"List<>" data structure in C#.NET component + how to manipulate the output parameter

Hello,

I am having a hard time understanding what is the data structure of a list (of points or lines or Xforms) that comes as an input to C# component.

Actually I have inputted a list of 10 points. I want to access every single point. what are the syntaxes to address them. For example I tried myPoints(3) or myPoints[3] or myPoints.point(3) but they didn't work.

I know there is this method to use a "foreach (On3dPoint in x)" loop, but I wondered if there is a way to precisely address them like an array,to later store them in arrays or use them in known-limit loops.

I have the same question for Xforms, it there a way to access certain points or faces or lines of an Xform?

Why the output type of a C# sharp component could not be changed? Is is possible to output a list of lines and later use them in other GH components?

Many thanks in advance,

Mbnq

Replies to This Discussion

Permalink Reply by Sridevi Koonath on November 7, 2011 at 6:41am

Hello,

[EDIT: I just realised that you are talking about the C# component within grasshopper. I gave you the instructions for making your custom component. If you are unable to figure out what to do from this, let me know. In the meanwhile, I will type out the correct solution. Sorry!!]

First you need to register the input parameter within the RegisterInputParams() method in this manner:

pManager.Register_PointParam("Points List", "P", "List of 3D points", GH_ParamAccess.list);

The GH_Param.Access.xxxx defines whether its a single item, list or a tree input.

In the SolveInstance() method, you can access the list by typing the following:

List<Rhino.Geometry.Point3d> myPointsList = new List<Point3d>();

DA.GetDataList<Rhino.Geometry.Points>(0, myPointsList);

You can either access them as array by doing this (what I prefer):

for (int index = 0; index < myPointsList.Count; index++)

{

Point3d option1 = myPointsList[index];

//or

Point3d option2 = myPointsList.ElementAt(index);

}

Or in this way:

Point3d[] myPointsArray = myPointsList.ToArray(); //Then use a for loop again

Permalink Reply by Sridevi Koonath on November 7, 2011 at 7:14am

Here you go! Hope it is clear now.

And sorry about the confusion earlier!

Attachments:

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Permalink Reply by M N on November 7, 2011 at 8:02am

Great, many thanks, that works pretty well. And I should say yes the first answer was so much technical for me.

The only thing I needed was to translate your definition to a .NET version using onLine and on3dPoint. And now it works well.

Now I am heading for Xforms and ...

But meanwhile I came to this question what is the difference of C# and C#.NET components other than just the way we call rhino classes?

Permalink Reply by Sridevi Koonath on November 7, 2011 at 9:14am

Haha....I just noticed that there were two different C# components :-D

From what I can see, the difference is with the libraries that the components are using. The Legacy component uses the older version of the Rhino SDK and also doesn't include the GH_IO library. So it seems like the C# component with the newer version has more features/is more flexible than the Legacy component.

Permalink Reply by M N on November 8, 2011 at 7:00am

Yes it seems so, and so far the namings are pretty organized and logical!

Just after reading this I am getting back to what you told in the first answer, still far from making my own component. But I would try soon maybe!

All in all thanks for your great responds,

Mobasher

Permalink Reply by Sridevi Koonath on November 9, 2011 at 4:07am

Glad to help :)

If you plan to write your own component, you should download the Grasshopper SDK (Grasshopper -> Help -> Download SDK Help), it contains a few examples as well.

Good luck!

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