C#（二十九）之C#listBox checkedlistbox imagelist

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 _0416Day
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        private void putButton_Click(object sender, EventArgs e)
        {
            int index = listBox1.SelectedIndex;
            if(index == 0)
            {
                result.Text = listBox1.SelectedItem.ToString();
            }
            else if(index == 1)
            {
                result.Text = listBox1.SelectedItem.ToString();
            }
            else if (index == 2)
            {
                result.Text = listBox1.SelectedItem.ToString();
            }
            else
            {
                MessageBox.Show("请选择选项");
            }
        }
        /**
         * 添加按钮
         */
        private void Add_Click(object sender, EventArgs e)
        {
            listBox1.Items.Add(Input.Text);
            Input.Clear();
        }
        /**
         * 移除按钮
         */
        private void Remove_Click(object sender, EventArgs e)
        {
            int sel = listBox1.SelectedIndex;
            if (sel != -1)
            {
                listBox1.Items.RemoveAt(listBox1.SelectedIndex);
            }
            else
            {
                MessageBox.Show("请选择需要移除的选项");
            }
        }
        /**
         * 清空按钮
         */
        private void Clear_Click(object sender, EventArgs e)
        {
            listBox1.Items.Clear();
        }
        /**
         * 复选框默认事件
         * 选中文字打勾才会执行（在不修改CheckOnClick属性时需要双击才会打勾）
         */
        private void fubox_SelectedIndexChanged(object sender, EventArgs e)
        {
        }
        /**
         * 复选框默认事件
         * 选中文字（不打勾）就会执行
         */
        private void fubox_ItemCheck(object sender, ItemCheckEventArgs e)
        {
            // e是参数对象，等于被选中的那个值
            if (e.NewValue == CheckState.Checked)
            {
                // 选中的主键（选中之后显示图片）
                switch (e.Index)
                {
                    case 0: pictureBox1.Image = imageList1.Images[0]; break;
                    case 1: pictureBox2.Image = imageList1.Images[1]; break;
                    case 2: pictureBox3.Image = imageList1.Images[2]; break;
                    case 3: pictureBox4.Image = imageList1.Images[3]; break;
                }
            }
            else
            {
                // 未选中的主键（去掉选中之后图片消失）
                switch (e.Index)
                {
                    case 0: pictureBox1.Image = null; break;
                    case 1: pictureBox2.Image = null; break;
                    case 2: pictureBox3.Image = null; break;
                    case 3: pictureBox4.Image = null; break;
                }
            }
        }
    }
}