AOP面向切面编程(aspect OrientedPRogramming)，是通过预编译方式和运行期动态代理实现程序功能的统一维护的一种技术。Spring框架用的核心技术就是AOP，是函数式编程的一种衍生范型。利用AOP的好处就是可以对业务逻辑进行隔离，降低耦合度，提高程序的可重用性，同时提高了开发的效率。开源的AOP也有不少,我这里用的KingAOP.
1 项目结构[flash=500,400]http://s1.knowsky.com/20160211/lhvhtqu3na009.jpg[/flash]
2 定义一个日志记录的实体类User和LoggingAspect切面日志类1namespaceAOPDemo.Logging2{3classUser4{5publicintID {get;set; }6publicstringName {get;set; }7publicstringPwd{get;set;}8publicstringip{get;set; }9publicstringState {get;set; }10publicSystem.DateTime LoginTime {get;set; }1112}13}
1usingSystem;2usingSystem.Text;3usingKingAOP.Aspects;45namespaceAOPDemo.Logging6{7internalclassLoggingAspect : OnMethodBoundaryAspect8{9publicoverridevoidOnEntry(MethodExecutionArgs args)10{11stringlogData = CreateLogData("Entering", args);12Console.WriteLine(logData);13}1415publicoverridevoidOnExit(MethodExecutionArgs args)16{17stringlogData = CreateLogData("Leaving", args);18Console.WriteLine(logData);19}20///<summary>21///AOP对于登录日志逻辑,只需在此进行修改即可,无需修改被切面的处理类22///</summary>23///<param name="methodStage"></param>24///<param name="args"></param>25///<returns></returns>26privatestringCreateLogData(stringmethodStage, MethodExecutionArgs args)27{28varstr =newStringBuilder();29str.AppendLine();30str.AppendLine(string.Format(methodStage +"{0}", args.Method));31foreach(varargumentinargs.Arguments)32{33varargType =argument.GetType();3435str.Append(argType.Name +":");3637if(argType ==typeof(string) ||argType.IsPrimitive)38{39str.Append(argument);40}41else42{43foreach(varpropertyinargType.GetProperties())44{45str.AppendFormat("{0} = {1};",46property.Name, property.GetValue(argument,null));47}48}49}50returnstr.ToString();51}52}53}
3 Login类该类必须实现IDynamicMetaObjectProvider的GetMetaObject方法,同时在需要切面的方法上用属性[LoggingAspect]进行标注,LoggingAspect属性也就是我们上面定义的LoggingAspect切片处理类.
1usingSystem.Dynamic;2usingSystem.Linq.Expressions;3usingKingAOP;4namespaceAOPDemo.Logging5{6///<summary>7///登录逻辑处理,只需添加一个LoggingAspect即可实现日志功能,达到逻辑和通用处理的逻辑分离8///</summary>9internalclassLogin : IDynamicMetaObjectProvider10{11//添加登录切面12[LoggingAspect]13publicvoidLoginValdate(User entity)14{15//只需进行业务逻辑处理,无需进行日志处理16if(entity.Name =="jack"&& entity.Pwd =="wang")17{18entity.State ="Logged";19}20else21{22entity.State ="Error";23}242526}27///<summary>28///IDynamicMetaObjectProvider的实现29///</summary>30///<param name="parameter"></param>31///<returns></returns>32publicDynamicMetaObject GetMetaObject(Expression parameter)33{34//need for AOP weaving35returnnewAspectWeaver(parameter,this);36}37}38}
[flash=500,400]http://s1.knowsky.com/20160211/lfj22l0fgnm09.jpg[/flash]
调试代码如下:
1//测试感觉KingAOP必须有一个dynamic才能切面2Logging.Login test =newLogging.Login();3dynamicentity =newLogging.User { Name ="Jon", ID =99,Pwd="wang",State="",LoginTime=System.DateTime.Now};4test.LoginValdate(entity);