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

namespace MyLittleGame
{
    public partial class Form1 : Form
    {
        //定义全局变量
        Label label;
        Thread myThread;
        //构造方法
        public Form1()
        {
            InitializeComponent();
        }

        //label下落方法
        public void _falling()
        {
            CheckForIllegalCrossThreadCalls = false;

            while (this.label.Top <= this.panel1.Height)
            {
                this.label.Top += 1;
                Thread.Sleep(5);
            }
            this.label.Dispose();
            myThread.Abort();
        }

        //每间隔一定时间发生
        private void timer1_Tick(object sender, EventArgs e)
        {
            label = new Label();
            label.Height = 10;
            label.Width = 50;
            label.Left = new Random().Next(9) * 50;
            switch(new Random().Next(3)+new Random().Next(2)+1){
            case 1:label.BackColor = Color.RoyalBlue;break;
            case 2:label.BackColor = Color.PowderBlue;break;
            case 3:label.BackColor = Color.BlueViolet;break;
            default: label.BackColor = Color.MediumVioletRed; break;
            }
            panel1.Controls.Add(label);
            myThread = new Thread(new ThreadStart(_falling));
            myThread.Start();
        }

        //start按钮事件
        private void startToolStripMenuItem_Click(object sender, EventArgs e)
        {
            timer1.Start();
        }
    }
}