方法：リフレクトを使用して自己参照型プロパティを定義する方法C＃

Question

自己参照型コレクションプロパティを定義する方法は？ タイプReflection Type Builderでビルドします。

public class Sample 
{ 
    public Sample() 
    { 
     Items = new List<Sample>(); 
    } 
    public List<Sample> Items { get; set; } 
    Public void AddSample(Sample item) 
    { 
     items.Add(item); 
    } 
} 

コード

は、私はあなたがフィールドを発することによって、手動で「バッキングフィールド」を定義して、プロパティのゲッターとセッターを定義する必要が

AppDomain myDomain = AppDomain.CurrentDomain; 
AssemblyName myAsmName = new AssemblyName("GenericEmit"); 
AssemblyBuilder myAssembly = myDomain.DefineDynamicAssembly(myAsmName, AssemblyBuilderAccess.RunAndSave); 

ModuleBuilder myModule = myAssembly.DefineDynamicModule(myAsmName.Name, myAsmName.Name + ".dll"); 
TypeBuilder myType = myModule.DefineType("Sample", TypeAttributes.Public); 
Type listOf = typeof(List<>); 
Type selfContained = listOf.MakeGenericType(myType); 
myType.DefineProperty("Items", PropertyAttributes.None, selfContained, null);     
Type type= myType.CreateType(); 
Activator.CreateInstance(type); 
myAssembly.Save(myAsmName.Name + ".dll"); 

Answer 1

を書きます。

AppDomain myDomain = AppDomain.CurrentDomain; 
AssemblyName myAsmName = new AssemblyName("GenericEmit"); 
AssemblyBuilder myAssembly = myDomain.DefineDynamicAssembly(myAsmName, AssemblyBuilderAccess.RunAndSave); 

ModuleBuilder myModule = myAssembly.DefineDynamicModule(myAsmName.Name, myAsmName.Name + ".dll"); 
TypeBuilder myType = myModule.DefineType("Sample", TypeAttributes.Public); 
Type listOf = typeof(List<>); 
Type selfContained = listOf.MakeGenericType(myType); 

//define a backingfield 
FieldBuilder field = myType.DefineField("<Items>_BackingField", selfContained, FieldAttributes.Private); 

//define a parameterless constructor to initialize the field. 
ConstructorBuilder constructor = myType.DefineConstructor(MethodAttributes.Public, CallingConventions.HasThis, Type.EmptyTypes); 
ILGenerator constructorBody = constructor.GetILGenerator(); 
constructorBody.Emit(OpCodes.Ldarg_0); 
constructorBody.Emit(OpCodes.Call, typeof(object).GetConstructor(Type.EmptyTypes)); 
constructorBody.Emit(OpCodes.Ldarg_0); 
constructorBody.Emit(OpCodes.Newobj, TypeBuilder.GetConstructor(selfContained, listOf.GetConstructor(Type.EmptyTypes))); 
constructorBody.Emit(OpCodes.Stfld, field); 
constructorBody.Emit(OpCodes.Ret); 

//define the getter 
MethodBuilder getter = myType.DefineMethod("get_Items", MethodAttributes.Public | MethodAttributes.HideBySig, selfContained, Type.EmptyTypes); 
ILGenerator getterBody = getter.GetILGenerator(); 
getterBody.Emit(OpCodes.Ldarg_0); 
getterBody.Emit(OpCodes.Ldfld, field); 
getterBody.Emit(OpCodes.Ret); 

//define the setter 
MethodBuilder setter = myType.DefineMethod("set_Items", MethodAttributes.Public | MethodAttributes.HideBySig, typeof(void), new Type[] { selfContained }); 
ILGenerator setterBody = setter.GetILGenerator(); 
setterBody.Emit(OpCodes.Ldarg_0); 
setterBody.Emit(OpCodes.Ldarg_1); 
setterBody.Emit(OpCodes.Stfld, field); 
setterBody.Emit(OpCodes.Ret); 

PropertyBuilder property = myType.DefineProperty("Items", PropertyAttributes.None, selfContained, null); 

//Bind getter and setter 
property.SetGetMethod(getter); 
property.SetSetMethod(setter); 

//AddSample method 
var addSampleMethod = myType.DefineMethod("AddSample", MethodAttributes.Private, CallingConventions.HasThis, typeof(void), new Type[] { myType }}; 
var addSampleMethodBody = addSampleMethod.GetILGenerator(); 
addSampleMethodBody.Emit(OpCodes.Ldarg_0); 
addSampleMethodBody.Emit(OpCodes.Ldfld, field); 
addSampleMethodBody.Emit(OpCodes.Ldarg_1); 
addSampleMethodBody.Emit(OpCodes.Callvirt, TypeBuilder.GetMethod(selfContained, typeof(List<>).GetMethod("Add")); 
addSampleMethodBody.Emit(OpCodes.Ret); 

Type type = myType.CreateType(); 
myAssembly.Save(myAsmName.Name + ".dll"); 

var sample = Activator.CreateInstance(type);