Add Component and Mate (C#)

//---------------------------------------------------------------------
// Preconditions: Open
// install_dir\Program Files\SolidWorks\samples\tutorial\toolbox\lens_mount.sldasm
//
// Postconditions:
// 1. The specified component, camtest.sldprt, and a mate,
//    top_coinc_camtest-1, are added to the assembly.
// 2. Examine the FeatureManager design tree to verify the mate.
//
// NOTE: Because the models are used elsewhere, do not
// save any changes when closing them.
//---------------------------------------------------------------------

using SolidWorks.Interop.sldworks;
using SolidWorks.Interop.swconst;
using System;
using System.Diagnostics;
using System.Windows.Forms;

namespace AssemblyDocAddComponentAndMate.csproj
{
    partial class SolidWorksMacro
    {
        ModelDoc2 swModel;
        ModelDocExtension swDocExt;
        AssemblyDoc swAssy;
        string tmpPath;
        ModelDoc2 tmpObj;
        bool boolstat;
        Component2 swcomponent;
        Feature matefeature;
        string MateName;
        string FirstSelection;
        string SecondSelection;
        swMateAlign_e Alignment;
        string strCompName;
        string AssemblyTitle;
        string AssemblyName;
        int errors;
        int warnings;
        int mateError;

        public void Main()
        {

            swModel = (ModelDoc2)swApp.ActiveDoc;

            // Get title of assembly document
            AssemblyTitle = swModel.GetTitle();

            // Split the title into two strings using the period (.) as the delimiter
            string[] strings = AssemblyTitle.Split(new Char[] { '.' });

            // Use AssemblyName when mating the component with the assembly
            AssemblyName = (string)strings[0];

            Debug.Print(AssemblyName);

            boolstat = true;

            string strCompModelname = null;

            strCompModelname = "camtest.sldprt";

            // Because the component resides in the same folder as the assembly, get
            // the assembly's path, strip out the assembly filename, concatenate
            // the rest of the path to the component filename, and use this string to
            // open the component
            tmpPath = swModel.GetPathName();
            int idx;
            idx = tmpPath.LastIndexOf("lens_mount.sldasm");
            string compPath;
            tmpPath = tmpPath.Substring(0, (idx));
            compPath = string.Concat(tmpPath, strCompModelname);

            // Open the component
            tmpObj = (ModelDoc2)swApp.OpenDoc6(compPath, (int)swDocumentTypes_e.swDocPART, 0, "", ref errors, ref warnings);

            // Check to see if the file is read-only or cannot be found; display error
            // messages if either
            if (warnings == (int)swFileLoadWarning_e.swFileLoadWarning_ReadOnly)
            {
                MessageBox.Show("This file is read-only.");
                boolstat = false;
            }

            if (tmpObj == null)
            {
                MessageBox.Show("Cannot locate the file.");
                boolstat = false;
            }

            //Re-activate the assembly so that you can add the component to it
            swModel = (ModelDoc2)swApp.ActivateDoc2(AssemblyTitle, true, ref errors);
            swAssy = (AssemblyDoc)swModel;


            // Add the component to the assembly document.
            // Currently only one option,
            // swAddComponentConfigOptions_e.swAddComponentConfigOptions_CurrentSelectedConfig,
            // works for adding a part using AddComponent5

            // The other options,
            // swAddComponentConfigOptions_e.swAddComponentConfigOptions_NewConfigWithAllReferenceModels  
            // and swAddComponentConfigOptions_e.swAddComponentConfigOptions_NewConfigWithAsmStructure,
            // work only for adding assemblies using AddComponent5
            swcomponent = (Component2)swAssy.AddComponent5(strCompModelname, (int)swAddComponentConfigOptions_e.swAddComponentConfigOptions_CurrentSelectedConfig, "", false, "", -1, -1, -1);

            // Get the name of the component for the mate
            strCompName = swcomponent.Name2;

            // Create the name of the mate and the names of the planes to use for the mate
            MateName = "top_coinc_" + strCompName;
            FirstSelection = "Top@" + strCompName + "@" + AssemblyName;
            SecondSelection = "Front@" + AssemblyName;
            swDocExt = (ModelDocExtension)swModel.Extension;
            swModel.ClearSelection2(true);

            // Select the planes for the mate
            boolstat = swDocExt.SelectByID2(FirstSelection, "PLANE", 0, 0, 0, true, 1, null, (int)swSelectOption_e.swSelectOptionDefault);
            boolstat = swDocExt.SelectByID2(SecondSelection, "PLANE", 0, 0, 0, true, 1, null, (int)swSelectOption_e.swSelectOptionDefault);

            // Add the mate
            matefeature = (Feature)swAssy.AddMate3((int)swMateType_e.swMateCOINCIDENT, (int)swMateAlign_e.swMateAlignALIGNED, false, 0, 0, 0, 0, 0, 0, 0,
            0, false, out mateError);
            matefeature.Name = MateName;

            swModel.ViewZoomtofit2();
        }

        public SldWorks swApp;
    }
}