output parameter index[] too high or too low for component

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Permalink Reply by tangchi on October 19, 2016 at 3:23am

Hi Tom

  thank your so much for your solution,but I find it still doesn't work (I didn't completely according to your way to do it),do you put your code in the VS to test it?

Permalink Reply by David Rutten on October 19, 2016 at 4:34am

You are not allowed to change the topology of the network during solutions. That means no deleting objects, no adding/deleting wires, no adding/removing inputs or outputs. You're also not allowed to expire objects during solutions.

Tom's approach is roughly correct, with the exception that he calls CreateOutputs() from within SolveInstance. What you need to do is:

1. Inside SolveInstance figure out which outputs you need for the current solution.
2. If you currently have those outputs, assign data to them and you're done.
3. If you don't, then you must store this information somewhere safe, I recommend a class level variable.
4. You then schedule a solution with a callback to some private method in your component class and you return without assigning the data (or, alternatively, you can assign whatever outputs you do have).
5. When the next solution starts, your callback method will be invoked and this is where you read your local data and modify your outputs accordingly. Now, whenever SolveInstance is called your outputs will match your data.

Do note that some components in Grasshopper whose output topology depends on the input data do not take this approach. Have a look at Explode Tree for example. It will modify the outputs only when the user asks for this via the menu.

Permalink Reply by tangchi on October 21, 2016 at 12:38am

Hi David
thank you for you answer,but did it as your said,but it still doesn't work ,do I misunderstand your mean?(I post my file)

Attachments:

• MyComponent1.cs, 10 KB