How to display an item from comboBox to a list Box

Question

I am working on a window form application. I have a comboBox and a listBox. In my comboBox, I have 5 items in it and I want to display the according item that I selected from the comboBox to a listBox.

Let say if I select item 1, it will show item 1. If I select item 2, it will show item 2 and item 1 will disappear and vice versa. So far, I have tried this code

listBox1.Items.Add(name)

This ListBox add statment adds the new item to the listBox such as item1, item2, item3 and so on, which is not what I want.

code.

using System.IO;
using System;

class Program
{
    static void Main()
    {
        Console.WriteLine("Hello, World!");

           private void loadComboBox()
        {
            myConn = new SqlConnection("Server = localhost; Initial Catalog= dbName; Trusted_Connection = True");

            try
            {
                myConn.Open();
                string query = "select * from Application_Detail";

                myCommand = new SqlCommand(query, myConn);

                //myCommand.ExecuteNonQuery();
                //reading the value from the query
                SqlDataReader dr = myCommand.ExecuteReader();
                //Reading all the value one by one
                while (dr.Read())
                {
                    //column is 1 in Application_Detail Data
                    string name = dr.GetString(1);
                    applicationComboBox.Items.Add(name);
                }
                myConn.Close();
            }catch(Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }

        private void fill_checkListBox()
        {
            myConn = new SqlConnection("Server = localhost; Initial Catalog= dbName; Trusted_Connection = True");

            try
            {
                myConn.Open();

                int index = applicationComboBox.SelectedIndex + 1;
                string query = " SELECT td.chineseName, ad.applicationId, aud.applicationId, ad.applicationName FROM[AppUser_Detail] as aud LEFT OUTER JOIN[Teacher_Detail] as td ON aud.teacherId = td.teacherId LEFT OUTER JOIN[Application_Detail] as ad ON aud.applicationId = ad.applicationId LEFT OUTER JOIN[Class_Detail] as cd ON aud.classId = cd.classId where aud.applicationId = '" + index + "' AND NOT(td.teacherId IS NULL AND cd.classId IS NULL)";
                myCommand = new SqlCommand(query, myConn);

                SqlDataReader dr = myCommand.ExecuteReader();

                //Reading all the value one by one
                while (dr.Read())
                {
                    //column is 1 in Application_Detail Data



                        //string value = applicationComboBox.GetItemText(applicationComboBox.Items[i]);
                        string name = dr.GetString(0);

teacherCheckListBox.Items.Clear();\ updated this line teacherCheckListBox.Items.Add(name);

                }
                //teacherCheckListBox.DataSource = dt;
                myConn.Close();
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }
    }
}

Any Ideas?

Do you want your list box to show only one item at a time, which was selected from combobox? and combobox will have 4 items max, as 1 will be moved to listbox? — Amnesh Goel
Yeah something like that. You know that most of the comboBox in the pc? It only show the item what you selected from the comboBox. — RedRocket

Sajeetharan Sajeetharan · Accepted Answer · 2015-09-19T04:18:10

   public Form1()
        {
            InitializeComponent();
            List<string> items = new List<string>();
            items.Add("sachin");
            items.Add("dravid");
            items.Add("ganguly");
            cmbSample.DataSource = items;
        }

        private void cmbSample_SelectedValueChanged(object sender, EventArgs e)
        {
            lstSample.Items.Clear();
            lstSample.Items.Add(cmbSample.SelectedItem);
            lstSample.SelectedItem = cmbSample.SelectedItem;
        }

How to display an item from comboBox to a list Box

2 Answers