震动问题

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 shake_shake
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }        private void btnsend_Click(object sender, EventArgs e)
        {
            txtget.Text = txtsend.Text + System.Environment.NewLine +System.DateTime.Now.Day;
            txtsend.Clear();
        }        private void btnshake_Click(object sender, EventArgs e)
        {
            int recordx = this.Left;
            int recordy = this.Top;
            Random raline = new Random();
            for (int i = 0; i < 1000; i++)
            {
                int x = raline.Next(recordx);//别人说这里是rand。不懂什么意思
                int y = raline.Next(recordy);
                if (x % 2 == 0)
                { 
                    this.Left=this.Left + x;
                }
                else
                {
                    this.Left = this.Left - x ;
                }
                if (y % 2 == 0)
                {
                    this.Top = this.Top +y;
                }
                else
                {
                    this.Top = this.Top - y;
                }
                //System.Threading.Thread.Sleep(1);//不知道这句什么意思
            }
            this.Left = recordx;
            this.Top = recordy;        }
        
    }
}//问题1：为什么震动的时候，窗体在屏幕中不停乱跑，不像qq震动一样呢？问题2：int x = raline.Next(recordx);//别人说这里是rand。不懂什么意思/。问题3：System.Threading.Thread.Sleep(1);//不知道这句什么意思