Change Pitch of Helix Example (C#)

This example shows how to change the pitch of a helix.

//-------------------------------------------------------
// Preconditions:
// 1. Open a part containing a helix feature.
// 2. Select the helix feature.
// 3. Open the Immediate window.
//
// Postconditions:
// 1. Modifies the pitch of selected helix feature.
// 2. Gets the name of helix feature, original pitch, and
//    modified pitch values.
// 3. Examine the Immediate window and graphics area.
//--------------------------------------------------------
using SolidWorks.Interop.sldworks;
using SolidWorks.Interop.swconst;
using System;
using System.Diagnostics;

namespace PitchHelixFeatureDataCSharp.csproj
{

    partial class SolidWorksMacro
    {

        public void Main()
        {

            ModelDoc2 swModel = default(ModelDoc2);
            SelectionMgr swSelMgr = default(SelectionMgr);
            Feature swFeat = default(Feature);
            HelixFeatureData swHelix = default(HelixFeatureData);
            bool bRet = false;

            swModel = (ModelDoc2)swApp.ActiveDoc;
            swSelMgr = (SelectionMgr)swModel.SelectionManager;
            swFeat = (Feature)swSelMgr.GetSelectedObject6(1, -1);
            swHelix = (HelixFeatureData)swFeat.GetDefinition();


            Debug.Print("Feature = " + swFeat.Name);
            Debug.Print(" Original pitch = " + swHelix.Pitch * 1000.0 + " mm");

            // Change the pitch value
            swHelix.Pitch = 1.25 * swHelix.Pitch;
            Debug.Print(" Modified pitch = " + swHelix.Pitch * 1000.0 + " mm");

            // Apply the change
            bRet = swFeat.ModifyDefinition(swHelix, swModel, null);

            Debug.Assert(bRet);
        }

        /// <summary>
        /// The SldWorks swApp variable is pre-assigned for you.
        /// </summary>
        public SldWorks swApp;


    }
}