private object GetService(ServiceMetadata serviceMetadata)
{
for (int i = 0; i < serviceMetadata.ArgumentsLength; i++)
{
serviceMetadata.ArgumentArray[i] = this.GetService(serviceMetadata.ArgumentMetadataArray[i]);
}
return(serviceMetadata.NewObj(serviceMetadata.ArgumentArray));
}
public void AddService <TService, TImpl>() where TService : class where TImpl : class
{
Type serviceType = typeof(TService);
ServiceMetadata serviceMetadata = new ServiceMetadata();
serviceMetadata.ImplType = typeof(TImpl);
serviceMetadata.Constructor = serviceMetadata.ImplType.GetConstructors()[0];
serviceMetadata.ParameterTypes = serviceMetadata.Constructor.GetParameters().Select(p => p.ParameterType).ToArray();
serviceMetadata.ArgumentsLength = serviceMetadata.ParameterTypes.Length;
serviceMetadata.ArgumentArray = new object[serviceMetadata.ArgumentsLength];
serviceMetadata.ArgumentMetadataArray = new ServiceMetadata[serviceMetadata.ArgumentsLength];
serviceMetadata.NewObj = this.CreateDelegate(serviceMetadata);
this.serviceTypeToMetadata.Add(serviceType, serviceMetadata);
}
public override NewObjDelegate CreateDelegate(ServiceMetadata serviceMetadata)
{
var parametersExpr = Expression.Parameter(typeof(object[]));
var constructorArgumentList = new List <Expression>();
for (int i = 0; i < serviceMetadata.ParameterTypes.Length; i++)
{
var indexExpr = Expression.Constant(i);
var arrayItemExpr = Expression.ArrayIndex(parametersExpr, indexExpr);
var castExpr = Expression.Convert(arrayItemExpr, serviceMetadata.ParameterTypes[i]);
constructorArgumentList.Add(castExpr);
}
var newExpr = Expression.New(serviceMetadata.Constructor, constructorArgumentList.ToArray());
var lambda = Expression.Lambda <NewObjDelegate>(newExpr, parametersExpr);
var newDelegate = lambda.Compile();
return(newDelegate);
}
public override NewObjDelegate CreateDelegate(ServiceMetadata serviceMetadata)
{
DynamicMethod dynamicMethod = new DynamicMethod(
"NewInstance",
typeof(object),
new Type[] { typeof(object[]) });
var il = dynamicMethod.GetILGenerator();
for (int i = 0; i < serviceMetadata.ParameterTypes.Length; i++)
{
il.Emit(OpCodes.Ldarg_0);
il.Emit(OpCodes.Ldc_I4, i);
il.Emit(OpCodes.Ldelem_Ref);
il.Emit(OpCodes.Castclass, serviceMetadata.ParameterTypes[i]);
}
il.Emit(OpCodes.Newobj, serviceMetadata.Constructor);
il.Emit(OpCodes.Ret);
var newObj = (NewObjDelegate)dynamicMethod.CreateDelegate(typeof(NewObjDelegate));
return(newObj);
}
public object GetService(Type serviceType)
{
ServiceMetadata serviceMetadata = this.serviceTypeToMetadata[serviceType];
return(this.GetService(serviceMetadata));
}
public abstract NewObjDelegate CreateDelegate(ServiceMetadata serviceMetadata);
