在C#中实现两个listbox的项移动（winform）

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

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

        }

        private void button1_Click(object sender, EventArgs e)
        {
            if (listBox1.Items.Count == 0)
                return;
            if (listBox1.SelectedItem == null)
                return;
            listBox2.Items.Add(listBox1.SelectedItem);
            listBox1.Items.Remove(listBox1.SelectedItem);
            

        }

        private void button2_Click(object sender, EventArgs e)
        {
            if (listBox1.Items.Count == 0)
                return;
            for(int i=0;i<listBox1.Items.Count;i++)
            {
               listBox2.Items.Add(listBox1.Items[i]);
            }

            for (int j = 0; j< listBox2.Items.Count;j++)
            {
                listBox1.Items.Remove(listBox2.Items[j]);
            }

        }

        private void button3_Click(object sender, EventArgs e)
        {
            if (listBox2.Items.Count == 0)
                return;
            if (listBox2.SelectedItem == null)
                return;
            listBox1.Items.Add(listBox2.SelectedItem);
            listBox2.Items.Remove(listBox2.SelectedItem);

        }

        private void button4_Click(object sender, EventArgs e)
        {
            if (listBox2.Items.Count == 0)
                return;
            for (int i = 0; i < listBox2.Items.Count; i++)
            {
                listBox1.Items.Add(listBox2.Items[i]);
            }

            for (int j = 0; j < listBox1.Items.Count; j++)
            {
                listBox2.Items.Remove(listBox1.Items[j]);
            }

        }
    }
}