C#, read data from an AutoCAD variable and pass it to another AutoCAD variable.

[dilan]

Hi, I'm writing a function in C#. The goal is to read an XML file and extract all point numbers into a list. I can't figure out how to pass the file path for reading through an AutoCAD variable. Right now, I'm doing it via a configuration file, but that's not convenient. I want to get the file path from an AutoCAD variable—for example, my file path is stored in a variable like filepathXML.

Additionally, the function currently outputs the result to the AutoCAD command line, but I need to assign this result to an AutoCAD variable (e.g., listPointID). I also can't understand how to do that.

Overall, the code works and does what I need, but I'm struggling with handling the variables properly.

 

using System;
using System.Collections.Generic;
using System.IO;
using System.Reflection;
using System.Text;
using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.Runtime;
using Autodesk.AutoCAD.EditorInput;

public class PointIdExtractor
{
    [CommandMethod("GetPointIds")]
    public static void GetPointIdsCommand()
    {
        Document doc = Application.DocumentManager.MdiActiveDocument;
        Editor ed = doc.Editor;

        try
        {
            // Getting the path from the configuration file
            string filePath = GetFilePathFromConfig();

            if (string.IsNullOrEmpty(filePath))
            {
                ed.WriteMessage("\nError: Failed to get file path from configuration");
                return;
            }

            if (!File.Exists(filePath))
            {
                ed.WriteMessage($"\nError: File not found at path: {filePath}");
                return;
            }

            List<int> ids = GetPointIdsFromFile(filePath);

            // We format the output as (1 2 3 4 5 ...)
            ed.WriteMessage($"\nFound point IDs: {FormatAsLispList(ids)}");
        }
        catch (System.Exception ex)
        {
            ed.WriteMessage($"\nError: {ex.Message}");
        }
    }

    private static string GetFilePathFromConfig()
    {
        try
        {
            // Path to configuration file next to DLL
            string configPath = Path.Combine(
                Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location),
                "PointExtractor.cfg");

            if (!File.Exists(configPath))
            {
                // Create a file with an example if it does not exist
                File.WriteAllText(configPath, "DataXmlPath=C:\\path\\to\\your\\file.xml");
                return null;
            }

            // Read all configuration lines
            foreach (string line in File.ReadAllLines(configPath))
            {
                if (line.StartsWith("DataXmlPath="))
                {
                    return line.Substring("DataXmlPath=".Length).Trim();
                }
            }
            return null;
        }
        catch
        {
            return null;
        }
    }

    private static string FormatAsLispList(List<int> numbers)
    {
        StringBuilder sb = new StringBuilder("(");
        bool first = true;

        foreach (int num in numbers)
        {
            if (!first) sb.Append(" ");
            sb.Append(num);
            first = false;
        }
        sb.Append(")");

        return sb.ToString();
    }

    public static List<int> GetPointIdsFromFile(string filePath)
    {
        List<int> ids = new List<int>();
        const string searchPattern = "<P id=\"";

        try
        {
            using (StreamReader reader = new StreamReader(filePath, Encoding.UTF8))
            {
                string line;
                while ((line = reader.ReadLine()) != null)
                {
                    int pos = 0;
                    while ((pos = line.IndexOf(searchPattern, pos, StringComparison.Ordinal)) != -1)
                    {
                        int start = pos + searchPattern.Length;
                        int end = line.IndexOf('"', start);

                        if (end > start)
                        {
                            string numStr = line.Substring(start, end - start);
                            if (int.TryParse(numStr, out int num))
                            {
                                ids.Add(num);
                            }
                        }

                        pos = end > 0 ? end : pos + 1;
                    }
                }
            }
            return ids;
        }
        catch (System.Exception ex)
        {
            throw new System.Exception($"Failed to process file {filePath}: {ex.Message}");
        }
    }
}

 

[Danielm103]

Are you trying to pass this list back to autolisp?