How to refresh DataSource of a ListBox

Question

Form has one Combobox and one ListBox. When the \"Add\" button is clicked, I want to add the selected item from the ComboBox to the ListBox.

public partial c         


        

Answer 1

Call ShowData() when the form initializes to populate your listbox on initialization

 public Department()
        {
            InitializeComponent();
            ShowData();
        }

ShowData() Method, where BindingSource, DisplayMember and ValueMember are set

private void ShowData()
            {
                using (var uow = new UnitOfWork(new SellContext()))
                {
                    listBox1.DataSource = uow.Departments.GetAll().ToList();
                    listBox1.DisplayMember = "DepartmentName";
                    listBox1.ValueMember = "DepartmentId"; 
                    //listBox1.Invalidate();       
                }
            }

In the implementation below when a department is deleted from database the listbox refreshes with the current collection

private void button1_Click(object sender, EventArgs e)
    {
        try {
            using (var uow = new UnitOfWork(new SellContext()))
            {
                int count = uow.Departments.FindDepartmentByName(txtDeptName.Text.ToString());
                if (count>0)
                {
                    MessageBox.Show("This Department Already Exists", "SellRight", MessageBoxButtons.OK, MessageBoxIcon.Hand);
                }

                else
                {
                    department dept = new department();
                    dept.DepartmentName = txtDeptName.Text.ToString();
                    uow.Departments.Create(dept);
                    if (uow.Complete() > 0)
                    {           
                        MessageBox.Show("New Department Created", "SellRight", MessageBoxButtons.OK, MessageBoxIcon.Information);
                        txtDeptName.Text = "";
                        ShowData();      
                    }
                    else
                    {
                        MessageBox.Show("Unable to add Department", "SellRight", MessageBoxButtons.OK, MessageBoxIcon.Error);
                        txtDeptName.Text = "";
                        ShowData();
                    }
                }
            }                              
        }
        catch(Exception ex)
        {
            ex.ToString();
        }
    }