C # emit implements a proxy for a class

usingSystem;usingSystem.Linq;usingSystem.Reflection;usingSystem.Reflection.Emit;namespaceemitcreatedynamicproxy{classProgram {Static voidMain (string[] args) {            varCommand = proxy.of<command>(); Command.            Execute ();        Console.ReadLine (); }    }     Public classCommand { Public Virtual voidExecute () {Console.WriteLine ("Hello kitty!"); }    }      Public classInterceptor { Public ObjectInvoke (Object@object,string@method,Object[] Parameters) {Console.WriteLine (string. Format ("before invoke [{0}] ...", @method)); varRetobj =@object. GetType (). GetMethod (@method).            Invoke (@object, parameters); Console.WriteLine (string. Format ("After invoke [{0}] ...", @method)); returnRetobj; }    }     Public classProxy { Public StaticT of<t>()         {            stringnameofassembly =typeof(T). Name +"proxyassembly"; stringNameofmodule =typeof(T). Name +"Proxymodule"; stringNameoftype =typeof(T). Name +"Proxy"; varAssemblyName =NewAssemblyName (nameofassembly); varAssembly =Appdomain.currentdomain.            DefineDynamicAssembly (AssemblyName, Assemblybuilderaccess.run); varModuleBuilder =Assembly.                      DefineDynamicModule (Nameofmodule); varTypeBuilder =Modulebuilder.definetype (Nameoftype, Typeattributes.public,typeof(T)); Injectinterceptor<T>(TypeBuilder); vart =TypeBuilder.CreateType (); return(t) activator.createinstance (t); }        Private Static voidInjectinterceptor<t>(TypeBuilder TypeBuilder) {//----define fields----            varFieldinterceptor =Typebuilder.definefield ("_interceptor",typeof(Interceptor), fieldattributes.private); //----define costructors----            varConstructorBuilder =Typebuilder.defineconstructor (Methodattributes.public, Callingconventions.standard,NULL); varIlofctor =Constructorbuilder.getilgenerator ();            Ilofctor.emit (OPCODES.LDARG_0); Ilofctor.emit (Opcodes.newobj,typeof(Interceptor). GetConstructor (Newtype[0]));            Ilofctor.emit (OPCODES.STFLD, fieldinterceptor);            Ilofctor.emit (Opcodes.ret); //----Define methods----            varMethodsoftype =typeof(T). GetMethods (BindingFlags.Public |bindingflags.instance);  for(vari =0; i < methodsoftype.length; i++)            {                varMETHOD =Methodsoftype[i]; varMethodparametertypes =method. GetParameters (). Select (P=p.parametertype).                ToArray (); varMethodBuilder =Typebuilder.definemethod (method. Name, Methodattributes.public|methodattributes.virtual, Callingconventions.standard, method.                ReturnType, methodparametertypes); varIlofmethod =Methodbuilder.getilgenerator ();                Ilofmethod.emit (OPCODES.LDARG_0);                Ilofmethod.emit (OPCODES.LDFLD, fieldinterceptor); //Create instance of TIlofmethod.emit (Opcodes.newobj,typeof(T). GetConstructor (Newtype[0])); Ilofmethod.emit (Opcodes.ldstr, method.                Name); //build the method parameters                if(Methodparametertypes = =NULL) {ilofmethod.emit (opcodes.ldnull); }                Else                {                    varParameters = Ilofmethod.declarelocal (typeof(Object[]));                    Ilofmethod.emit (OPCODES.LDC_I4, methodparametertypes.length); Ilofmethod.emit (Opcodes.newarr,typeof(Object));                    Ilofmethod.emit (opcodes.stloc, parameters);  for(varj =0; J < Methodparametertypes.length; J + +) {ilofmethod.emit (opcodes.ldloc, parameters);                        Ilofmethod.emit (OPCODES.LDC_I4, J); Ilofmethod.emit (Opcodes.ldarg, J+1);                    Ilofmethod.emit (OPCODES.STELEM_REF);                } ilofmethod.emit (Opcodes.ldloc, parameters); }                //Call Invoke () Method of InterceptorIlofmethod.emit (Opcodes.callvirt,typeof(Interceptor). GetMethod ("Invoke")); //Pop the stack if return void                if(method. ReturnType = =typeof(void) {ilofmethod.emit (opcodes.pop); }                // CompleteIlofmethod.emit (Opcodes.ret); }        }    }}

C # emit implements a proxy for a class