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本篇文章給大家分享的是有關NetCore中怎么利用Transitional自定義注解事物，小編覺得挺實用的，因此分享給大家學習，希望大家閱讀完這篇文章后可以有所收獲，話不多說，跟著小編一起來看看吧。
之前實現了NetCore實現自定義IOC容器注入，在Controller使用事物的過程中思考是否能夠像Spring一樣通過自定義注解實現事物管理，思路圖如下
事物的動作拆分只需要根據當前執行線程劃分Connection對象并開啟事物即可，重點是在Emit代碼織入過程中對異常捕捉的處理
處理過程中主要會用到BeginExceptionBlock開啟try代碼塊，BeginCatchBlock開啟catch代碼塊，EndExceptionBlock結束異常捕捉代碼塊
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編織時需要注意異常捕捉時有返回值時建立全局變量返回，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方式實現動態代理
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
動態代理包含異常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 變量定義// ---- 變量定義 ----var constructorBuilder = typeBuilder.DefineConstructor(
MethodAttributes.Public, CallingConventions.Standard, null);var ilOfCtor = constructorBuilder.GetILGenerator();//---- 攔截類對象定義 ----if (InterceptType == null)
{
InterceptType = typeof(DefaultIntercept);
}//聲明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 代理對象定義//---- 實現類對象定義 ----//聲明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();// ---- 定義方法名與參數 ----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)
{//獲取所有泛型參數類型定義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參數定義GenericTypeParameterBuilder[] DGP = methodBuilder.DefineGenericParameters(GenericArgNames.ToArray());//泛型參數約束設置for (int j = 0; j < DGP.Length; j++)
{//泛型參數繼承約束DGP[j].SetBaseTypeConstraint(Args[j].BaseType);//泛型參數完成接口約束DGP[j].SetInterfaceConstraints(Args[j].GetInterfaces());
}
}#endregionvar ilOfMethod = methodBuilder.GetILGenerator();var methodresult = ilOfMethod.DeclareLocal(typeof(object)); //instance of result//賦值方法結果對象初始值為nullilOfMethod.Emit(OpCodes.Ldnull);
ilOfMethod.Emit(OpCodes.Stloc_0);#region 事物攔截開始if (IsTransitinal)
{//開始try模塊ilOfMethod.BeginExceptionBlock();//調用TransitionManage.StartTransitionilOfMethod.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);//攔截方法參數賦值if (inheritMode)
{//繼承傳遞代理類本身ilOfMethod.Emit(OpCodes.Ldarg_0);
}else{//接口傳遞實現類ilOfMethod.Emit(OpCodes.Ldarg_0);
ilOfMethod.Emit(OpCodes.Ldfld, fieldBeProxy);
}
ilOfMethod.Emit(OpCodes.Ldstr, method.Name);
ilOfMethod.Emit(OpCodes.Ldloc, parameters);//調用攔截類中的Before方法ilOfMethod.Emit(OpCodes.Callvirt, InterceptType.GetMethod("Before"));
}#endregion#region 方法執行// ---- call ----////定義實現類局部變量//var localimpobj = ilOfMethod.DeclareLocal(ImpType);////new一個實現類的對象//ilOfMethod.Emit(OpCodes.Newobj, ImpType.GetConstructor(new Type[0]));////局部變量賦值//ilOfMethod.Emit(OpCodes.Stloc, localimpobj);////局部變量出棧，等待調用//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)
{//繼承方法調用父類的方法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{//接口方法調用實現類的方法ilOfMethod.Emit(OpCodes.Ldarg_0);
ilOfMethod.Emit(OpCodes.Ldfld, fieldBeProxy);for (var j = 0; j < methodParameterTypes.Length; j++)
{
ilOfMethod.Emit(OpCodes.Ldarg, j + 1);
}//調用方法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);//攔截方法參數賦值if (inheritMode)
{//繼承傳遞代理類本身ilOfMethod.Emit(OpCodes.Ldarg_0);
}else{//接口傳遞實現類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 事物提交及異常捕獲及回滾if (IsTransitinal)
{//調用TransitionManage.DoCommitilOfMethod.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));//調用TransitionManage.DoRollBackTransitional transition = (Transitional)method.GetCustomAttribute(typeof(Transitional));if (transition.AutoRollBack)
{
ilOfMethod.Emit(OpCodes.Pop);
ilOfMethod.Emit(OpCodes.Call, typeof(TransitionManage).GetMethod("DoRollBack"));
}else{//throw異常ilOfMethod.Emit(OpCodes.Pop);
ilOfMethod.Emit(OpCodes.Rethrow);
}//結束異常塊ilOfMethod.EndExceptionBlock();
}#endregion#region 處理返回值//調用完After方法后,將實現類的方法返回值的臨時變量再次壓棧用作代理方法的返回ilOfMethod.Emit(OpCodes.Ldloc, methodresult);// pop the stack if return voidif (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// completeilOfMethod.Emit(OpCodes.Ret);
}
}以上就是NetCore中怎么利用Transitional自定義注解事物，小編相信有部分知識點可能是我們日常工作會見到或用到的。希望你能通過這篇文章學到更多知識。更多詳情敬請關注億速云行業資訊頻道。
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