Aop注入有2种方式:动态注入和静态注入,其中动态注入有很多实现了
动态注入有几种方式:
- 利用Remoting的ContextBoundObject或MarshalByRefObject。
- 动态代理(反射)，很多AOP框架都用这种方式。
- MVC的filter，也是反射。
这里主要介绍静态注入
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起初的想法是实现一种功能,自动给对象的属性一个默认值,想来想去没有什么好的解决方法,参考资料后决定使用Mono.Cecil修改生成的程序集来实现!
先定义一个接口
using System; using System.Collections.Generic; using System.Linq; using System.Linq.Expressions; using System.Text; using System.Threading.Tasks; namespace System.Linq { /// <summary> /// 支持注入 /// </summary> /// <typeparam name="T"></typeparam> internal interface IInject<T> { /// <summary> /// 注入属性 /// </summary> /// <typeparam name="TKey"></typeparam> /// <param name="name"></param> /// <param name="value"></param> /// <returns></returns> IInject<T> InjectProperty<TKey>(Expression<Func<T, TKey>> propertyName, Expression<Func<T, TKey>> propertyValue, InjectType type); } }
定义一个描述类:
internal class InjectItem { public string Name { get; set; } /// <summary> /// 表示生成的字段 /// </summary> public FieldDefinition Field { get; set; } /// <summary> /// 标识生成字段成功 /// </summary> public FieldDefinition SetOKField { get; set; } /// <summary> /// 标识 /// </summary> public FieldDefinition ValueField { get; set; } public Type FieldType { get; set; } public Type Type { get; set; } public Delegate Value { get; set; } public MethodReference Method { get; set; } }
定义一个缓存帮助类,存放程序集的一些数据:
using Mono.Cecil; using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; namespace System { internal class CacheHelper { internal static readonly ICache<string, TupleCache<AssemblyDefinition, bool>> _assembly = CacheFactory.CreateCache<string, TupleCache<AssemblyDefinition, bool>>(); internal static readonly List<InjectItem> _setValue = new List<InjectItem>(); /// <summary> /// 得到唯一程序集 /// </summary> /// <param name="type"></param> /// <returns></returns> internal static TupleCache<AssemblyDefinition, bool> GetAssembly(Type type) { var ass = type.Assembly; var path = ass.CodeBase.TrimStart("file:///".ToCharArray()); return _assembly.Get(path, () => { return new TupleCache<AssemblyDefinition, bool>(AssemblyDefinition.ReadAssembly(path), false); }); } } }
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; namespace System { internal class TupleCache<T1, T2> { public TupleCache(T1 item1, T2 item2) { Item1 = item1; Item2 = item2; } public T1 Item1 { get; set; } public T2 Item2 { get; set; } } }
定义一个枚举,标识怎么处理映射:
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; namespace System.Linq { /// <summary> /// 指定注入类型 /// </summary> //[Flags] public enum InjectType { /// <summary> /// 忽略原属性值 /// </summary> IgnoreOldValue = 1, /// <summary> /// 检查原属性默认值 /// </summary> CheckOldValueDefault = 2, /// <summary> /// 当属性值改变时重新赋值 /// </summary> ReadOnValueChanged = 3, /// <summary> /// 当属性值改变时重新赋值(检查属性默认值) /// </summary> ReadOnValueChangedCheckOldValueDefault = 4 } }
接下来是具体实现:
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Reflection.Emit; using System.Linq.Expressions; using System.Reflection; using Mono.Cecil; using System.Collections; using System.Collections.ObjectModel; using Mono.Cecil.Cil; namespace System.Linq { internal class InjectItem { public string Name { get; set; } /// <summary> /// 表示生成的字段 /// </summary> public FieldDefinition Field { get; set; } /// <summary> /// 标识生成字段成功 /// </summary> public FieldDefinition SetOKField { get; set; } /// <summary> /// 标识 /// </summary> public FieldDefinition ValueField { get; set; } /// <summary> /// 字段类型 /// </summary> public Type FieldType { get; set; } /// <summary> /// 属性类型 /// </summary> public Type Type { get; set; } public Delegate Value { get; set; } public MethodReference Method { get; set; } } internal sealed class InjectBase<T> : IInject<T> { /// <summary> /// 生成的字段名 /// </summary> static readonly string _fieldName = "___Inject_Property_Name_{0}___"; static readonly string _setFieldName = "___Inject_Property_Name_{0}___OK"; static readonly string _methodName = "___Inject_Method_CheckDefaultValue___"; Collection<InjectItem> _injectItems = new Collection<InjectItem>(); internal InjectBase() { _type = typeof(T); if (_type.IsNested) { throw new ArgumentException(_type.FullName + " is a private class!"); } _assemby = CacheHelper.GetAssembly(_type); _typeDefinition = GetTypeFromAssembly(); if (_typeDefinition == null) { throw new ArgumentException("type is undefined!"); } } /// <summary> /// 要处理的类型 /// </summary> Type _type; /// <summary> /// 当前类型所对应的Mono.Cecil描述程序集 /// </summary> TupleCache<AssemblyDefinition, bool> _assemby; /// <summary> /// 当前类型对应的Mono.Cecil描述类型 /// </summary> TypeDefinition _typeDefinition; /// <summary> /// 获取类型对应的Mono.Cecil描述类型 /// </summary> /// <returns></returns> TypeDefinition GetTypeFromAssembly() { foreach (var item in _assemby.Item1.Modules) { var type = item.Types.FirstOrDefault(o => o.FullName == _type.FullName); if (type != null) { return type; } } return null; } Tuple<InjectItem, bool> OnInject<TKey>(Expression<Func<T, TKey>> propertyName, Expression<Func<T, TKey>> propertyValue) { //if (!typeof(MemberExpression).IsAssignableFrom(propertyName.Body.GetType()) && propertyName.Body.GetType().Name != "PropertyExpression") if (propertyName.Body.GetType().Name != "PropertyExpression") { throw new ArgumentException("propertyName is not a property expression!"); } var body = propertyName.Body as MemberExpression; string name = body.Member.Name; //指示是否处理过了当前类型 TypeDefinition newType = _assemby.Item1.MainModule.Types.FirstOrDefault(o => o.FullName == InjectMap._classType.Item1 + "." + InjectMap._classType.Item2); //字段 string fieldName = string.Format(_fieldName, name); if (newType != null) { //处理过类型的其他属性了 //看看是否处理了当前属性 var injectItem1 = _injectItems.FirstOrDefault(o => o.Name == fieldName); if (injectItem1 == null) { //没处理 injectItem1 = new InjectItem() { Name = fieldName, Type = _type }; _injectItems.Add(injectItem1); CacheHelper._setValue.Add(injectItem1); } return new Tuple<InjectItem, bool>(injectItem1, true); } _assemby.Item2 = true; //得到属性 var property = _typeDefinition.Properties.FirstOrDefault(o => o.Name == name); var getMethod = property.GetMethod; var setMethod = property.SetMethod; //如果不可读 if (getMethod == null) { throw new ArgumentException("property " + name + " on " + _type.FullName + " is writeonly!"); } var injectItem = _injectItems.FirstOrDefault(o => o.Name == fieldName); if (injectItem == null) { var field = _typeDefinition.Fields.FirstOrDefault(o => o.Name == fieldName); FieldDefinition valueField = null; FieldDefinition setFieldOK = null; if (field == null) { //field = new FieldDefinition(fieldName, Mono.Cecil.FieldAttributes.Private | Mono.Cecil.FieldAttributes.Static, new TypeReference("System", typeof(Func<T, TKey>).Name, ModuleDefinition.ReadModule(Assembly.GetAssembly(typeof(Func<T, TKey>)).Location), new ModuleReference("mscorlib.dll"))); field = new FieldDefinition(fieldName, Mono.Cecil.FieldAttributes.Private | Mono.Cecil.FieldAttributes.Static, _typeDefinition.Module.Import(typeof(Func<T, TKey>))); valueField = new FieldDefinition(fieldName + "Value", Mono.Cecil.FieldAttributes.Private, property.PropertyType); setFieldOK = new FieldDefinition(string.Format(_setFieldName, name), Mono.Cecil.FieldAttributes.Private, _typeDefinition.Module.Import(typeof(bool))); _typeDefinition.Fields.Add(field); _typeDefinition.Fields.Add(valueField); _typeDefinition.Fields.Add(setFieldOK); injectItem = new InjectItem() { Field = field, ValueField = valueField, Name = fieldName, Type = _type, FieldType = body.Member.DeclaringType, SetOKField = setFieldOK, Method = new MethodReference(fieldName, _typeDefinition.Module.Import(property.PropertyType), _typeDefinition.Module.Import(_typeDefinition)) }; _injectItems.Add(injectItem); CacheHelper._setValue.Add(injectItem); } //else //{ // valueField = _typeDefinition.Fields.FirstOrDefault(o => o.Name == fieldName + "Value"); // setFieldOK = _typeDefinition.Fields.FirstOrDefault(o => o.Name == string.Format(_setFieldName, name)); //} } ////DefaultMethod //var checkDefaultMethod = _typeDefinition.Methods.FirstOrDefault(o => o.Name == _methodName); //if (checkDefaultMethod == null) //{ // checkDefaultMethod = new MethodDefinition(_methodName, Mono.Cecil.MethodAttributes.Static | Mono.Cecil.MethodAttributes.Private, _typeDefinition.Module.Import(typeof(bool))); //} return new Tuple<InjectItem, bool>(injectItem, false); } public IInject<T> InjectProperty<TKey>(Expression<Func<T, TKey>> propertyName, Expression<Func<T, TKey>> propertyValue, InjectType type) { //预处理 var item = OnInject(propertyName, propertyValue); //编译值 item.Item1.Value = propertyValue.Compile(); if (item.Item2) { //已处理,不再继续 return this; } var body = propertyName.Body as MemberExpression; string name = body.Member.Name; var fieldName = string.Format(_fieldName, name); var fieldValueName = fieldName + "Value"; //得到属性 var property = _typeDefinition.Properties.FirstOrDefault(o => o.Name == name); var getMethod = property.GetMethod; getMethod.Body.Instructions.Clear(); getMethod.Body.Variables.Add(new VariableDefinition("flag", _typeDefinition.Module.Import(typeof(bool)))); getMethod.Body.Variables.Add(new VariableDefinition(fieldValueName, _typeDefinition.Module.Import(property.PropertyType))); //处理Get属性 if (type == InjectType.CheckOldValueDefault || type == InjectType.ReadOnValueChangedCheckOldValueDefault) { InjectPropertyInternalGetCheckDefault(item.Item1, getMethod, propertyName, propertyValue, type); } else { InjectPropertyInternalGet(item.Item1, getMethod, propertyName, propertyValue, type); } var setMethod = property.SetMethod; if (setMethod != null) { //处理Set属性 setMethod.Body.Instructions.Clear(); if (type == InjectType.CheckOldValueDefault || type == InjectType.ReadOnValueChangedCheckOldValueDefault) { InjectPropertyInternalSetCheckDefault(item.Item1, setMethod, propertyName, propertyValue, type); } else { InjectPropertyInternalSet(item.Item1, setMethod, propertyName, propertyValue, type); } } return this; } IInject<T> InjectPropertyInternalGet<TKey>(InjectItem item, MethodDefinition method, Expression<Func<T, TKey>> propertyName, Expression<Func<T, TKey>> propertyValue, InjectType type) { method.Body.InitLocals = true; var iLProcessor = method.Body.GetILProcessor(); iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Nop); iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ldarg_0); iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ldfld, item.SetOKField); iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ldc_I4_0); //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ldfld, item.Item1.ValueField); //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ldnull); iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ceq); iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Stloc_0); iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ldloc_0); List<Instruction> trueInstruction = new List<Instruction>(); trueInstruction.Add(Instruction.Create(Mono.Cecil.Cil.OpCodes.Nop)); trueInstruction.Add(Instruction.Create(Mono.Cecil.Cil.OpCodes.Ldarg_0)); trueInstruction.Add(Instruction.Create(Mono.Cecil.Cil.OpCodes.Ldsfld, item.Field)); trueInstruction.Add(Instruction.Create(Mono.Cecil.Cil.OpCodes.Ldarg_0)); var invokeMethod = _typeDefinition.Module.Import(typeof(Func<T, TKey>).GetMethod("Invoke")); trueInstruction.Add(Instruction.Create(Mono.Cecil.Cil.OpCodes.Callvirt, invokeMethod)); trueInstruction.Add(Instruction.Create(Mono.Cecil.Cil.OpCodes.Stfld, item.ValueField)); trueInstruction.Add(Instruction.Create(Mono.Cecil.Cil.OpCodes.Ldarg_0)); trueInstruction.Add(Instruction.Create(Mono.Cecil.Cil.OpCodes.Ldc_I4_1)); trueInstruction.Add(Instruction.Create(Mono.Cecil.Cil.OpCodes.Stfld, item.SetOKField)); trueInstruction.Add(Instruction.Create(Mono.Cecil.Cil.OpCodes.Nop)); List<Instruction> falseInstruction = new List<Instruction>(); falseInstruction.Add(Instruction.Create(Mono.Cecil.Cil.OpCodes.Ldarg_0)); falseInstruction.Add(Instruction.Create(Mono.Cecil.Cil.OpCodes.Ldfld, item.ValueField)); falseInstruction.Add(Instruction.Create(Mono.Cecil.Cil.OpCodes.Stloc_1)); iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Brfalse_S, falseInstruction[0]); foreach (var instruction in trueInstruction) { iLProcessor.Append(instruction); } foreach (var instruction in falseInstruction) { iLProcessor.Append(instruction); } Instruction endInstruction = Instruction.Create(Mono.Cecil.Cil.OpCodes.Ldloc_1); iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Br_S, endInstruction); iLProcessor.Append(endInstruction); iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ret); return this; } IInject<T> InjectPropertyInternalGetCheckDefault<TKey>(InjectItem item, MethodDefinition method, Expression<Func<T, TKey>> propertyName, Expression<Func<T, TKey>> propertyValue, InjectType type) { var body = propertyName.Body as MemberExpression; //method.Body.Variables.Add(new VariableDefinition("flag2", _typeDefinition.Module.Import(typeof(bool)))); //if (item.ValueField.FieldType.IsValueType) //{ // method.Body.Variables.Add(new VariableDefinition("defaultValue", _typeDefinition.Module.Import(body.Member.ReflectedType))); //} method.Body.InitLocals = true; var iLProcessor = method.Body.GetILProcessor(); iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Nop); List<Instruction> flag1 = new List<Instruction>(); flag1.Add(Instruction.Create(Mono.Cecil.Cil.OpCodes.Ldarg_0)); flag1.Add(Instruction.Create(Mono.Cecil.Cil.OpCodes.Ldfld, item.SetOKField)); flag1.Add(Instruction.Create(Mono.Cecil.Cil.OpCodes.Ldc_I4_0)); flag1.Add(Instruction.Create(Mono.Cecil.Cil.OpCodes.Ceq)); flag1.Add(Instruction.Create(Mono.Cecil.Cil.OpCodes.Stloc_0)); flag1.Add(Instruction.Create(Mono.Cecil.Cil.OpCodes.Ldloc_0)); //校验默认值 if (!item.ValueField.FieldType.IsValueType) { //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ldloc_2); } else { var equalsMethod = _typeDefinition.Module.Import(typeof(object).GetMethod("Equals", BindingFlags.Static | BindingFlags.Public)); var getHashCodeMethod = _typeDefinition.Module.Import(body.Member.DeclaringType.GetMethod("GetHashCode")); //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ldc_I4_0); //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Bne_Un_S, flag1[0]); //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Stloc_0); //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ldloc_0); //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Bne_Un_S, flag1[0]); //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ldfld, item.SetOKField); //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ldc_I4_0); //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Bne_Un_S, flag1[0]); //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ldarg_2); //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ldfld, item.SetOKField); //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ldc_I4_0); //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ldarg_2); //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ldc_I4_0); //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Callvirt, getHashCodeMethod); //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ldc_I4_0); //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ceq); //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Stloc_0); //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ldloc_0); //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ldc_I4_0); //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Callvirt, getHashCodeMethod); //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ldfld, item.ValueField); //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ldc_I4_0); //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Callvirt, getHashCodeMethod); //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Call, equalsMethod); } foreach (var instruction in flag1) { iLProcessor.Append(instruction); } //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ldfld, item.SetOKField); //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ldc_I4_0); //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ceq); //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Stloc_0); //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ldloc_0); //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ceq); //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Stloc_0); //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ldloc_0); List<Instruction> trueInstruction = new List<Instruction>(); trueInstruction.Add(Instruction.Create(Mono.Cecil.Cil.OpCodes.Nop)); trueInstruction.Add(Instruction.Create(Mono.Cecil.Cil.OpCodes.Ldarg_0)); trueInstruction.Add(Instruction.Create(Mono.Cecil.Cil.OpCodes.Ldsfld, item.Field)); trueInstruction.Add(Instruction.Create(Mono.Cecil.Cil.OpCodes.Ldarg_0)); var invokeMethod = _typeDefinition.Module.Import(typeof(Func<T, TKey>).GetMethod("Invoke")); trueInstruction.Add(Instruction.Create(Mono.Cecil.Cil.OpCodes.Callvirt, invokeMethod)); trueInstruction.Add(Instruction.Create(Mono.Cecil.Cil.OpCodes.Stfld, item.ValueField)); trueInstruction.Add(Instruction.Create(Mono.Cecil.Cil.OpCodes.Ldarg_0)); trueInstruction.Add(Instruction.Create(Mono.Cecil.Cil.OpCodes.Ldc_I4_1)); trueInstruction.Add(Instruction.Create(Mono.Cecil.Cil.OpCodes.Stfld, item.SetOKField)); trueInstruction.Add(Instruction.Create(Mono.Cecil.Cil.OpCodes.Nop)); List<Instruction> falseInstruction = new List<Instruction>(); falseInstruction.Add(Instruction.Create(Mono.Cecil.Cil.OpCodes.Ldarg_0)); falseInstruction.Add(Instruction.Create(Mono.Cecil.Cil.OpCodes.Ldfld, item.ValueField)); falseInstruction.Add(Instruction.Create(Mono.Cecil.Cil.OpCodes.Stloc_1)); iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Brfalse_S, falseInstruction[0]); foreach (var instruction in trueInstruction) { iLProcessor.Append(instruction); } foreach (var instruction in falseInstruction) { iLProcessor.Append(instruction); } Instruction endInstruction = Instruction.Create(Mono.Cecil.Cil.OpCodes.Ldloc_1); iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Br_S, endInstruction); iLProcessor.Append(endInstruction); iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ret); return this; } IInject<T> InjectPropertyInternalSet<TKey>(InjectItem item, MethodDefinition method, Expression<Func<T, TKey>> propertyName, Expression<Func<T, TKey>> propertyValue, InjectType type) { var iLProcessor = method.Body.GetILProcessor(); iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ldarg_0); iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ldarg_1); iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Stfld, item.ValueField); iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ldarg_0); if (type == InjectType.IgnoreOldValue) { iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ldc_I4_1); } else if (type == InjectType.ReadOnValueChanged) { iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ldc_I4_0); } iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Stfld, item.SetOKField); iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ret); //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Stfld, item.ValueField); return this; } IInject<T> InjectPropertyInternalSetCheckDefault<TKey>(InjectItem item, MethodDefinition method, Expression<Func<T, TKey>> propertyName, Expression<Func<T, TKey>> propertyValue, InjectType type) { var iLProcessor = method.Body.GetILProcessor(); iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ldarg_0); iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ldarg_1); iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Stfld, item.ValueField); iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ldarg_0); if (type == InjectType.CheckOldValueDefault) { iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ldc_I4_1); } else if (type == InjectType.ReadOnValueChangedCheckOldValueDefault) { iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ldc_I4_0); } iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Stfld, item.SetOKField); iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Ret); //iLProcessor.Emit(Mono.Cecil.Cil.OpCodes.Stfld, item.ValueField); return this; } } }
以上就是主要代码,接下来给个入口就好了
using Mono.Cecil; using System; using System.Collections.Generic; using System.IO; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Web; namespace System.Linq { public abstract class InjectMap { /// <summary> /// 命名空间和类名,标识程序集已处理 /// </summary> internal static readonly Tuple<string, string> _classType = new Tuple<string, string>("System.Inject", "Inject_Assemby_Over"); static bool _isMap = false; internal static readonly ICache<Type, InjectMap> _cache = CacheFactory.CreateCache<Type, InjectMap>(); /// <summary> /// 创建映射 /// </summary> /// <typeparam name="T"></typeparam> /// <returns></returns> public static InjectMap<T> CreateMap<T>() { var map = _cache.Get(typeof(T), () => InjectMap<T>.Create()) as InjectMap<T>; return map; } /// <summary> /// 结束注入 /// 注意:方法会自动检测是否需要注入数据 /// 如果成功注入数据,则会重启应用程序 /// 注入数据后不会再次注入了 /// </summary> public static void End() { bool reload = false; foreach (var item in CacheHelper._assembly) { if (item.Value.Item2) { reload = true; item.Value.Item1.MainModule.Types.Add(new TypeDefinition(_classType.Item1, _classType.Item2, Mono.Cecil.TypeAttributes.Class | Mono.Cecil.TypeAttributes.Public, item.Value.Item1.MainModule.Import(typeof(object)))); item.Value.Item1.Write(item.Key); } } if (reload) { //会重启程序 CacheHelper._assembly.Flush(); CacheHelper._setValue.Clear(); _isMap = true; if (HttpContext.Current != null) { //HttpRuntime.UnloadAppDomain(); //HttpRuntime.UnloadAppDomain(); File.SetLastWriteTime(System.Web.Hosting.HostingEnvironment.MapPath("~/web.config"), DateTime.Now); //HttpContext.Current.Response.Redirect(HttpContext.Current.Request.Url.ToString()); } return; } else if (!_isMap) { //不重启程序,修改静态字段值 foreach (var item in CacheHelper._setValue) { item.Type.GetField(item.Name, Reflection.BindingFlags.Static | Reflection.BindingFlags.NonPublic).SetValue(null, item.Value); } } _isMap = true; CacheHelper._assembly.Flush(); CacheHelper._setValue.Clear(); } #if DEBUG /// <summary> /// 结束注入 /// </summary> public static void End(string testPath) { bool reload = false; foreach (var item in CacheHelper._assembly) { if (item.Value.Item2) { reload = true; item.Value.Item1.MainModule.Types.Add(new TypeDefinition(_classType.Item1, _classType.Item2, Mono.Cecil.TypeAttributes.Class | Mono.Cecil.TypeAttributes.Public)); item.Value.Item1.Write(item.Key + testPath + ".dll"); } } if (reload) { _isMap = true; if (HttpContext.Current != null) { //HttpRuntime.UnloadAppDomain(); HttpRuntime.UnloadAppDomain(); File.SetLastWriteTime(System.Web.Hosting.HostingEnvironment.MapPath("~/web.config"), DateTime.Now); //HttpContext.Current.Response.Redirect(HttpContext.Current.Request.Url.ToString()); } return; } else if (!_isMap) { foreach (var item in CacheHelper._setValue) { item.Type.GetField(item.Name, Reflection.BindingFlags.Static | Reflection.BindingFlags.NonPublic).SetValue(null, item.Value); } } _isMap = true; } #endif } /// <summary> /// 支持注入 /// </summary> public sealed class InjectMap<T> : InjectMap { InjectMap() { } IInject<T> _inject; internal static InjectMap<T> Create() { InjectMap<T> map = new InjectMap<T>(); map._inject = new InjectBase<T>(); return map; } /// <summary> /// 注入属性值到指定类型中 /// </summary> /// <typeparam name="TKey"></typeparam> /// <param name="propertyName">属性名表达式</param> /// <param name="propertyValue">属性值表达式</param> /// <returns></returns> public InjectMap<T> InjectProperty<TKey>(Expressions.Expression<Func<T, TKey>> propertyName, Expressions.Expression<Func<T, TKey>> propertyValue) { this._inject.InjectProperty(propertyName, propertyValue, InjectType.IgnoreOldValue); return this; } /// <summary> /// 注入属性值到指定类型中 /// </summary> /// <typeparam name="TKey"></typeparam> /// <param name="propertyName">属性名表达式</param> /// <param name="propertyValue">属性值表达式</param> /// <param name="type">注入属性选项</param> /// <returns></returns> public InjectMap<T> InjectProperty<TKey>(Expressions.Expression<Func<T, TKey>> propertyName, Expressions.Expression<Func<T, TKey>> propertyValue, InjectType type) { this._inject.InjectProperty(propertyName, propertyValue, type); return this; } } }
测试:
public class TestClass { public string Name { get; set; } public int Id { get; set; } public bool IsDeleted { get; set; } }
Application_Start中执行代码:
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Web; namespace Dai.CommonLib.WebTest.Models { class Register : IRegister { void IRegister.Register() { InjectMap.CreateMap<TestClass>().InjectProperty(o => o.Name, o => "test").InjectProperty(o => o.IsDeleted, o => !string.IsNullOrEmpty(o.Name)); InjectMap.End(); } } }
控制器代码:
using Dai.CommonLib.WebTest.Models; using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.Mvc; namespace Dai.CommonLib.WebTest.Controllers { public class HomeController : Controller { // GET: Home public ActionResult Index() { TestClass testClass = new TestClass(); return Content(testClass.ToJson()); } } }
看看效果
第一次访问:
{"Name":null,"Id":0,"IsDeleted":false}
此时程序会重启,并且Mono.Cecil会修改已生成好的程序集(如果没有修改过的话)
第二次及以后的访问:
{"Name":"test","Id":0,"IsDeleted":true}
这时候程序集的IL代码已经被修改了
优点:使用方便,可以省去一些麻烦
缺点:目前来看应用场景并不多,并且无法调试(因为程序集与源代码不匹配)!!!
不管怎么说,效果是有的