随机选择

以下是效果

以下是设计

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

namespace 抽奖
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        
        private void timer1_Tick(object sender, EventArgs e)//选择listbox.intem
        {
            Random rnd = new Random();
            listBox1.SelectedIndex = rnd.Next(0, listBox1.Items.Count);
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            string[] mystr = File.ReadAllLines(System.Environment.CurrentDirectory + "\\成员.txt", Encoding.Default);
            foreach (string x in mystr)
            {
                listBox1.Items.Add(x);
            }
        }

        private void button1_Click(object sender, EventArgs e)
        {
            timer1.Enabled = true;
        }

        private void button2_Click(object sender, EventArgs e)
        {
            timer1.Enabled = false;
            label1.Text = listBox1.SelectedItem.ToString();           
        }
    }
}