How can we get control points/knot vector/basis function information from step file?

Hello,

I'm new to opencascade and i have a problem while using opencascade import step files.

I can import the step file and use explorer to iterate over each shape, but how can I get the geometry information of the model in the step file? Such as control points, node vectors, basis functions, etc.

Below the attachments is the code for how I do the traversal, which uses a map to hold each subtype. When I complete the traversal and output the results in the map, it seems that the output is topology information. How can I output information such as control point node vectors?

Please help me. Thanks and kind regards