一，emit 实现动态类，动态实现接口，或者继承某个类， 或者作为接口的远程调用rpc 的参考
public class DynamicProxyGenerator { private const string DynamicAssemblyName = "DynamicAssembly";//动态程序集名称 private const string DynamicModuleName = "DynamicAssemblyModule"; private const string DynamicModuleDllName = "DynamicAssembly.dll";//动态模块名称 private const string ProxyClassNameFormater = "{0}Proxy"; private const string ModifiedPropertyNamesFieldName = "ModifiedPropertyNames"; private const MethodAttributes GetSetMethodAttributes = MethodAttributes.Public | MethodAttributes.SpecialName | MethodAttributes.CheckAccessOnOverride | MethodAttributes.Virtual | MethodAttributes.HideBySig; /// <summary> /// 创建动态程序集,返回AssemblyBuilder /// </summary> /// <param name="isSavaDll"></param> /// <returns></returns> private static AssemblyBuilder DefineDynamicAssembly(bool isSavaDll = false) { //动态创建程序集 AssemblyName DemoName = new AssemblyName(DynamicAssemblyName); AssemblyBuilderAccess assemblyBuilderAccess = isSavaDll ? AssemblyBuilderAccess.RunAndSave : AssemblyBuilderAccess.Run; AssemblyBuilder dynamicAssembly = AppDomain.CurrentDomain.DefineDynamicAssembly(DemoName, assemblyBuilderAccess); return dynamicAssembly; } /// <summary> /// 创建动态模块,返回ModuleBuilder /// </summary> /// <param name="isSavaDll"></param> /// <returns>ModuleBuilder</returns> private static ModuleBuilder DefineDynamicModule(AssemblyBuilder dynamicAssembly, bool isSavaDll = false) { ModuleBuilder moduleBuilder = null; //动态创建模块 if (isSavaDll) moduleBuilder = dynamicAssembly.DefineDynamicModule(DynamicModuleName, DynamicModuleDllName); else moduleBuilder = dynamicAssembly.DefineDynamicModule(DynamicModuleName); return moduleBuilder; } /// <summary> /// 创建动态代理类,重写属性Get Set 方法,并监控属性的Set方法,把变更的属性名加入到list集合中,需要监控的属性必须是virtual /// 如果你想保存修改的属性名和属性值,修改Set方法的IL实现 /// </summary> /// <typeparam name="T"></typeparam> /// <param name="isSavaDynamicModule"></param> /// <returns></returns> public static T CreateDynamicProxy<T>(bool isSavaDynamicModule = false) { // Type modifiedPropertyNamesType = typeof(HashSet<string>); Type typeNeedProxy = typeof(T); AssemblyBuilder assemblyBuilder = DefineDynamicAssembly(isSavaDynamicModule); //动态创建模块 ModuleBuilder moduleBuilder = DefineDynamicModule(assemblyBuilder, isSavaDynamicModule); string proxyClassName = string.Format(ProxyClassNameFormater, typeNeedProxy.Name); //动态创建类代理 TypeBuilder typeBuilderProxy = moduleBuilder.DefineType(proxyClassName, TypeAttributes.Public, typeNeedProxy); //定义一个变量存放属性变更名 // FieldBuilder fbModifiedPropertyNames = typeBuilderProxy.DefineField(ModifiedPropertyNamesFieldName, modifiedPropertyNamesType, FieldAttributes.Public); /* * 构造函数 实例化 ModifiedPropertyNames,生成类似于下面的代码 ModifiedPropertyNames = new List<string>(); */ //ConstructorBuilder constructorBuilder = typeBuilderProxy.DefineConstructor(MethodAttributes.Public, CallingConventions.Standard, null); //ILGenerator ilgCtor = constructorBuilder.GetILGenerator(); //ilgCtor.Emit(OpCodes.Ldarg_0);//加载当前类 //ilgCtor.Emit(OpCodes.Newobj, modifiedPropertyNamesType.GetConstructor(new Type[0]));//实例化对象入栈 //ilgCtor.Emit(OpCodes.Stfld, fbModifiedPropertyNames);//设置fbModifiedPropertyNames值,为刚入栈的实例化对象 //ilgCtor.Emit(OpCodes.Ret);//返回 //获取被代理对象的所有属性,循环属性进行重写 PropertyInfo[] properties = typeNeedProxy.GetProperties(); //PropertyInfo[] addpro = typeof(BaseAddPropertie).GetProperties(); //var listpro = properties.ToList(); //listpro.AddRange(addpro); //properties = listpro.ToArray(); foreach (PropertyInfo propertyInfo in properties) { string propertyName = propertyInfo.Name; Type typePepropertyInfo = propertyInfo.PropertyType; //动态创建字段和属性 FieldBuilder fieldBuilder = typeBuilderProxy.DefineField("_" + propertyName, typePepropertyInfo, FieldAttributes.Private); PropertyBuilder propertyBuilder = typeBuilderProxy.DefineProperty(propertyName, PropertyAttributes.None, typePepropertyInfo, null); //重写属性的Get Set方法 var methodGet = typeBuilderProxy.DefineMethod("get_" + propertyName, MethodAttributes.Private | MethodAttributes.SpecialName | MethodAttributes.CheckAccessOnOverride | MethodAttributes.Virtual | MethodAttributes.HideBySig, typePepropertyInfo, Type.EmptyTypes); var methodSet = typeBuilderProxy.DefineMethod("set_" + propertyName, MethodAttributes.Private | MethodAttributes.SpecialName | MethodAttributes.CheckAccessOnOverride | MethodAttributes.Virtual | MethodAttributes.HideBySig, null, new Type[] { typePepropertyInfo }); //il of get method var ilGetMethod = methodGet.GetILGenerator(); ilGetMethod.Emit(OpCodes.Ldarg_0); ilGetMethod.Emit(OpCodes.Ldfld, fieldBuilder); ilGetMethod.Emit(OpCodes.Ret); //il of set method ILGenerator ilSetMethod = methodSet.GetILGenerator(); ilSetMethod.Emit(OpCodes.Ldarg_0); ilSetMethod.Emit(OpCodes.Ldarg_1); ilSetMethod.Emit(OpCodes.Stfld, fieldBuilder); //ilSetMethod.Emit(OpCodes.Ldarg_0); //ilSetMethod.Emit(OpCodes.Ldfld, fbModifiedPropertyNames); // ilSetMethod.Emit(OpCodes.Ldstr, propertyInfo.Name); // ilSetMethod.Emit(OpCodes.Callvirt, modifiedPropertyNamesType.GetMethod("Add", new Type[] { typeof(string) })); //ilSetMethod.Emit(OpCodes.Pop); ilSetMethod.Emit(OpCodes.Ret); //设置属性的Get Set方法 propertyBuilder.SetGetMethod(methodGet); propertyBuilder.SetSetMethod(methodSet); } //使用动态类创建类型 Type proxyClassType = typeBuilderProxy.CreateType(); //保存动态创建的程序集 if (isSavaDynamicModule) assemblyBuilder.Save(DynamicModuleDllName); //创建类实例 var instance = Activator.CreateInstance(proxyClassType); return (T)instance; } /// <summary> /// 创建动态代理类,重写属性Get Set 方法,并监控属性的Set方法,把变更的属性名加入到list集合中,需要监控的属性必须是virtual /// 如果你想保存修改的属性名和属性值,修改Set方法的IL实现 /// </summary> /// <typeparam name="T"></typeparam> /// <param name="isSavaDynamicModule"></param> /// <returns></returns> public static Type CreateDynamicProxyNewTest<T,I>(bool isSavaDynamicModule = false) { // Type modifiedPropertyNamesType = typeof(HashSet<string>); Type typeNeedProxy = typeof(T); AssemblyBuilder assemblyBuilder = DefineDynamicAssembly(isSavaDynamicModule); //动态创建模块 ModuleBuilder moduleBuilder = DefineDynamicModule(assemblyBuilder, isSavaDynamicModule); string proxyClassName = string.Format(ProxyClassNameFormater, typeNeedProxy.Name); //动态创建类代理 TypeBuilder typeBuilderProxy = moduleBuilder.DefineType(proxyClassName, TypeAttributes.Public, typeof(T), new Type[] { typeof(I) }); //定义一个变量存放属性变更名 // FieldBuilder fbModifiedPropertyNames = typeBuilderProxy.DefineField(ModifiedPropertyNamesFieldName, modifiedPropertyNamesType, FieldAttributes.Public); /* * 构造函数 实例化 ModifiedPropertyNames,生成类似于下面的代码 ModifiedPropertyNames = new List<string>(); */ //ConstructorBuilder constructorBuilder = typeBuilderProxy.DefineConstructor(MethodAttributes.Public, CallingConventions.Standard, null); //ILGenerator ilgCtor = constructorBuilder.GetILGenerator(); //ilgCtor.Emit(OpCodes.Ldarg_0);//加载当前类 //ilgCtor.Emit(OpCodes.Newobj, modifiedPropertyNamesType.GetConstructor(new Type[0]));//实例化对象入栈 //ilgCtor.Emit(OpCodes.Stfld, fbModifiedPropertyNames);//设置fbModifiedPropertyNames值,为刚入栈的实例化对象 //ilgCtor.Emit(OpCodes.Ret);//返回 //获取被代理对象的所有属性,循环属性进行重写 //PropertyInfo[] properties = typeNeedProxy.GetProperties(); PropertyInfo[] properties = typeof(I).GetProperties(); foreach (PropertyInfo propertyInfo in properties) { string propertyName = propertyInfo.Name; Type typePepropertyInfo = propertyInfo.PropertyType; //动态创建字段和属性 FieldBuilder fieldBuilder = typeBuilderProxy.DefineField("_" + propertyName, typePepropertyInfo, FieldAttributes.Private); PropertyBuilder propertyBuilder = typeBuilderProxy.DefineProperty(propertyName, PropertyAttributes.SpecialName, typePepropertyInfo, null); //var ttsoveride = MethodAttributes.Public | MethodAttributes.SpecialName | MethodAttributes.Virtual | MethodAttributes.HideBySig; var ttp= MethodAttributes.Public | MethodAttributes.HideBySig | MethodAttributes.NewSlot | MethodAttributes.Virtual | MethodAttributes.Final; //重写属性的Get Set方法 var methodGet = typeBuilderProxy.DefineMethod("get_" + propertyName, ttp, typePepropertyInfo, Type.EmptyTypes); var methodSet = typeBuilderProxy.DefineMethod("set_" + propertyName, ttp, null, new Type[] { typePepropertyInfo }); //il of get method var ilGetMethod = methodGet.GetILGenerator(); ilGetMethod.Emit(OpCodes.Ldarg_0); ilGetMethod.Emit(OpCodes.Ldfld, fieldBuilder); ilGetMethod.Emit(OpCodes.Ret); //il of set method ILGenerator ilSetMethod = methodSet.GetILGenerator(); ilSetMethod.Emit(OpCodes.Ldarg_0); ilSetMethod.Emit(OpCodes.Ldarg_1); ilSetMethod.Emit(OpCodes.Stfld, fieldBuilder); //ilSetMethod.Emit(OpCodes.Ldarg_0); //ilSetMethod.Emit(OpCodes.Ldfld, fbModifiedPropertyNames); // ilSetMethod.Emit(OpCodes.Ldstr, propertyInfo.Name); // ilSetMethod.Emit(OpCodes.Callvirt, modifiedPropertyNamesType.GetMethod("Add", new Type[] { typeof(string) })); //ilSetMethod.Emit(OpCodes.Pop); ilSetMethod.Emit(OpCodes.Ret); //设置属性的Get Set方法 propertyBuilder.SetGetMethod(methodGet); propertyBuilder.SetSetMethod(methodSet); } //使用动态类创建类型 Type proxyClassType = typeBuilderProxy.CreateType(); //保存动态创建的程序集 if (isSavaDynamicModule) assemblyBuilder.Save(DynamicModuleDllName); //创建类实例 //var instance = Activator.CreateInstance(proxyClassType); return proxyClassType; } /// <summary> /// 获取属性的变更名称, /// 此处只检测调用了Set方法的属性,不会检测值是否真的有变 /// </summary> /// <param name="obj"></param> /// <returns></returns> public static HashSet<string> GetModifiedProperties(object obj) { FieldInfo fieldInfo = obj.GetType().GetField(ModifiedPropertyNamesFieldName); if (fieldInfo == null) return null; object value = fieldInfo.GetValue(obj); return value as HashSet<string>; } }
参考资料： https://www.cnblogs.com/viclgd/archive/2011/03/28/1998122.html
https://blog.csdn.net/lishuangquan1987/article/details/84312514