之前實作了NetCore實作自定義IOC容器注入，在Controller使用事物的程序中思考是否能夠像Spring一樣通過自定義注解實作事物管理，思路圖如下
事物的動作拆分只需要根據當前執行執行緒劃分Connection物件并開啟事物即可，重點是在Emit代碼織入程序中對例外捕捉的處理
處理程序中主要會用到BeginExceptionBlock開啟try代碼塊，BeginCatchBlock開啟catch代碼塊，EndExceptionBlock結束例外捕捉代碼塊
創建事物注解Transitional用來標記Controller中需要事物執行的方法
[AttributeUsage(AttributeTargets.Method)] public class Transitional : System.Attribute { public bool AutoRollBack { set; get; } public Transitional() { AutoRollBack = true; } }
Emit編織時需要注意例外捕捉時有回傳值時建立全域變數回傳，執行事物管理器類的靜態方法直接使用call，例如 ilOfMethod.Emit(OpCodes.Call, typeof(TransitionManage).GetMethod("DoRollBack"))，同時Controller被攔截的方法需要標記Transitional注解且同時是虛方法
被代理類示例
public class TransitionalMovie { [Transitional] public virtual void Test1() { Console.WriteLine("Test1"); } [Transitional] public virtual string Test2() { Console.WriteLine("Test2"); throw new Exception("111"); return "Hello"; } [Transitional(AutoRollBack = false)] public virtual void Test3(string Key) { Console.WriteLine("Test3"); Console.WriteLine(Key); }
IOC使用示例，IOC容器原理可參考c#通過Emit方式實作動態代理
var container = new ContainerBuilder(); container.RegisterType<TransitionalMovie>().EnableIntercept(); container.Build(); TransitionalMovie tm = container.Resolve<TransitionalMovie>(); tm.Test1(); string result = tm.Test2(); Console.WriteLine(result); tm.Test3("世界第一等");
動態代理生成類反編譯代碼
動態代理包含例外攔截與事物的全部代碼
public static Object CreateProxyObject(Type InterfaceType, Type ImpType, Type InterceptType, bool inheritMode = true, bool isInterceptAllMethod = true) { string nameOfAssembly = ImpType.Name + "ProxyAssembly"; string nameOfModule = ImpType.Name + "ProxyModule"; string nameOfType = ImpType.Name + "Proxy"; var assemblyName = new AssemblyName(nameOfAssembly); ModuleBuilder moduleBuilder = null; var assembly = AssemblyBuilder.DefineDynamicAssembly(assemblyName, AssemblyBuilderAccess.Run); moduleBuilder = assembly.DefineDynamicModule(nameOfModule); TypeBuilder typeBuilder; if (inheritMode) { typeBuilder = moduleBuilder.DefineType( nameOfType, TypeAttributes.Public, ImpType); } else { typeBuilder = moduleBuilder.DefineType( nameOfType, TypeAttributes.Public, null, new[] { InterfaceType }); } InjectInterceptor(typeBuilder, ImpType, InterceptType, inheritMode, isInterceptAllMethod); var t = typeBuilder.CreateType(); return Activator.CreateInstance(t); } private static void InjectInterceptor(TypeBuilder typeBuilder, Type ImpType, Type InterceptType, bool inheritMode, bool isInterceptAllMethod) { #region 變數定義 // ---- 變數定義 ---- var constructorBuilder = typeBuilder.DefineConstructor( MethodAttributes.Public, CallingConventions.Standard, null); var ilOfCtor = constructorBuilder.GetILGenerator(); //---- 攔截類物件定義 ---- if (InterceptType == null) { InterceptType = typeof(DefaultIntercept); } //宣告 var fieldInterceptor = typeBuilder.DefineField( "_interceptor", InterceptType, FieldAttributes.Private); //賦值 ilOfCtor.Emit(OpCodes.Ldarg_0); ilOfCtor.Emit(OpCodes.Newobj, InterceptType.GetConstructor(new Type[0])); ilOfCtor.Emit(OpCodes.Stfld, fieldInterceptor); #endregion #region 代理物件定義 //---- 實作類物件定義 ---- //宣告 var fieldBeProxy = typeBuilder.DefineField( "_beproxy", ImpType, FieldAttributes.Private); //賦值 ilOfCtor.Emit(OpCodes.Ldarg_0); ilOfCtor.Emit(OpCodes.Newobj, ImpType.GetConstructor(new Type[0])); ilOfCtor.Emit(OpCodes.Stfld, fieldBeProxy); ilOfCtor.Emit(OpCodes.Ret); #endregion // ---- 定義類中的方法 ---- var methodsOfType = ImpType.GetMethods(BindingFlags.Public | BindingFlags.Instance).Where(a => a.IsVirtual).ToArray(); string[] ignoreMethodName = new[] { "GetType", "ToString", "GetHashCode", "Equals" }; for (var i = 0; i < methodsOfType.Length; i++) { #region 方法是否需要攔截判斷，Object內置方法過濾 bool IsMethodIntercept = false; bool IsTransitinal = false; var method = methodsOfType[i]; //---- 過濾Object基類方法,如果是繼承，基類中的屬性get，set方法也要過濾 ---- if (ignoreMethodName.Contains(method.Name) || method.Name.StartsWith("set_") || method.Name.StartsWith("get_")) { continue; } // ---- 判斷方法是否需要攔截 ---- if (isInterceptAllMethod) { if (method.GetCustomAttribute(typeof(IgnoreInterceptAttibute)) == null) { IsMethodIntercept = true; } } else { if (method.GetCustomAttribute(typeof(InterceptAttibute)) != null) { IsMethodIntercept = true; } } // ---- 判斷方法是否需要納入事物管理中 ---- if (method.GetCustomAttribute(typeof(Transitional)) != null) { IsTransitinal = true; } #endregion #region 泛型方法處理 var methodParameterTypes = method.GetParameters().Select(p => p.ParameterType).ToArray(); // ---- 定義方法名與引數 ---- var methodBuilder = typeBuilder.DefineMethod( method.Name, MethodAttributes.Public | MethodAttributes.Virtual, CallingConventions.Standard, method.ReturnType, methodParameterTypes); //如果是泛型方法 if (method.IsGenericMethod) { //獲取所有泛型引數型別定義 Type[] Args = method.GetGenericArguments(); List<string> GenericArgNames = new List<string>(); for (int j = 0; j < Args.Length; j++) { GenericArgNames.Add(Args[j].Name); } //代理類方法生成泛型引數定義 GenericTypeParameterBuilder[] DGP = methodBuilder.DefineGenericParameters(GenericArgNames.ToArray()); //泛型引數約束設定 for (int j = 0; j < DGP.Length; j++) { //泛型引數繼承約束 DGP[j].SetBaseTypeConstraint(Args[j].BaseType); //泛型引數完成介面約束 DGP[j].SetInterfaceConstraints(Args[j].GetInterfaces()); } } #endregion var ilOfMethod = methodBuilder.GetILGenerator(); var methodresult = ilOfMethod.DeclareLocal(typeof(object)); //instance of result //賦值方法結果物件初始值為null ilOfMethod.Emit(OpCodes.Ldnull); ilOfMethod.Emit(OpCodes.Stloc_0); #region 事物攔截開始 if (IsTransitinal) { //開始try模塊 ilOfMethod.BeginExceptionBlock(); //呼叫TransitionManage.StartTransition ilOfMethod.Emit(OpCodes.Call, typeof(TransitionManage).GetMethod("StartTransition")); ilOfMethod.Emit(OpCodes.Ldarg_0); } #endregion #region before攔截 // ---- before ---- if (IsMethodIntercept) { var parameters = ilOfMethod.DeclareLocal(typeof(object[])); ilOfMethod.Emit(OpCodes.Ldc_I4, methodParameterTypes.Length); ilOfMethod.Emit(OpCodes.Newarr, typeof(object)); ilOfMethod.Emit(OpCodes.Stloc, parameters); for (var j = 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.Ldarg_0); ilOfMethod.Emit(OpCodes.Ldfld, fieldInterceptor); //攔截方法引數賦值 if (inheritMode) { //繼承傳遞代理類本身 ilOfMethod.Emit(OpCodes.Ldarg_0); } else { //介面傳遞實作類 ilOfMethod.Emit(OpCodes.Ldarg_0); ilOfMethod.Emit(OpCodes.Ldfld, fieldBeProxy); } ilOfMethod.Emit(OpCodes.Ldstr, method.Name); ilOfMethod.Emit(OpCodes.Ldloc, parameters); //呼叫攔截類中的Before方法 ilOfMethod.Emit(OpCodes.Callvirt, InterceptType.GetMethod("Before")); } #endregion #region 方法執行 // ---- call ---- ////定義實作類區域變數 //var localimpobj = ilOfMethod.DeclareLocal(ImpType); ////new一個實作類的物件 //ilOfMethod.Emit(OpCodes.Newobj, ImpType.GetConstructor(new Type[0])); ////區域變數賦值 //ilOfMethod.Emit(OpCodes.Stloc, localimpobj); ////區域變數出堆疊，等待呼叫 //ilOfMethod.Emit(OpCodes.Ldloc, localimpobj); //方法執行開始時間 var localstart = ilOfMethod.DeclareLocal(typeof(DateTime)); ilOfMethod.Emit(OpCodes.Call, typeof(DateTime).GetMethod("get_Now")); ilOfMethod.Emit(OpCodes.Stloc, localstart); if (inheritMode) { //繼承方法呼叫父類的方法 ilOfMethod.Emit(OpCodes.Ldarg_0); for (var j = 0; j < methodParameterTypes.Length; j++) { ilOfMethod.Emit(OpCodes.Ldarg, j + 1); } ilOfMethod.Emit(OpCodes.Call, ImpType.GetMethod(method.Name)); } else { //介面方法呼叫實作類的方法 ilOfMethod.Emit(OpCodes.Ldarg_0); ilOfMethod.Emit(OpCodes.Ldfld, fieldBeProxy); for (var j = 0; j < methodParameterTypes.Length; j++) { ilOfMethod.Emit(OpCodes.Ldarg, j + 1); } //呼叫方法 ilOfMethod.Emit(OpCodes.Callvirt, ImpType.GetMethod(method.Name)); } var localend = ilOfMethod.DeclareLocal(typeof(DateTime)); ilOfMethod.Emit(OpCodes.Call, typeof(DateTime).GetMethod("get_Now")); ilOfMethod.Emit(OpCodes.Stloc, localend); #endregion #region after攔截 // ---- after ---- if (IsMethodIntercept) { if (method.ReturnType == typeof(void)) { ilOfMethod.Emit(OpCodes.Ldnull); } else { ilOfMethod.Emit(OpCodes.Box, method.ReturnType); } ilOfMethod.Emit(OpCodes.Stloc, methodresult); ilOfMethod.Emit(OpCodes.Ldarg_0); ilOfMethod.Emit(OpCodes.Ldfld, fieldInterceptor); //攔截方法引數賦值 if (inheritMode) { //繼承傳遞代理類本身 ilOfMethod.Emit(OpCodes.Ldarg_0); } else { //介面傳遞實作類 ilOfMethod.Emit(OpCodes.Ldarg_0); ilOfMethod.Emit(OpCodes.Ldfld, fieldBeProxy); } ilOfMethod.Emit(OpCodes.Ldstr, method.Name); ilOfMethod.Emit(OpCodes.Ldloc, methodresult); ilOfMethod.Emit(OpCodes.Ldloc, localstart); ilOfMethod.Emit(OpCodes.Ldloc, localend); ilOfMethod.Emit(OpCodes.Callvirt, InterceptType.GetMethod("After")); } #endregion #region 事物提交及例外捕獲及回滾 if (IsTransitinal) { //呼叫TransitionManage.DoCommit ilOfMethod.Emit(OpCodes.Pop); ilOfMethod.Emit(OpCodes.Call, typeof(TransitionManage).GetMethod("DoCommit")); ilOfMethod.Emit(OpCodes.Ldarg_0); //開始catch模塊 ilOfMethod.BeginCatchBlock(typeof(System.Exception)); //呼叫TransitionManage.DoRollBack Transitional transition = (Transitional)method.GetCustomAttribute(typeof(Transitional)); if (transition.AutoRollBack) { ilOfMethod.Emit(OpCodes.Pop); ilOfMethod.Emit(OpCodes.Call, typeof(TransitionManage).GetMethod("DoRollBack")); } else { //throw例外 ilOfMethod.Emit(OpCodes.Pop); ilOfMethod.Emit(OpCodes.Rethrow); } //結束例外塊 ilOfMethod.EndExceptionBlock(); } #endregion #region 處理回傳值 //呼叫完After方法后,將實作類的方法回傳值的臨時變數再次壓堆疊用作代理方法的回傳 ilOfMethod.Emit(OpCodes.Ldloc, methodresult); // pop the stack if return void if (method.ReturnType == typeof(void)) { ilOfMethod.Emit(OpCodes.Pop); } else { if (method.ReturnType.IsValueType) { ilOfMethod.Emit(OpCodes.Unbox_Any, method.ReturnType); } else { ilOfMethod.Emit(OpCodes.Castclass, method.ReturnType); } } #endregion // complete ilOfMethod.Emit(OpCodes.Ret); } }View Code
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標籤：.NET Core