New Post: MapLineLayer Not Displaying

I am attempting to add a MapLineLayer with lines to my map.
What I am trying to do is:

• Create a new MapLineLayer
• Add line (features) to the layer
• Add a "Volume" attribute to the attribute table with a value corresponding to each line
• Create a new LineScheme containing LineCategories for each unique "Volume" value
• The "Volume" data comes from an OD_matrix (2D array)
• Line coordinates come from two arrays x[], y[]

---

MapLineLayer LineLyr = new MapLineLayer;
LineLyr.DataSet = new FeatureSet(FeatureType.Line);
LineLyr.DataSet.FillAttributes();
LineLyr.DataSet.DataTable.Columns.Add("Volume");
LineScheme LineSch = new LineScheme();
LineLyr.Symbology = LineSch;

IFeature feature;
LineCategory[] lineCat = new LineCategory[centroid_nodes.Count];

LineString desire_line;
Coordinate from_coord = new Coordinate();
var coord_set = new List<Coordinate>();

 for (i = 0; i < centroid_nodes.Count; i++)
 {
     from_coord = new Coordinate(x_coords[i], y_coords[i]);
     coord_set.Add(from_coord);
     coord_set.Add(to_zone_coord);
     desire_line = new LineString(coord_set);

     feature = LineLyr.DataSet.AddFeature(desire_line);
     coord_set.Clear();

     feature.DataRow.BeginEdit();
     feature.DataRow["Volume"] = (OD_matrix[i][to_zone]).ToString();
     feature.DataRow.EndEdit();

     lineCat[i] = new LineCategory(Color.Blue, (double)(OD_matrix[centroid_nodes[i]][to_zone] * 5));
     lineCat[i].FilterExpression = "[Volume] = " + (OD_matrix[centroid_nodes[i]][to_zone]).ToString();
     lineCat[i].LegendText = (centroid_nodes[i]).ToString();
     LineSch.AddCategory(lineCat[i]);
}

map1.Layers.Add(LineLyr);
LineLyr.DataSet.InitializeVertices();
map1.ResetBuffer();

---

The OD_matrix and coordinate variables are defined elsewhere in the code.

When I run my program, the categories show up correctly in the legend, however the map control doesn't change.

Any help appreciated!

Sorry if anything is unclear or I have made any stupid mistakes; I am still new to this.