Is Gh_Structure.DataList Implemented?

Hi all,

I'm wondering if I'm doing something wrong... The Grasshopper documentation outlines a few properties and methods, but I can't seem to make use of them. For example, the property "DataList" on an object of type GH_Structure:

http://developer.rhino3d.com/api/grasshopper/html/T_Grasshopper_Ker...

Attachments:

documentation.PNG, 117 KB
Error List.PNG, 42 KB

Replies to This Discussion

Permalink Reply by Michael Pryor on June 14, 2017 at 9:03am

i think it means you're missing that namespace. Are you using the GH Assembly template for visual studio? It doesn't have all the namespaces there by default. According to your link that class needs this namespace: using Grasshopper.Kernel.Data; so add that line to your namespaces.

Permalink Reply by Matthew Breau on June 14, 2017 at 9:20am

HI Michael, I forgot to mention in my initial question, these are my references in that file:

using System;
using System.Linq;
using System.Collections.Generic;

using Grasshopper;
using Grasshopper.Kernel;
using Grasshopper.Kernel.Data;
using Grasshopper.Kernel.Types;

using Rhino.Geometry;

Visual Studio code hints for the object (see screenshot), it just won't suggest/ can't find certain methods and properties.

Attachments:

hinting.PNG, 41 KB

Permalink Reply by David Rutten on June 14, 2017 at 10:46am

It's a property with an indexer. That only works in VB, not C#. You can probably access the get_DataList() method though which is C#'s way of dealing with this.

Permalink Reply by Matthew Breau on June 14, 2017 at 11:40am

Ah, okay, thanks David.

Permalink Reply by Andrew Heumann on June 14, 2017 at 2:52pm

This didn't work for me - but looking at the documentation it appears this DataList property in vb is covered by the [ ] accessor in c# - so instead of structure.DataList[i] or structure.get_DataList(i) you just call structure[i]. See how it's indicated with keyword "this" in the C# representation:

public List<T> this[int index ] { get; }

Permalink Reply by Andrew Heumann on June 14, 2017 at 2:53pm

On the other hand, the other property accessor "DataItem" does appear to work as david is describing in c# - meaning you have to call structure.get_DataItem(i).

Permalink Reply by Matthew Breau on June 15, 2017 at 7:46am

Thanks Andrew, I've been experimenting

Posted a screenshot of findings, in case it helps anyone in the future

Attachments: