Dictionary icindeki anahtari listboxa yazdirmak

Question

		int index = 1;
                string filePath = dir + "Settings.json";
                

                var setting = new JsonSerializerSettings();
                setting.Formatting = Formatting.Indented;
                setting.ReferenceLoopHandling = ReferenceLoopHandling.Ignore;
                setting.NullValueHandling = NullValueHandling.Ignore;

              if (!File.Exists(filePath))
              {
                var myFile = File.Create(filePath);
                myFile.Close();
              }
            // Read existing json data
                string jsonData = System.IO.File.ReadAllText(filePath);
                // Deserialize to object or create new list
               
                linechart.MaxDatapoint = Int32.Parse(MaxDPtxt_line.Text);
                linechart.ChartDataMarkerShowlabel = Helper.SelectedMarker(cmbDMarker_line.SelectedItem.ToString());
                linechart.ChartBackgroundColor = Helper.SelectedColor(cmbBGColor_line.SelectedItem.ToString());
                linechart.ChartTitleColor = Helper.SelectedColor(cmbTColor_line.SelectedItem.ToString());
                linechart.ChartTitle = Titletxt_line.Text;
                linechart.Type = Typtxt_line.Text;
                linechart.ValueRange = Int32.Parse(valueRangetxt_line.Text);


                var list = JsonConvert.DeserializeObject<Dictionary<string, LineChart>>(jsonData)
                              ?? new Dictionary<string, LineChart>();
                
                Dictionary<string, LineChart> points = new Dictionary<string, LineChart>();
                while (list.ContainsKey("Linechart " + index.ToString()))
                {
                index++;
                }
                if (!list.ContainsKey("Linechart " + index.ToString()))
                {
                points.Add("Linechart " + index.ToString(), linechart);
                foreach (var newpoints in points)
                list.Add(newpoints.Key, newpoints.Value);
                }
                jsonData = JsonConvert.SerializeObject(list, setting);
                System.IO.File.WriteAllText(filePath, jsonData);

Merhabalar , yukaridaki kodla textboxa verilen degerleri json olarak kaydediyorum.Kaydederken bir grafik tipinden birden fazla varsa linechart1, linechart2 ... seklinde kaydediyorum.

Kaydettigim bu grafik adlarini  (yeniden düzenlemek icin) form yüklendiginde listboxa yüklemek istiyorum.

Linechart 1

Linechart2

Barchart1   seklinde.

bunu nasil yapabilirim , yardim ederseniz sevinirim.

Allah razi olsun simdiden