如果有人问你，如何调用一个类的private的方法或访问一个类的私有成员，如果你不知道反射的话，你会告诉他不可以。但是有了反射，这一切都成为可能。我有时候会想，既然使用private来限制访问，为什么又要用反射去破坏这种限制呢？也许可以通过侧面来解释这个问题，如果你要维护类的封装性，那请不要用反射，反射会破坏类的封装性。

    但反正某些情况下，又会变得相当地有用，比如你有一个dll，其中很多类被声明为internal，如果你要使用这些类，而又无法修改源代码的话，你就可以使用反射了，最近总结了一下，对反射做了一个封装。由于代码比较简单，没有做注释。

using System;
using System.Collections.Generic;
using System.Text;
using System.Reflection;

namespace UsefulUtility
{
    public class Invoker
    {
        private static BindingFlags flags = BindingFlags.Static | BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.IgnoreCase;

        public static Type GetType(Assembly asm, string typeFullName)
        {
            return asm.GetType(typeFullName);
        }

        public static Type GetInnerType(string hiddenTypeName, Type outerType)
        {
            Module typeModule = outerType.Module;
            return typeModule.GetType(hiddenTypeName);
        }

        public static MethodInfo GetMethod(Type type, string funcName, Type[] paramTypes)
        {
            if (paramTypes != null)
                return type.GetMethod(funcName, flags, null, paramTypes, null);
            else
                return type.GetMethod(funcName, flags);
        }

        public static MethodInfo GetMethod(Type type, string funcName)
        {
            return GetMethod(type, funcName, null);
        }

        public static object CallMethod(object obj, string funcName, params object[] parameters)
        {
            Type type = obj.GetType();
            MethodInfo method = GetMethod(type, funcName, GetTypesFromObjects(parameters));
            return method.Invoke(obj, parameters);
        }

        public static object CallStaticMethod(Type type, string funcName, params object[] parameters)
        {
            MethodInfo method = GetMethod(type, funcName, GetTypesFromObjects(parameters));
            return method.Invoke(null, parameters);
        }

        public static object GetProperty(object obj, string propertyName)
        {
            return GetProperty(obj, propertyName, null);
        }

        public static object GetProperty(object obj, string propertyName, params object[] index)
        {
            Type type = obj.GetType();
            return type.GetProperty(propertyName, flags).GetValue(obj, index);
        }

        public static object GetStaticProperty(Type type, string propertyName)
        {
            return GetStaticProperty(type, propertyName, null);
        }

        public static object GetStaticProperty(Type type, string propertyName, params object[] index)
        {
            return type.GetProperty(propertyName, flags).GetValue(null, index);
        }

        public static void SetProperty(object obj, string propertyName, object value)
        {
            SetProperty(obj, propertyName, value, null);
        }

        public static void SetProperty(object obj, string propertyName, object value, params object[] index)
        {
            Type type = obj.GetType();
            type.GetProperty(propertyName, flags).SetValue(obj, value, index);
        }

        public static void SetStaticProperty(Type type, string propertyName, object value)
        {
            SetStaticProperty(type, propertyName, value, null);
        }

        public static void SetStaticProperty(Type type, string propertyName, object value, params object[] index)
        {
            type.GetProperty(propertyName, flags).SetValue(null, value, index);
        }

        public static object GetField(object obj, string fieldName)
        {
            Type type = obj.GetType();
            return type.GetField(fieldName, flags).GetValue(obj);
        }

        public static object GetSaticField(Type type, string fieldName)
        {
            return type.GetField(fieldName, flags).GetValue(null);
        }

        public static void SetField(object obj, string fieldName, object value)
        {
            Type type = obj.GetType();
            type.GetField(fieldName, flags).SetValue(obj, value);
        }

        public static void SetStaticField(Type type, string fieldName, object value)
        {
            type.GetField(fieldName, flags).SetValue(null, value);
        }

        private static ConstructorInfo GetConstructor(Type type, Type[] paramTypes)
        {
            return type.GetConstructor(paramTypes);
        }

        public static object CreateInstance(Type type, Type[] paramTypes, params object[] parameters)
        {
            return GetConstructor(type, paramTypes).Invoke(parameters);
        }

        public static object CreateInstance(Type type, params object[] parameters)
        {
            return GetConstructor(type, GetTypesFromObjects(parameters)).Invoke(parameters);
        }

        private static Type[] GetTypesFromObjects(object[] objs)
        {
            Type[] types = new Type[objs.Length];
            for (int i = 0; i < types.Length; i++)
                types[i] = objs[i].GetType();
            return types;
        }

        public static void AddEventHandler(object obj, string eventName, MethodInfo method, object methodOwner)
        {
            EventInfo eventInfo = obj.GetType().GetEvent(eventName, flags);
            Delegate eventDeleg = Delegate.CreateDelegate(eventInfo.EventHandlerType, methodOwner, method);
            eventInfo.AddEventHandler(obj, eventDeleg);
        }

        public static void RemoveEventHandler(object obj, string eventName, MethodInfo method,object methodOwner)
        {
            EventInfo eventInfo = obj.GetType().GetEvent(eventName, flags);
            Delegate eventDeleg = Delegate.CreateDelegate(eventInfo.EventHandlerType, methodOwner, method);
            eventInfo.RemoveEventHandler(obj, eventDeleg);
        }
    }
}

    下面的代码对上面的一些方法进行测试，由于手头只有一个Fetion SDK.dll的文件，所以就拿他开刀了，实现简单的登录，登录后发送一条测试信息到我的手机，为了安全略去了某些信息。

using System;
using System.Collections.Generic;
using System.Text;
using UsefulUtility;
using System.Reflection;

namespace ConsoleApplication1
{
    class Program
    {
        static object sdk;
        static Assembly asm;
        [STAThread]
        static void Main(string[] args)
        {
            // 载入程序集
            asm = Assembly.LoadFrom("Fetion SDK.dll");
            // 获取Fetion SDK的类型
            Type type = Invoker.GetType(asm, "com.hetaoos.FetionSDK.FetionSDK");
            // 实例化sdk
            sdk = Invoker.CreateInstance(type);
            // 获取账号管理的属性
            object accountManager = Invoker.GetProperty(sdk, "AccountManager");
            // 设置用户名和密码
            Invoker.CallMethod(accountManager, "FillUserIdAndPassword", new object[] { "手机号码", "飞信密码", false });
            // 监听事件
            Invoker.AddEventHandler(sdk, "SDK_UserSatusChange", Invoker.GetMethod(typeof(Program), "sdk_SDK_UserSatusChange"), null);
            // 调用登录方法
            Invoker.CallMethod(accountManager, "Login");
        }
        static void Hello()
        {
            Console.WriteLine("hello in Hello");
        }

        static void sdk_SDK_UserSatusChange(object sender, EventArgs e)
        {

            Console.WriteLine(Invoker.GetProperty(e, "NewStatus"));
            Console.WriteLine(Invoker.GetSaticField(Invoker.GetType(asm, "Imps.Client.UserAccountStatus"), "Logon"));
            // 这里用==不好使，要用Equals，不知道为什么
            if (Invoker.GetProperty(e, "NewStatus").Equals(Invoker.GetSaticField(Invoker.GetType(asm, "Imps.Client.UserAccountStatus"), "Logon")))
            {
                Console.WriteLine("hello");
                object contactControl = Invoker.GetProperty(sdk, "ContactControl");
                object sendSMS = Invoker.GetProperty(contactControl, "SendSMS");
                Invoker.CallMethod(sendSMS, "SendSMS", "要发送信息的飞信号或手机号码", "hello, a test");
            }
        }
    }
}