之前实现了NetCore实现自定义IOC容器注入,在Controller使用事物的过程中思考是否能够像Spring一样通过自定义注解实现事物管理,思路图如下

事物的动作拆分只需要根据当前执行线程划分Connection对象并开启事物即可,重点是在Emit代码织入过程中对异常捕捉的处理
处理过程中主要会用到BeginExceptionBlock开启try代码块,BeginCatchBlock开启catch代码块,EndExceptionBlock结束异常捕捉代码块
创建事物注解Transitional用来标记Controller中需要事物执行的方法
[AttributeUsage(AttributeTargets.Method)] public class Transitional : System.Attribute { public bool AutoRollBack { set; get; } public Transitional() { AutoRollBack = true; } }Emit编织时需要注意异常捕捉时有返回值时建立全局变量返回,执行事物管理器类的静态方法直接使用call,例如 ilOfMethod.Emit(OpCodes.Call, typeof(TransitionManage).GetMethod("DoRollBack")),同时Controller被拦截的方法需要标记Transitional注解且同时是虚方法
被代理类示例
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容器原理可参考c#通过Emit方式实现动态代理
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");动态代理生成类反编译代码


动态代理包含异常拦截与事物的全部代码


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 变量定义 // ---- 变量定义 ---- var constructorBuilder = typeBuilder.DefineConstructor( MethodAttributes.Public, CallingConventions.Standard, null); var ilOfCtor = constructorBuilder.GetILGenerator(); //---- 拦截类对象定义 ---- if (InterceptType == null) { InterceptType = typeof(DefaultIntercept); } //声明 var fieldInterceptor = typeBuilder.DefineField( "_interceptor", InterceptType, FieldAttributes.Private); //赋值 ilOfCtor.Emit(OpCodes.Ldarg_0); ilOfCtor.Emit(OpCodes.Newobj, InterceptType.GetConstructor(new Type[0])); ilOfCtor.Emit(OpCodes.Stfld, fieldInterceptor);
No comments:
Post a Comment