BindingList<T> and reflection?

[MikeB]

If I have a business object, Order, where Order contains OrderDetails, where OrderDetails is a BindingList<OrderDetail>. How can I create this using relfection?

I have an object builder that dynamically creates the SQL statements and gets a list of order details. Now I need to place those order details in the BindingList<OrderDetail> details member of my object?

/// obj - Container object which holds the BindingList<T> object.
/// property - The PropertyInfo object for the BindingList<T> object.
/// targetType - The type of object that the data reader has and the BindingList<T> should contain.
/// rdr - The date reader with the records?
void LoadObjects(ObjectBase obj, PropertyInfo property, Type targetType, IDataReader rdr)
{
     //// I need to create the binding list???????
     BindingList<????targetType????> list = Activator.CreateInstance(????);

     while(rdr.Read())
     {
          ObjectBase newObj = Activator.CreateInstance(targetType);
          FillObject(newObj, rdr);

         list.Add(newObj);
    }
    property.SetValue(obj, list, null);
}

Any help at all with this?

Mike B

[MadHatter]

try making LoadObjects generic and pass your generic type parameter in as a type parameter to the method instead of as a method parameter.

failing that, you'll have to do it all by reflection instead of creating a known type and calling methods directly on it.

[boudino]

To create an instance of generic type at runtime, you need Type's MakeGenericType() method.

In your case:

Type type = typeof(BindingList<>).MakeGenericType(targetType);

[MikeB]

To create an instance of generic type at runtime, you need Type's MakeGenericType() method.

In your case:

Type type = typeof(BindingList<>).MakeGenericType(targetType);

Thanks, that works!

[Edit]
Ok, it works, but how to I assign it to a property of the "parent" object class. The IBindingList needs an explicit cast. Any ideas?


Mike Bujak

[MikeB]

try making LoadObjects generic and pass your generic type parameter in as a type parameter to the method instead of as a method parameter.

failing that, you'll have to do it all by reflection instead of creating a known type and calling methods directly on it.

Thanks for the reply. What you said works, but I am afraid it doesn't allow me to do all I need to do. There are times when I am loading an object, I may also need to "Eagerly" load some of its child objects and collections, at this point, the type of object is unknown and cannot be passed as a parameter.

Mike B

[MikeB]

Thanks, that works!

[Edit]
Ok, it works, but how to I assign it to a property of the "parent" object class. The IBindingList needs an explicit cast. Any ideas?


Mike Bujak

Should I just declare the members as IBindingList instead of explicit types?