how to use variable in user control from form

Question

I have a list in a form and I want to access this list from Form1 in user control.

The following code line would be in Form1 :

public partial class form : Form
{
    public static List<daftarBarang> tambahBarang = new List<daftarBarang>();
}

//UserControl
parent.tambahBarang.Add(new daftarBarang(nama, harga, stok, parent.tambahBarang.Count));

The issue is I cannot use my list, if I don't use static then the list won't save the results.

Answer 1

I don't understand exactly how you wired up your Form and UserControl but here's an example of a UserControl that works as a container which displays the items that you add via AddItem .

If this example does not help you to solve your problem please provide us with more information so that we can assist you further.

using System;
using System.ComponentModel;
using System.Windows.Forms;

namespace WindowsFormsApp
{
    public class DaftarBarang
    {
        public string Nama { get; set; }
        public int Harga { get; set; }
    }

    public class TheUserControl : UserControl
    {
        private readonly BindingList<DaftarBarang> list = new BindingList<DaftarBarang>();

        public TheUserControl()
        {
            var grid = new DataGridView
            {
                DataSource = new BindingSource(list, null)
            };

            AutoSize = true;
            Controls.Add(grid);
        }

        public void AddItem(DaftarBarang barang)
        {
            list.Add(barang);
        }
    }

    public class TheForm : Form
    {       
        public TheForm()
        {
            var uc = new TheUserControl();
            uc.AddItem(new DaftarBarang { Nama = "Sepatu olahraga", Harga = 255000 });
            uc.AddItem(new DaftarBarang { Nama = "Baju cantik", Harga = 85000 });

            Controls.Add(uc);
         }
    }

    static class Program
    {
        [STAThread]
        static void Main()
        {
            Application.Run(new TheForm());
        }
    }
}