.ICollection<System.Collections.Generic.KeyValuePair<string, object>>).Add(new System.Collections.Generic.KeyValuePair<string, object>(file, vl));
50 
51         return d;
52     }
53 }
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posted @ 2022-02-08 16:33  EarlyTao  阅读(48)  评论(0)    收藏  举报