C# 通过反射实例化BLL业务逻辑层

BLLFactory的对象统一调用规则

在我的框架里面，所有的业务类调用都是以BLLFactory入口进行开始创建，传递业务对象进去即可创建，这种统一入口的方式能够方便记忆，并减少代码，更重要的是能够很好把一些如缓存规则、创建规则封装起来，简化代码。BLLFactory的创建示意图如下所示。

方法一：

using Globalegrow.Toolkit;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Text;

namespace Globalegrow.BLL
{
    /// <summary>
    /// 对业务类进行构造的工厂类
    /// </summary>
    /// <typeparam name="T">业务对象类型</typeparam>
    public class BLLFactory<T> where T : class
    {
        private static Hashtable objCache = new Hashtable();
        private static object syncRoot = new Object();

        /// <summary>
        /// 创建或者从缓存中获取对应业务类的实例
        /// </summary>
        public static T Instance
        {
            get
            {
                string CacheKey = typeof(T).FullName;
                T bll = (T)objCache[CacheKey];　
                if (bll == null)
                {
                    lock (syncRoot)
                    {
                        if (bll == null)
                        {
                            Assembly assObj = Assembly.Load(typeof(T).Assembly.GetName().Name);
                            object obj = assObj.CreateInstance(CacheKey);
                            bll = obj as T;
                            objCache.Add(typeof(T).FullName, bll);
                        }
                    }
                }
                return bll;
            }
        }
    }
}

方法二：

using Globalegrow.Toolkit;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Text;

namespace Globalegrow.BLL
{
    /// <summary>
    /// 对业务类进行构造的工厂类
    /// </summary>
    /// <typeparam name="T">业务对象类型</typeparam>
    public class BLLFactory<T> where T : class
    {
        private static object syncRoot = new Object();

        /// <summary>
        ///
        /// </summary>
        public static T Instance
        {
            get
            {
                string CacheKey = typeof(T).FullName;
                lock (syncRoot)
                {
                    T bll = Reflect<T>.Create(typeof(T).FullName, typeof(T).Assembly.GetName().Name);
                    return bll;
                }
            }
        }
    }
}

反射需要用到的扩展方法

using System.Collections;
using System.Reflection;

namespace Globalegrow.Toolkit
{
    public class Reflect<T> where T : class
    {
        private static Hashtable m_objCache = null;

        public static Hashtable ObjCache
        {
            get
            {
                if (m_objCache == null)
                {
                    m_objCache = new Hashtable();
                }
                return m_objCache;
            }
        }

        public static T Create(string sName, string sFilePath)
        {
            return Create(sName, sFilePath, true);
        }

        public static T Create(string sName, string sFilePath, bool bCache)
        {
            string CacheKey = sFilePath + "." + sName;
            T objType = null;
            if (bCache)
            {
                objType = (T)ObjCache[CacheKey];    //从缓存读取
                if (!ObjCache.ContainsKey(CacheKey))
                {
                    Assembly assObj = CreateAssembly(sFilePath);
                    object obj = assObj.CreateInstance(typeof(T).FullName);
                    objType = (T)obj;

                    ObjCache.Add(CacheKey, objType);// 写入缓存 将DAL内某个对象装入缓存
                }
            }
            else
            {
                objType = (T)CreateAssembly(sFilePath).CreateInstance(CacheKey); //反射创建
            }

            return objType;
        }

        public static Assembly CreateAssembly(string sFilePath)
        {
            Assembly assObj = (Assembly)ObjCache[sFilePath];
            if (assObj == null)
            {
                assObj = Assembly.Load(sFilePath);
                if (!ObjCache.ContainsKey(sFilePath))
                {
                    ObjCache.Add(sFilePath, assObj);//将整个ITDB。DAL。DLL装入缓存
                }
            }
            return assObj;
        }
    }
}

调用:

var systemConfigBLL = BLLFactory<SystemConfigBLL>.Instance.GetDBServiceTime();