Unwanted labels appear on RangeBar chart AxisX when adding data

Question

I have a Chart (RangeBarChart) with a ChartArea attached to it. The ChartArea has one Series attached to it. I also have a List<string> , this stringlist is filled with the values I want the Axislabels on my AxisX to have. In my example screenshot, this stringlist contains 6 strings.

All the 6 labels are named correct, but at the upper and lower limits of my AxisX, the labels are numbered as well, see screenshot (upper part, '-1' and the '6' labels are undesired).

Screenshot link: https://imgur.com/a/pwYF4yl

I add data to my chart with two lines of code in a foreach loop. I found that when I comment out these two lines, the extra numbers on my axis don't appear, but obviously this is a non-solution, as I'm also not showing any data. I also can't delete the labels manually in code because I have no pointIndices pointing to them. When looking at my series.Points[] collection in the debugger, all their X-values are between 0 and 5 (also in screenshot).

How can I get rid of these labels?

I recreated the unwanted behaviour in a quick test project, just add a Chart called 'chart' in the designer and copy this code in the code part of your main form and you can recreate the problem for yourself.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Windows.Forms.DataVisualization.Charting;

namespace XAxisLabelsNumbersTest
{
    public partial class Form1 : Form
    {
        ChartArea ca;
        Series serie;
        List<string> xLabels = new List<string> {"Label1", "Label2", "Label3", "Label4", "Label5", "Label6"};
        List<myObj> myObjList = new List<myObj>();

        public class myObj
        {
            public Int32 begin { get; set; }
            public Int32 end { get; set; }
            public int xcord { get; set; }
            public int pointIndex { get; set; }
            public string label { get; set; }

            public myObj(Int32 begin, Int32 end, string label)
            {
                this.begin = begin;
                this.end = end;
                this.label = label;
            }
        }

        public Form1()
        {
            InitializeComponent();
            // Setting some properties regarding chart behaviour
            ca = chart.ChartAreas.Add("ca");
            serie = chart.Series.Add("serie");
            serie.ChartArea = ca.Name;
            serie.ChartType = SeriesChartType.RangeBar;
            serie.XValueType = ChartValueType.String;
            serie.YValueType = ChartValueType.Int32;
            serie["PixelPointWidth"] = "10";
            //ca.AxisY.LabelStyle.Format = "HH:mm tt";
            ca.AxisX.MajorGrid.Interval = 1;

            ca.AxisY.Minimum = 0;
            ca.AxisY.Maximum = 6;

            Title title = new Title("Title");
            chart.Titles.Add(title);
            title.DockedToChartArea = ca.Name;
            title.IsDockedInsideChartArea = false;
            title.Font = new Font("Serif", 18);
            ca.AxisX.LabelAutoFitStyle = LabelAutoFitStyles.None;
            ca.AxisX.LabelStyle.Font = new Font("Trebuchet MS", ca.AxisX.LabelAutoFitMaxFontSize, FontStyle.Bold);
            ca.AxisX.LabelStyle.Interval = 1;

            // Create Labels from xLabels
            for (int i = 0; i < xLabels.Count; i++)
            {
                int pi = serie.Points.AddXY(i, null, null);
                serie.Points[pi].AxisLabel = xLabels[i];
            }

            // Fill myObjList with testdata
            myObjList.Add(new myObj(0, 1, "Label1"));
            myObjList.Add(new myObj(1, 2, "Label2"));
            myObjList.Add(new myObj(2, 3, "Label3"));
            myObjList.Add(new myObj(3, 4, "Label4"));
            myObjList.Add(new myObj(4, 5, "Label5"));
            myObjList.Add(new myObj(5, 6, "Label6"));

            // Fill serie with data from myObjList
            // Comment out this foreach block and the weird label numbering is gone...
            foreach (myObj myObj in myObjList) 
            {
                myObj.xcord = xLabels.FindIndex(Label => Label.Equals(myObj.label));
                myObj.pointIndex = serie.Points.AddXY(myObj.xcord, myObj.begin, myObj.end);
            }
        }
    }
}

Answer 1

You can hide both 'endlabels' by setting this axis property: Axis.LabelStyle.IsEndLabelVisible :

ca.Axis.LabelStyle.IsEndLabelVisible = false;