The thread of C # is random

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;using system.threading;namespace windowsformsapplication2{public partial class Form1:form {public Form1 () {Initializeco        Mponent ();  private void Form1_Load (object sender, EventArgs e) {control.checkforillegalcrossthreadcalls =        False        } bool A;            public void PlayGame () {Random rd = new Random (); while (a) {this.label1.Text = Rd. Next (0, 10).                ToString (); This.label2.Text = Rd. Next (0, 10).                ToString (); This.label3.Text = Rd. Next (0, 10).            ToString (); }} private void Button1_Click (object sender, EventArgs e) {if (!                a) {a=true; This.button1.Text = "pause";                Thread th = new Thread (playGame); Th.                IsBackground = true; Th.            Start ();                } else {this.button1.Text = "start";            A = false; }        }    }}

　　

The thread of C # is random