using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace ComboBox_Data_Add_Remove
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        // Button1: Add item to ComboBox1
        private void button1_Click(object sender, EventArgs e)
        {  
            comboBox1.Items.Add(textBox1.Text);
        }

        // Button2: Remove item from ComboBox1
        private void button2_Click(object sender, EventArgs e)
        {  
            comboBox1.Items.Remove(textBox1.Text);
        }

        // Button3: Remove item from ComboBox2
        private void button3_Click(object sender, EventArgs e)
        {  
            comboBox2.Items.Remove(textBox2.Text);
        }

        // Button4: Add item to ComboBox2
        private void button4_Click(object sender, EventArgs e)
        {  
            comboBox2.Items.Add(textBox2.Text);
        }

        // Button5: Move selected item from ComboBox1 to ComboBox2
        private void button5_Click(object sender, EventArgs e)
        {  
            comboBox2.Items.Add(comboBox1.Text);
            comboBox1.Items.Remove(comboBox1.Text);
        }

        // Button6: Move selected item from ComboBox2 to ComboBox1
        private void button6_Click(object sender, EventArgs e)
        {  
            comboBox1.Items.Add(comboBox2.Text);
            comboBox2.Items.Remove(comboBox2.Text);
        }

        // Button7: Move all items from ComboBox1 to ComboBox2
        private void button7_Click(object sender, EventArgs e)
        {  
            for (int k = 0; k < comboBox1.Items.Count; k++)
            {
                comboBox2.Items.Add(comboBox1.Items[k]);
            }
            comboBox1.Items.Clear();
        }

        // Button8: Move all items from ComboBox2 to ComboBox1
        private void button8_Click(object sender, EventArgs e)
        {  
            for (int k = 0; k < comboBox2.Items.Count; k++)
            {
                comboBox1.Items.Add(comboBox2.Items[k]);
            }
            comboBox2.Items.Clear();
        }
    }
}