通过反射访问对象私有和保护成员

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using NUnit.Framework;
using System.Reflection;
namespace Com.xxx.Utils
{
    /// <summary>
    /// 单元测试工具类
    /// </summary>
    public static class UnitTestHelper
    {
        public static void AssertException<TCallBack>
            (string errorMessage,
            TCallBack callBackMethod,
            params object[] parameters)
        {
            object method = callBackMethod as object;
            bool hasException = false;
            try
            {
                ((Delegate)method).DynamicInvoke(parameters);
            }
            catch (Exception e)
            {
                hasException = true;
                Assert.AreEqual(errorMessage, e.InnerException.Message);
            }
            if (!hasException)
            {
                throw new Exception(errorMessage + "异常没有出现！");
            }
        }
        public static void SetNonPublicField(object obj, string fieldName, object newValue)
        {
            try
            {
                FieldInfo field = obj.GetType().GetField(fieldName, 
                    BindingFlags.NonPublic | BindingFlags.Instance);
                field.SetValue(obj, newValue);
            }
            catch (Exception e)
            {
                  throw e.InnerException;
            }
        }
        public static object GetNonPublicField(object obj, string fieldName)
        {
            try
            {
                FieldInfo field = obj.GetType().GetField(fieldName, 
                    BindingFlags.NonPublic | BindingFlags.Instance);
                return field.GetValue(obj);
            }
            catch (Exception e)
            {
                 throw e.InnerException;
            }
        }
        public static void SetNonPublicProperty(object obj, string propertyName, object newValue)
        {
            try
            {
                PropertyInfo property = obj.GetType().GetProperty(propertyName, 
                    BindingFlags.NonPublic | BindingFlags.Instance);
                property.SetValue(obj, newValue, null);
            }
            catch (Exception e)
            {
                throw e.InnerException;
            }
        }
        public static object GetNonPublicProperty(object obj, string propertyName)
        {
            try
            {
                PropertyInfo property = obj.GetType().GetProperty(propertyName,
                    BindingFlags.NonPublic | BindingFlags.Instance);
                return property.GetValue(obj, null);
            }
            catch (Exception e)
            {
                throw e.InnerException;
            }
        }
        public static object CallNonPublicMethod(object obj, string methodName, params object[] args)
        {
            try
            {
                MethodInfo method = obj.GetType().GetMethod(methodName, 
                    BindingFlags.NonPublic | BindingFlags.Instance);
                return method.Invoke(obj, args);
            }
            catch (Exception e)
            {
                throw e.InnerException;
            }
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using NUnit.Framework;
using Com.xxx.Utils;
namespace Com.xxx.xxx.Test.Utils
{
    public class A
    {
        private int pri;

        protected string pro;

        protected string Pro { get; set; }

        private string PriMethod(string hello)
        {
            return hello + " xhan Pri";
        }
        protected string ProMethod(string hello)
        {
            return hello + " xhan Pro";
        }

    }
    [TestFixture]
    public class UnitTestHelperTest
    {
        [Test]
        public void TestSetGetNonPoublicField()
        {
            A a = new A();
            UnitTestHelper.SetNonPublicField(a, "pri", 1);

            int pri = (int)UnitTestHelper.GetNonPublicField(a, "pri");
            Assert.AreEqual(1, pri);

            UnitTestHelper.SetNonPublicField(a, "pro", "hello");
            Assert.AreEqual("hello", UnitTestHelper.GetNonPublicField(a, "pro").ToString());
        }
        [Test]
        public void TestGetSetNonPublicProperty()
        {
            A a = new A();
            UnitTestHelper.SetNonPublicProperty(a, "Pro", "xhan");
            Assert.AreEqual("xhan", UnitTestHelper.GetNonPublicProperty(a, "Pro"));
        }
        [Test]
        public void TestCallNonPublicMethod()
        {
            A a = new A();
            string priResult = UnitTestHelper.CallNonPublicMethod(a, "PriMethod", "ni hao").ToString();

            Assert.AreEqual("ni hao xhan Pri", priResult);

            string proResult = UnitTestHelper.CallNonPublicMethod(a, "ProMethod", "ni hao").ToString();

            Assert.AreEqual("ni hao xhan Pro", proResult);
        }
    }
}