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;using System.Collections;namespace MoveItem{  public partial class Form1 : Form  {    public Form1()    {      InitializeComponent();    }    ArrayList list = new ArrayList();    private void listBox1_SelectedIndexChanged(object sender, EventArgs e)    {    }    private void Form1_Load(object sender, EventArgs e)    {      for (int i = 1; i <= 10; i++)      {        list.Add(i);        string s = i.ToString();        listBox1.Items.Add(s);      }    }    private void listBox2_SelectedIndexChanged(object sender, EventArgs e)    {          }    private void button1_Click(object sender, EventArgs e)    {      //單選，無法實現多選      //string str = this.listBox1.Text.Trim().ToString();      //if (listBox1.Items.Contains(str))      //{      //  listBox1.Items.Remove(str);      //  listBox2.Items.Add(str);      //}      for (int i=0;i<listBox1.SelectedIndices.Count;i++)      {        listBox2.Items.Add(listBox1.Items[listBox1.SelectedIndices[i]]);        listBox1.Items.RemoveAt(listBox1.SelectedIndices[i]);        i--;      }    }    private void button2_Click(object sender, EventArgs e)    {      for (int i = 0; i < listBox2.SelectedIndices.Count; i++)      {        listBox1.Items.Add(listBox2.Items[listBox2.SelectedIndices[i]]);        listBox2.Items.RemoveAt(listBox2.SelectedIndices[i]);        i--;      }    }    private void button3_Click(object sender, EventArgs e)    {      listBox2.Items.AddRange(listBox1.Items);      listBox1.Items.Clear();    }    private void button4_Click(object sender, EventArgs e)    {      listBox1.Items.AddRange(listBox2.Items);      listBox2.Items.Clear();    }  }}