C# Custom component that allows user to select Text in rhino and assign to GH component

Hi everyone,

I am creating a custom GH component which just like the geometry curve component (which allows the user to set a curve or several curves) allows the user to select text in Rhino and assign it to a component.

The component will then have a TextEntity instance as its output.

I am doing this by creating a Textgoo which inherits from GH_GeometricGoo - please see the file TextGoo and then by creating a TextParam which takes Textgoo as an argument and inherits from GH_PersistentGeometryParam.

The TextEntity from Rhino is assigned to the Textgoo.value property however at some point this value is lost and therefore when I drop the component onto the canvas I get the following error seen in the picture.

Does anyone have any pointers on what is going on? Please let me know if I haven't made the question clear enough I am new to using Grasshopper SDK.

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Replies to This Discussion

Permalink Reply by djordje on July 28, 2015 at 11:55am

Hi Anton,

I can not help you with your problem.
Just to mention that grasshopper's "Guid" parameter can input text, text dots, points clouds and other types which do not have a specific grasshopper parameter. Once inputted, you can check for their geometry:

textEntity = Rhino.RhinoDoc.ActiveDoc.Objects.Find(txtGuid).Geometry

I apologize for intruding the topic.

Permalink Reply by David Rutten on July 29, 2015 at 3:02am

Since Value can be null, you need to test for null before calling any methods/properties on it. Your ToString() override called directly into Value without checking. That may have been the problem.

Attachments:

TextGoo.cs, 2 KB

Permalink Reply by Anton Szilasi on July 29, 2015 at 3:38am

David,

Thank you for your reply, this does indeed solve the issue of the pop up NullReferenceException but I still haven't solved the issue as to why Value is Null not the instance of the TextEntity that I am selecting in Rhino.

At this point Value is always null. Do you have any ideas about this?

Permalink Reply by David Rutten on July 29, 2015 at 5:38am

Are you sure you want TextEntity? Wouldn't Text3d in the Rhino.Display namespace be better? It seems there is very little support for TextEntity in the SDK and it's also a vaguely abstract type.

Permalink Reply by David Rutten on July 29, 2015 at 6:15am

Attached a cs file which uses Text3d instead of TextEntity. I'm having a lot of trouble with entity, can't get boundingboxes, can't get it to draw, it's a hopeless type.

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