Datagrid binding to ArrayList: How to add items (Compact Framework)

namespace DeviceApplication1
{
    public partial class Form1 : Form
    {
        private ArrayList Items;
 
        public Form1()
        {
            InitializeComponent();
            AddItems();
        }
 
        private void AddItems()
        {
            Items = new ArrayList();
 
            Items.Add(new item("AA-123", "Camera #1", 145));
            Items.Add(new item("AA-527", "Camera #2", 156.76));
            BindDataGridToArrayList();
        }
 
        private void BindDataGridToArrayList()
        {
            dataGrid1.DataSource = Items;
 
            DataGridTableStyle ts = new DataGridTableStyle();
            ts.MappingName = "ArrayList";
 
            DataGridTextBoxColumn cs1 = new DataGridTextBoxColumn();
            cs1.MappingName = "ItemID";
            cs1.HeaderText = "Item ID";
            ts.GridColumnStyles.Add(cs1);
 
            DataGridTextBoxColumn cs2 = new DataGridTextBoxColumn();
            cs2.MappingName = "Description";
            cs2.HeaderText = "Description";
            ts.GridColumnStyles.Add(cs2);
 
            DataGridTextBoxColumn cs3 = new DataGridTextBoxColumn();
            cs3.MappingName = "Cost";
            cs3.HeaderText = "Cost";
            ts.GridColumnStyles.Add(cs3);
 
            dataGrid1.TableStyles.Clear();
            dataGrid1.TableStyles.Add(ts);
        }
 
        private void button1_Click(object sender, EventArgs e)
        {
            Items.Add(new item("AA-909", "Camera #3", 500.67));
            CurrencyManager cm = (CurrencyManager)this.dataGrid1.BindingContext[Items];
            
            if (cm != null)
                cm.Refresh();
        }
 
        public struct item
        {
            private string itemID_;
            private string description_;
            private double cost_;
 
            public item(string ItemID, string Description, double Cost)
            {
                itemID_ = ItemID;
                description_ = Description;
                cost_ = Cost;
            }
            public string ItemID
            {
                get { return itemID_; }
                set { itemID_ = value; }
            }
            public string Description
            {
                get { return description_; }
                set { description_ = value; }
            }
            public double Cost
            {
                get { return cost_; }
                set { cost_ = Math.Round(value, 2); }
            }
        }
    }
}

                                  

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