概述

之前做微信项目的时候，会涉及到一个回调，大家都知道回调事件是很多类型的，一般是根据不同的类型在进行不同的逻辑处理。

这样就会延伸出一个问题，就是入口处会有一大堆if判断。这样本身是没什么问题的，只是看起来比较别扭，那么怎么把if干掉了 。这时候工厂模式派上用场了。下面我们来看下具体如何实现。

代码实现

1、定义虚方法Notify

  #region 定义虚方法public class Notify{public virtual Dingdong.Wallet.Common.Result NotifyHandle(NotifyResult Result, dynamic respData){Dingdong.Wallet.Common.Result r = new Result();return r;}}#endregion

2、定义Attribute属性，并且指定一个参数ServiceName

  [System.Serializable][System.AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, AllowMultiple = true, Inherited = false)][System.Runtime.InteropServices.ComVisible(true)]public class InterfaceAttribute : Attribute{private string _ServiceName;        public InterfaceAttribute(){}public string ServiceName{get { return _ServiceName; }set { _ServiceName = value; }}}

3、实现一个工厂NotifyFactory，通过反射把包含Attribute的找出来

  #region Factorypublic class NotifyFactory{public Notify CreateNotify(string _name){Dictionary<string, string> dic = new Dictionary<string, string>();string strNamespace = Assembly.GetExecutingAssembly().GetName().Name;//    LogHelper.WriteInfo("命名空间：" + strNamespace);var classes = Assembly.Load(strNamespace).GetTypes();foreach (var item in classes){Object[] obs = item.GetCustomAttributes(typeof(InterfaceAttribute), false);foreach (InterfaceAttribute record in obs){dic.Add(record.ServiceName, item.Name);//     LogHelper.WriteInfo("接口名称：" + record.ServiceName + "-类名：" + item.Name);}}Assembly myAssembly = Assembly.GetExecutingAssembly();Notify Notify = (Notify)myAssembly.CreateInstance(strNamespace + "." + dic[_name]);return Notify;}}#endregion

4、前端通过传入ServiceName，实现不同的业务逻辑

      NotifyFactory Factory = new NotifyFactory();Notify Fa = Factory.CreateNotify(Notifyresult.ServiceName);//PERSONAL_REGISTER_EXPANDDingdong.Wallet.Common.Result r= Fa.NotifyHandle(Notifyresult, Result);//new  NotifyResult() ,"respData"LogHelper.WriteInfo("异步通知结束");LogHelper.WriteInfo("异步通知结束r:"+ r.Serialize());

5、其中一个具体的方法重载NotifyHandle，并且定义   [Interface(ServiceName = "DIRECT_RECHARGE")]

  [Export]/// <summary>/// 代扣交易   InterfaceAttribute 接口名称  类名自定义 确保命名空间在FuYin.Wallet.Notify 下/// </summary>[Interface(ServiceName = "DIRECT_RECHARGE")]public class DirectRecharge : Notify{public override Result NotifyHandle(NotifyResult r, dynamic respData){//  return base.NotifyHandle(Result, respData);//r.ServiceName 异步通知接口方法//  r.ResponseType  //回调类型LogHelper.WriteInfo("公共数据:" + r.Serialize());DirectRechargeNotifyResult model = JsonConvert.DeserializeObject<DirectRechargeNotifyResult>(respData);LogHelper.WriteInfo("业务处理数据:" + model.Serialize());using (var context = new MefContext()){var svc = context.GetService<IDeTransactionService>();return svc.DirectRechargeNotify(model);}}}

这样就可以把一大堆if去掉了，代码看起来也简洁多了。