參考鏈接：

https://www.cnblogs.com/adodo1/p/4328198.html

代碼如下：

 1 using System;
 2 using System.Reflection;
 3 using UnityEngine;
 4 
 5 public static class ObjectExtension
 6 {
 7     //獲取私有字段的值
 8     public static T GetPrivateField<T>(this object instance, string fieldName)
 9     {
10         BindingFlags flags = BindingFlags.Instance | BindingFlags.NonPublic;
 
11         Type type = instance.GetType();
12         FieldInfo info = type.GetField(fieldName, flags);
13         return (T)info.GetValue(instance);
14     }
15 
16     //設置私有字段的值
17     public static void SetPrivateField(this object instance, string fieldName, object value)
18     {
19         BindingFlags flags = BindingFlags.Instance | BindingFlags.NonPublic;
 
20         Type type = instance.GetType();
21         FieldInfo info = type.GetField(fieldName, flags);
22         info.SetValue(instance, value);
23     }
24 
25     //獲取私有屬性的值
26     public static T GetPrivateProperty<T>(this object instance, string propertyName)
27     {
28         BindingFlags flags = BindingFlags.Instance | BindingFlags.NonPublic;
 
29         Type type = instance.GetType();
30         PropertyInfo info = type.GetProperty(propertyName, flags);
31         return (T)info.GetValue(instance, null);
32     }
33 
34     //設置私有屬性的值
35     public static void SetPrivateProperty<T>(this object instance, string propertyName, object value)
36     {
37         BindingFlags flags = BindingFlags.Instance | BindingFlags.NonPublic;
38         Type type = instance.GetType();
39         PropertyInfo info = type.GetProperty(propertyName, flags);
40         info.SetValue(instance, value, null);
41     }
42 
43     //調用私有方法
44     public static object CallPrivateMethod(this object instance, string methodName, params object[] param)
45     {
46         BindingFlags flags = BindingFlags.Instance | BindingFlags.NonPublic;
47         Type type = instance.GetType();
48         MethodInfo info = type.GetMethod(methodName, flags);
49         return info.Invoke(instance, param);
50     }
51 }
52 
53 public class TestReflectionClass {
54     private int field;
55     private string Property { get; set; }
56 
57     public TestReflectionClass()
58     {
59         field = 1;
60         Property = "a";
61     }
62 
63     private void SetValue(int field, string property)
64     {
65         this.field = field;
66         this.Property = property;
67     }
68 }
69 
70 public class TestReflection : MonoBehaviour {
71 
72     void Start ()
73     {
74         TestReflectionClass testClass = new TestReflectionClass();
75 
76         print(testClass.GetPrivateField<int>("field"));//1
77         print(testClass.GetPrivateProperty<string>("Property"));//a
78 
79         testClass.CallPrivateMethod("SetValue", 2, "b");
80 
81         testClass.SetPrivateProperty<string>("Property", "c");
82         print(testClass.GetPrivateField<int>("field"));//2
83         print(testClass.GetPrivateProperty<string>("Property"));//c
84     }
85 }

[C#]通過反射訪問類私有成員