public partial class MainWindow : Window
        {
            public ObservableCollection<ComboboxData> Cmb { get; set; }
            public ObservableCollection<MyData> MyDatas { get; set; }
            public MainWindow()
            {
                InitializeComponent();
    
                Cmb = new ObservableCollection<ComboboxData>();
                MyDatas = new ObservableCollection<MyData>();
    
                MyDatas.Add(new MyData("Name1", 1, Cmb));
                MyDatas.Add(new MyData("Name2", 2, Cmb));
                MyDatas.Add(new MyData("Name3", 3, Cmb));
    
                Cmb.Add(new ComboboxData("2", "Exclamation", "!"));
                Cmb.Add(new ComboboxData("3", "Ampersat", "@"));
                Cmb.Add(new ComboboxData("4", "Ampersand", "&"));
                DataContext = this;
            }
        }
        public class MyData
        {
            public string Name { get; set; }
            public int Num { get; set; }
            public ObservableCollection<ComboboxData> ComboboxDatas { get; set; }
            public MyData() { }
            public MyData(string name, int num, ObservableCollection<ComboboxData> comboboxes)
            {
                this.Name = name;
                this.Num = num;
                this.ComboboxDatas = comboboxes;
            }
        }
        public class ComboboxData
        {
            public string Index { get; set; }
            public string Name { get; set; }
            public string Symbol { get; set; }
            public ComboboxData() { }
            public ComboboxData(string index, string name, string symbol)
            {
                this.Index = index;
                this.Name = name;
                this.Symbol = symbol;
            }
        }