"You cannot call IGN_DataAccess.GetDataList() on an Item Parameter"

I'm getting "You cannot call IGN_DataAccess.GetDataList() on an Item Parameter"

and I have DA.GetDataList, I'm going crazy.

But I have included GH_ParamAccess.list in the code below, what is going on.....

Protected Overrides Sub RegisterInputParams(ByVal pManager AsGrasshopper.Kernel.GH_Component.GH_InputParamManager)

pManager.Register_MeshParam("Mesh", "meshObject", "Mesh To Export",GH_ParamAccess.list)

End Sub

Protected Overrides Sub SolveInstance(ByVal DA As Grasshopper.Kernel.IGH_DataAccess)

Dim meshObject As New List(Of Rhino.Geometry.Mesh)

If (Not DA.GetDataList(0, meshObject)) Then Return

Replies to This Discussion

Permalink Reply by Jon Mirtschin on May 9, 2011 at 12:05pm

Are you creating a brand new component on the canvas? If it is a component that was saved with a previous version of the component that wasn't extracting a list you will still get this error message when opening the grasshopper document. Delete it and try adding it again.

Permalink Reply by Carson Smuts on May 9, 2011 at 12:13pm

Hmm, does it retain a preferences list of components, that I can delete, I tried deleting it and adding it, that does not work, I'll try it though

Permalink Reply by Carson Smuts on May 9, 2011 at 12:18pm

Should I change the System.guid to something else?

Permalink Reply by Carson Smuts on May 9, 2011 at 12:27pm

OK that worked, what the hell....... I generated a brand new GUID yesterday, how can this be the problem...... does grasshopper retain guid ids in a preference file?

Permalink Reply by Jon Mirtschin on May 9, 2011 at 12:33pm

I can't see anything wrong with your code and the symptom matched what I've seen in the past with this. Changing the guid would certainly force you to replace the component.

I pasted your code into this sample component that worked fine for me.

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