Issue passing <List> object to multidimensional array

Question

Issue trying to pass coordinates in to a multidimensional array. Errors thrown:

(1) at var newArray = item.To2dArray(); in GetInstructions() method:

List does not contain a definition for To2dArray and no extensible method To2dArray accepting a first argument of type ist

(2) at public partial class SiteMaster : MasterPage when the method public static Coords[,] To2dArray(this List<List<Coords>> list) is added

Extension method must be defined in non-generic static class

My list structure

    public class Route
    {
        public string status_message { get; set; }
        public string route_geometry { get; set; }
        public int status { get; set; }
        //route_instructions is what I'm interested in
        public List<List<object>> route_instructions { get; set; }
    }

    public class Coords
    {
        public int Lat { get; set; }
        public int Lon { get; set; }
        public Coords(string a, string b)
        {
            this.Lat = Convert.ToInt32(a);
            this.Lon = Convert.ToInt32(b);
        }
    }
    List<Coords> Coordinates = new List<Coords>();

Code to deserialise JSON

    private void GetInstructions()
    {
            string strurltest = String.Format("https://developers.onemap.sg/privateapi/routingsvc/route?start="+
                        startLat+","+ startLon +"&end="+ destinationLat +","+ destinationLon+"&"+
                        "routeType="+ transportType + "&token="+token);
            WebRequest requestObjGet = WebRequest.Create(strurltest);
            requestObjGet.Method = "GET";
            HttpWebResponse responseObjGet = null;
            responseObjGet = (HttpWebResponse)requestObjGet.GetResponse();
            string strresulttest = null;
            using (Stream stream = responseObjGet.GetResponseStream())
            {
                StreamReader sr = new StreamReader(stream);
                strresulttest = sr.ReadToEnd();
                sr.Close();
            }

            Route route = new JavaScriptSerializer().Deserialize<Route>(strresulttest);
            route_geometry = route.route_geometry;
            //display route instructions

            foreach (var item in route.route_instructions)
            {
                var newArray = item.To2dArray();
                System.Diagnostics.Debug.WriteLine(item[3]);
                TextBox3.Text = TextBox3.Text + Environment.NewLine + item[9];
            }

        }

Code to convert list object to multidimensional array

public static Coords[,] To2dArray(this List<List<Coords>> list)
    {
        if (list.Count == 0 || list[0].Count == 0)
            throw new ArgumentException("The list must have non-zero dimensions.");

        var result = new Coords[list.Count, list[0].Count];
        for (int i = 0; i < list.Count; i++)
        {
            for (int j = 0; j < list[i].Count; j++)
            {
                if (list[i].Count != list[0].Count)
                    throw new InvalidOperationException("The list cannot contain elements (lists) of different sizes.");
                result[i, j] = list[i][j];
            }
        }

        return result;
    }

List object when printed is in this format: (when System.Diagnostics.Debug.WriteLine(item[3]); in GetInstructions()

1.315396,103.764419
1.314333,103.763455
1.312906,103.766496
1.312109,103.772234

have you stepped through this to identify the problem ?

TheGeneral
– TheGeneral

2019-10-28 06:30:40 +00:00
Commented Oct 28, 2019 at 6:30 — TheGeneral
– TheGeneral, Commented Oct 28, 2019 at 6:30

pocki_c · Accepted Answer · 2019-10-28 06:40:51Z

1

You can only use a Method as Extension, if it is static and in an static class. Your method To2dArray must be moved to an extra static class. This is what the following message means:

Extension method must be defined in non-generic static class

The other problem is, that the signature of the method does not fit: You are iterating through route.route_instructions so item is of type List<object> but your method needs List<List<Coords>>

foreach (var item in route.route_instructions)
{
      var newArray = item.To2dArray();
///...

edited Oct 28, 2019 at 6:40

answered Oct 28, 2019 at 6:35

pocki_c

1843 silver badges7 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Issue passing <List> object to multidimensional array

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related