using System;using System.Drawing;using System.Collections;using System.ComponentModel;using System.Windows.Forms;using System.Data;using System.Threading;namespace SuspendAndResume{ public class Form1 : System.Windows.Forms.Form { private System.Windows.Forms.Label label1; private System.Windows.Forms.ListBox listBox1; private System.Windows.Forms.Button button1; private System.Windows.Forms.Button button2; private System.Windows.Forms.Button button3; private System.Windows.Forms.Button button4; private System.Windows.Forms.Label label2; private System.Windows.Forms.Timer timer1; private System.ComponentModel.IContainer components; //公共委托，用于輸出素數 public delegate void UD(string returnVal); //聲明私有線程 private Thread pNT; //用于標識是否掛起線程 bool suspend = false; //用于標識線程時候開始運行 bool pNTstart = false; public Form1() {  InitializeComponent();  // TODO: 在 InitializeComponent 調用后添加任何構造函數代碼 } protected override void Dispose( bool disposing ) {  if( disposing )  {  if (components != null)  {   components.Dispose();  }  }  base.Dispose( disposing ); } #region Windows 窗體設計器生成的代碼 private void InitializeComponent() {  this.components = new System.ComponentModel.Container();  this.label1 = new System.Windows.Forms.Label();  this.listBox1 = new System.Windows.Forms.ListBox();  this.button1 = new System.Windows.Forms.Button();  this.button2 = new System.Windows.Forms.Button();  this.button3 = new System.Windows.Forms.Button();  this.button4 = new System.Windows.Forms.Button();  this.label2 = new System.Windows.Forms.Label();  this.timer1 = new System.Windows.Forms.Timer(this.components);  this.SuspendLayout();  // label1  this.label1.Location = new System.Drawing.Point(8, 8);  this.label1.Name = "label1";  this.label1.TabIndex = 0;  this.label1.Text = "已找到的素數：";  // listBox1  this.listBox1.ItemHeight = 12;  this.listBox1.Location = new System.Drawing.Point(8, 32);  this.listBox1.MultiColumn = true;  this.listBox1.Name = "listBox1";  this.listBox1.Size = new System.Drawing.Size(272, 136);  this.listBox1.TabIndex = 1;  // button1  this.button1.Location = new System.Drawing.Point(19, 184);  this.button1.Name = "button1";  this.button1.Size = new System.Drawing.Size(48, 23);  this.button1.TabIndex = 2;  this.button1.Text = "創建";  this.button1.Click += new System.EventHandler(this.button1_Click);  //  // button2  //  this.button2.Location = new System.Drawing.Point(88, 184);  this.button2.Name = "button2";  this.button2.Size = new System.Drawing.Size(48, 23);  this.button2.TabIndex = 3;  this.button2.Text = "掛起";  this.button2.Click += new System.EventHandler(this.button2_Click);  //  // button3  //  this.button3.Location = new System.Drawing.Point(157, 184);  this.button3.Name = "button3";  this.button3.Size = new System.Drawing.Size(48, 23);  this.button3.TabIndex = 4;  this.button3.Text = "恢復";  this.button3.Click += new System.EventHandler(this.button3_Click);  //  // button4  //  this.button4.Location = new System.Drawing.Point(226, 184);  this.button4.Name = "button4";  this.button4.Size = new System.Drawing.Size(48, 23);  this.button4.TabIndex = 5;  this.button4.Text = "銷毀";  this.button4.Click += new System.EventHandler(this.button4_Click);  //  // label2  //  this.label2.Location = new System.Drawing.Point(24, 224);  this.label2.Name = "label2";  this.label2.Size = new System.Drawing.Size(200, 23);  this.label2.TabIndex = 6;  this.label2.Text = "線程未啟動";  //  // timer1  //  this.timer1.Enabled = true;  this.timer1.Tick += new System.EventHandler(this.timer1_Tick);  //  // Form1  //  this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);  this.ClientSize = new System.Drawing.Size(292, 266);  this.Controls.Add(this.label2);  this.Controls.Add(this.button4);  this.Controls.Add(this.button3);  this.Controls.Add(this.button2);  this.Controls.Add(this.button1);  this.Controls.Add(this.listBox1);  this.Controls.Add(this.label1);  this.Name = "Form1";  this.Text = "素數";  this.Load += new System.EventHandler(this.Form1_Load);  this.ResumeLayout(false); } #endregion /// <summary> /// 應用程序的主入口點。 /// </summary> [STAThread] static void Main() {  Application.Run(new Form1()); } private void button1_Click(object sender, System.EventArgs e) {  //創建線程實例，設置屬性  pNT = new Thread(new ThreadStart(GPN));  pNT.Name = "Prime Numbers Exaple";  pNT.Priority = ThreadPriority.BelowNormal;  //設置按鍵，停用開始按鍵，啟用掛起按鍵和銷毀按鍵  button1.Enabled = false;  button2.Enabled = true;  button4.Enabled = true;  //線程開始，并設置標識  pNT.Start();  pNTstart = true; } private void button2_Click(object sender, System.EventArgs e) {  //設置掛起bool變量為真  suspend = true;  //設置按鍵，停用掛起按鍵， 啟用恢復按鍵  button2.Enabled = false;  button3.Enabled = true; } private void button3_Click(object sender, System.EventArgs e) {  //設置掛起bool變量為假  suspend = false;  //當線程當前狀態為掛起時，恢復該線程  if(pNT.ThreadState == System.Threading.ThreadState.Suspended  || pNT.ThreadState == System.Threading.ThreadState.SuspendRequested)  {  try  {   //恢復線程   pNT.Resume();   //設置按鍵，停用恢復按鍵，啟用掛起按鍵   button3.Enabled = false;   button2.Enabled = true;  }  catch(ThreadStateException Ex)  {   MessageBox.Show(Ex.ToString(), "提示");  }  } } private void button4_Click(object sender, System.EventArgs e) {  //設置按鍵，啟用開始按鍵，停用其他按鍵  button1.Enabled = true;  button2.Enabled = false;  button3.Enabled = false;  button4.Enabled = false;  //銷毀線程  pNT.Abort(); } //GPN為GetPrimeNumber的縮寫，用于查找并顯示素數 public void GPN() {  //聲明變量  long Counter;  //素數個數  long NumberNow;  //當前數  long SqrtOfNow;  //輔助數，做數組下標  bool IsPrime = false; //標識是否為素數  //數組，用于存儲已找到素數  long[] PrimeArray = new long[256];  //委托，用于顯示素數，即將其添加到ListBox中  string[] args = new string[] {"2"};  UD UIDel = new UD(UpdateUI);  //初始化，從3開始計算，從第2個素數開始計算  NumberNow = 3;  Counter = 2;  //添加2為素數，放入素數數組并將其顯示  PrimeArray[1] = 2;  this.Invoke(UIDel, args);  //循環，用于找到并輸出256個素數  while(Counter <= 255)  {  IsPrime = true;  //從1到當前數的平方根，窮盡計算是否為素數  for(SqrtOfNow = 1; (PrimeArray[SqrtOfNow]   * PrimeArray[SqrtOfNow] <= NumberNow);   SqrtOfNow++)  {   //若能被已找到的素數整除，則不是素數   if(NumberNow % PrimeArray[SqrtOfNow] == 0)   {   //若不是素數，跳出for循環   IsPrime = false;   break;   }  }  //若為素數，將其添加到ListBox以顯示  if(IsPrime)  {   //將素數存入數組中儲存   PrimeArray[Counter] = NumberNow;   Counter++;   //將素數顯示到ListBox中   args[0] = NumberNow.ToString();   this.Invoke(UIDel,args);   //利用bool變量，控制是否掛起線程   if( suspend == true)   {   //調用Suspend方法，并捕捉異常   try   {    pNT.Suspend();   }   catch(ThreadStateException Ex)   {    MessageBox.Show(Ex.ToString(), "提示");   }   }   //使線程睡眠，使過程清楚顯示，且有時間掛起線程   Thread.Sleep(500);  }  //除2外，素數必為奇數，故跳過偶數的檢查，優化算法  NumberNow += 2;  } } //更新ListBox的方法 void UpdateUI(string result) {  listBox1.Items.Add(result); } //利用Timer控件顯示線程當前狀態 private void timer1_Tick(object sender, System.EventArgs e) {  //在線程開時候再獲取狀態并顯示  if( pNTstart )  {  label2.Text = "線程當前狀態是：" + pNT.ThreadState.ToString();  } } private void Form1_Load(object sender, System.EventArgs e) {  //設置按鍵，啟用開始按鍵，停用其他按鍵  button1.Enabled = true;  button2.Enabled = false;  button3.Enabled = false;  button4.Enabled = false; } }}