MSBuild + MSILInect实现编译时AOP之预览

2025-02-18 技术教程

在本文之前的前几篇浅谈.NET编译时注入（C#-->IL）、浅谈VS编译自定义编译任务—MSBuild Task(csproject)、编译时MSIL注入--实践Mono Cecil(1)已经讨论了MSBuild和Mono.Cicel。在这里我们将会利用它来实现一个简单的编译时AOP注入机制（这里所说的编译时是指c#到MSIL的预编译过程）。我更倾向于像EL（微软企业库框架）这类动态AOP。编译时AOP有PostSharp这种被称之为静态AOP框架，其优势在于直接代码语句，性能更好，它不需要我们多余的代码，像EL这种动态AOP，一般我们是不能直接new一个对象，需要容器（Container），在一些你的框架应用种，有时就需要使用者了解，再入我们对于WinForm、WebForm等.net平台上主流的基于微软事件机制的框架，事件方法的截获，往往我们需要改变、包装。在这时静态AOP就显出了他的优势。

Class Diagram：

1：IMethodInject：Interface，拥有Executeing，Exceptioned，ExecuteSuccess三个契约为别为执行前，异常，成功。它们都有公同的参数类型：MethodExecutionEventArgs

Executeing：返回值为bool类型，将决定是否继续执行方法体。Exceptioned：属性Eeption代表发生的异常信息，返回值ExceptionStrategy（取值：Handle, ReThrow, ThrowNew）决定异常处理机制，Handle已处理并忽略，ReThrow重新抛出，ThrowNew抛出一个包装后的来源于MethodExecutionEventArgs 的Exception。ExecuteSuccess，对于拥有返回值的方法，可以修改MethodExecutionEventArgs 的ReturnValue，修改返回值。最后MethodExecutionEventArgs的Order决定多个Attribute的注入先后，即方法截获的先后顺序。

1：MethodInterceptBase：针对于方法Attribute标签，实现方法截获View Code

[AttributeUsage(AttributeTargets.Method,Inherited=false,AllowMultiple=false)] publicclassMethodInterceptBase:Attribute,IMethodInject { publicintOrder{ get; set; } #regionIMethodInjectMembers publicvirtualboolExecuteing(MethodExecutionEventArgsargs) { returntrue; } publicvirtualExceptionStrategyExceptioned(MethodExecutionEventArgsargs) { returnExceptionStrategy.ReThrow; } publicvirtualvoidExecuteSuccess(MethodExecutionEventArgsargs) { } #endregion } 复制代码

2：MatchedMethodInterceptBase：和上面方法之上的MethodInterceptBase大体一致，区别在于其应用于class之上，属性Rule为截获方法匹配（应用于多个方法之上相同截获），支持*匹配。

ViewCode [AttributeUsage(AttributeTargets.Class,Inherited=false,AllowMultiple=false)] publicclassMatchedMethodInterceptBase:Attribute,IMethodInject { publicintOrder{ get; set; } publicstringRule{ get; set; } #regionIMethodInjectMembers publicvirtualboolExecuteing(MethodExecutionEventArgsargs) { returntrue; } publicvirtualExceptionStrategyExceptioned(MethodExecutionEventArgsargs) { returnExceptionStrategy.ReThrow; } publicvirtualvoidExecuteSuccess(MethodExecutionEventArgsargs) { } #endregion } 复制代码

3：PropertyInterceptBase：实现属性的注入，其属性Action（enum PropertyInterceptAction：None Get, Set）指注入属性的get或者Set；View Code

其上默认都是Executeing继续执行，Exceptioned为抛出不处理，成功不修改result。

下面是一个简单测试Code：

ViewCode usingSystem; usingSystem.Collections.Generic; usingSystem.Linq; usingSystem.Text; usingSystem.Reflection; usingGreen.AOP; namespaceTest { //[TestAOP2Attribute(Rule="TestMethod1*")] publicclassClass1 { //[TestAOPPropertyAttribute(Action=PropertyInterceptAction.Set)] [TestAOPPropertyGetAttribute(Action=PropertyInterceptAction.Get)] publictestStrustTestProperty { get; set; } [Obsolete()] publicstaticvoidMain(string[]args) { try { vary=newClass1(); //y.TestProperty=DateTime.Now; Console.WriteLine(y.TestProperty); } catch(Exceptionex) { Console.WriteLine(ex.ToString()); } //newClass1().TestMethod1(1,2,null); Console.Read(); //thrownewException("exfffffffffffffffffffff"); } //[TestAOPAttribute(Order=1)] //[TestAOP1Attribute(TestProperty=1,Template="sdsdsd",Order=0)] publicClass1TestMethod1(inti,intj,Class1c) { Console.WriteLine("ok"); returnnewClass1(); } } publicclassTestAOPPropertyGetAttribute:Green.AOP.PropertyInterceptBase { #regionIMethodInjectMembers publicoverrideboolExecuteing(Green.AOP.MethodExecutionEventArgsargs) { Console.WriteLine("------------------"+args); Console.WriteLine(args.Instance); Console.WriteLine(args.Method); Console.WriteLine(this.GetType()+":"+"Executeing"); returntrue; } publicoverrideGreen.AOP.ExceptionStrategyExceptioned(Green.AOP.MethodExecutionEventArgsargs) { Console.WriteLine(this.GetType()+":"+"Exceptioned"); returnGreen.AOP.ExceptionStrategy.ReThrow; } publicoverridevoidExecuteSuccess(Green.AOP.MethodExecutionEventArgsargs) { Console.WriteLine("-----------"); Console.WriteLine(this.GetType()+":"+"ExecuteSuccess"+"--result:"+args.ReturnValue); } #endregion } publicclassTestAOPPropertyAttribute:Green.AOP.PropertyInterceptBase { #regionIMethodInjectMembers publicoverrideboolExecuteing(Green.AOP.MethodExecutionEventArgsargs) { Console.WriteLine(args.Instance); Console.WriteLine(args.Method); Console.WriteLine(this.GetType()+":"+"Executeing"); returntrue; } publicoverrideGreen.AOP.ExceptionStrategyExceptioned(Green.AOP.MethodExecutionEventArgsargs) { Console.WriteLine(this.GetType()+":"+"Exceptioned"); returnGreen.AOP.ExceptionStrategy.Handle; } publicoverridevoidExecuteSuccess(Green.AOP.MethodExecutionEventArgsargs) { Console.WriteLine(this.GetType()+":"+"ExecuteSuccess"); } #endregion } publicclassTestAOP2Attribute:Green.AOP.MatchedMethodInterceptBase { #regionIMethodInjectMembers publicoverrideboolExecuteing(Green.AOP.MethodExecutionEventArgsargs) { Console.WriteLine(args.Instance); Console.WriteLine(args.Method); Console.WriteLine(this.GetType()+":"+"Executeing"); returntrue; } publicoverrideGreen.AOP.ExceptionStrategyExceptioned(Green.AOP.MethodExecutionEventArgsargs) { Console.WriteLine(this.GetType()+":"+"Exceptioned"); returnGreen.AOP.ExceptionStrategy.Handle; } publicoverridevoidExecuteSuccess(Green.AOP.MethodExecutionEventArgsargs) { Console.WriteLine(this.GetType()+":"+"ExecuteSuccess"); } #endregion #regionIMethodInjectMembers publicboolMatch(System.Reflection.MethodBasemethod) { returntrue; } #endregion } //[AttributeUsage(AttributeTargets.Method)] publicclassTestAOPAttribute:Green.AOP.MethodInterceptBase { #regionIMethodInjectMembers publicoverrideboolExecuteing(Green.AOP.MethodExecutionEventArgsargs) { Console.WriteLine(this.GetType()+":"+"Executeing"); returntrue; } publicoverrideGreen.AOP.ExceptionStrategyExceptioned(Green.AOP.MethodExecutionEventArgsargs) { Console.WriteLine(this.GetType()+":"+"Exceptioned"); returnGreen.AOP.ExceptionStrategy.Handle; } publicoverridevoidExecuteSuccess(Green.AOP.MethodExecutionEventArgsargs) { Console.WriteLine(this.GetType()+":"+"ExecuteSuccess"); } #endregion #regionIMethodInjectMembers publicboolMatch(System.Reflection.MethodBasemethod) { returntrue; } #endregion } [AttributeUsage(AttributeTargets.Method)] publicclassTestAOP1Attribute:Attribute,Green.AOP.IMethodInject { publicintOrder{ get; set; } publicintTestProperty { get; set; } publicstringTemplate { get; set; } #regionIMethodInjectMembers publicboolExecuteing(Green.AOP.MethodExecutionEventArgsargs) { Console.WriteLine(this.GetType()+":"+"Executeing"); returntrue; } publicGreen.AOP.ExceptionStrategyExceptioned(Green.AOP.MethodExecutionEventArgsargs) { Console.WriteLine(this.GetType()+":"+"Exceptioned"); returnGreen.AOP.ExceptionStrategy.Handle; } publicvoidExecuteSuccess(Green.AOP.MethodExecutionEventArgsargs) { Console.WriteLine(this.GetType()+":"+"ExecuteSuccess"); } #endregion #regionIMethodInjectMembers publicboolMatch(System.Reflection.MethodBasemethod) { returntrue; } #endregion } } 复制代码

注意测试有两种方式（由于没有安装包）：

1：先重编译测试项目，运行ConsoleApplication2（在属性中修改控制台其实参数）。在查看测试项目。

2：将项目ConsoleApplication2修改为类库，在添加修改csprojec信息，Task位于Green.AOP.MyBuildTask，具体可以参见上一篇浅谈VS编译自定义编译任务—MSBuild Task(csproject)。

在后续将会从简单Demo分析实现原理。

[AttributeUsage(AttributeTargets.Property,Inherited=false,AllowMultiple=false)] publicclassPropertyInterceptBase:Attribute,IMethodInject { publicPropertyInterceptActionAction{ get; set; } publicintOrder{ get; set; } #regionIMethodInjectMembers publicvirtualboolExecuteing(MethodExecutionEventArgsargs) { returntrue; } publicvirtualExceptionStrategyExceptioned(MethodExecutionEventArgsargs) { returnExceptionStrategy.ReThrow; } publicvirtualvoidExecuteSuccess(MethodExecutionEventArgsargs) { } #endregion } 复制代码