链接：http://www.cnblogs.com/yiyisawa/archive/2008/11/24/1339826.html
周六闲来无事，学习了多线程BackgroundWorker，以此记录。
此案例功能：
实现用BackgroundWorker处理进度条，可以开始，暂停，继续，清空。
BackgroundWorker说明： 摘抄自---http://msdn.microsoft.com
BackgroundWorker 类允许您在单独的专用线程上运行操作。耗时的操作（如下载和数据库事务）在长时间运行时可能会导致用户界面 (UI) 似乎处于停止响应状态。如果您需要能进行响应的用户界面，而且面临与这类操作相关的长时间延迟，则可以使用 BackgroundWorker 类方便地解决问题。若要在后台执行耗时的操作，请创建一个 BackgroundWorker，侦听那些报告操作进度并在操作完成时发出信号的事件。可以通过编程方式创建 BackgroundWorker，也可以将它从“工具箱”的“组件”选项卡中拖到窗体上。如果在 Windows 窗体设计器中创建 BackgroundWorker，则它会出现在组件栏中，而且它的属性会显示在“属性”窗口中。若要设置后台操作，请为 DoWork 事件添加一个事件处理程序。在此事件处理程序中调用耗时的操作。若要启动该操作，请调用 RunWorkerAsync。若要收到进度更新通知，请对 ProgressChanged 事件进行处理。若要在操作完成时收到通知，请对 RunWorkerCompleted 事件进行处理。
您必须非常小心，确保在 DoWork 事件处理程序中不操作任何用户界面对象。而应该通过 ProgressChanged 和 RunWorkerCompleted 事件与用户界面进行通信。
BackgroundWorker 事件不跨 AppDomain 边界进行封送处理。请不要使用 BackgroundWorker 组件在多个 AppDomain 中执行多线程操作。如果后台操作需要参数，请在调用 RunWorkerAsync 时给出参数。在 DoWork 事件处理程序内部，可以从 DoWorkEventArgs..::.Argument 属性中提取该参数。
namespace WindowsApplication1{ partial class Form1 { /// <summary> /// Required designer variable. /// </summary> private System.ComponentModel.IContainer components = null; /// <summary> /// Clean up any resources being used. /// </summary> /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param> protected override void Dispose(bool disposing) { if (disposing && (components != null)) { components.Dispose(); } base.Dispose(disposing); } #region Windows Form Designer generated code /// <summary> /// Required method for Designer support - do not modify /// the contents of this method with the code editor. /// </summary> private void InitializeComponent() { this.colorDialog1 = new System.Windows.Forms.ColorDialog(); this.colorDialog2 = new System.Windows.Forms.ColorDialog(); this.progressBar1 = new System.Windows.Forms.ProgressBar(); this.button1 = new System.Windows.Forms.Button(); this.button2 = new System.Windows.Forms.Button(); this.button3 = new System.Windows.Forms.Button(); this.textBox2 = new System.Windows.Forms.TextBox(); this.backgroundWorker1 = new System.ComponentModel.BackgroundWorker(); this.label3 = new System.Windows.Forms.Label(); this.label1 = new System.Windows.Forms.Label(); this.button4 = new System.Windows.Forms.Button(); this.SuspendLayout(); // // progressBar1 // this.progressBar1.Location = new System.Drawing.Point(27, 85); this.progressBar1.Name = "progressBar1"; this.progressBar1.Size = new System.Drawing.Size(218, 23); this.progressBar1.TabIndex = 0; // // button1 // this.button1.Location = new System.Drawing.Point(12, 222); this.button1.Name = "button1"; this.button1.Size = new System.Drawing.Size(54, 23); this.button1.TabIndex = 1; this.button1.Text = "Execute "; this.button1.UseVisualStyleBackColor = true; this.button1.Click += new System.EventHandler(this.button1_Click); // // button2 // this.button2.Location = new System.Drawing.Point(72, 222); this.button2.Name = "button2"; this.button2.Size = new System.Drawing.Size(53, 23); this.button2.TabIndex = 2; this.button2.Text = "Cancel"; this.button2.UseVisualStyleBackColor = true; this.button2.Click += new System.EventHandler(this.button2_Click); // // button3 // this.button3.Location = new System.Drawing.Point(131, 222); this.button3.Name = "button3"; this.button3.Size = new System.Drawing.Size(57, 23); this.button3.TabIndex = 3; this.button3.Text = "Continue "; this.button3.UseVisualStyleBackColor = true; this.button3.Click += new System.EventHandler(this.button3_Click); // // textBox2 // this.textBox2.Location = new System.Drawing.Point(145, 124); this.textBox2.Name = "textBox2"; this.textBox2.Size = new System.Drawing.Size(100, 20); this.textBox2.TabIndex = 5; // // backgroundWorker1 // this.backgroundWorker1.WorkerReportsProgress = true; this.backgroundWorker1.WorkerSupportsCancellation = true; this.backgroundWorker1.DoWork += new System.ComponentModel.DoWorkEventHandler(this.backgroundWorker1_DoWork); this.backgroundWorker1.RunWorkerCompleted += new System.ComponentModel.RunWorkerCompletedEventHandler(this.backgroundWorker1_RunWorkerCompleted); this.backgroundWorker1.ProgressChanged += new System.ComponentModel.ProgressChangedEventHandler(this.backgroundWorker1_ProgressChanged); // // label3 // this.label3.AutoSize = true; this.label3.Location = new System.Drawing.Point(33, 175); this.label3.Name = "label3"; this.label3.Size = new System.Drawing.Size(54, 13); this.label3.TabIndex = 6; this.label3.Text = "UserState"; // // label1 // this.label1.AutoSize = true; this.label1.Location = new System.Drawing.Point(24, 127); this.label1.Name = "label1"; this.label1.Size = new System.Drawing.Size(109, 13); this.label1.TabIndex = 7; this.label1.Text = "Please input number:"; // // button4 // this.button4.Location = new System.Drawing.Point(194, 222); this.button4.Name = "button4"; this.button4.Size = new System.Drawing.Size(61, 23); this.button4.TabIndex = 8; this.button4.Text = "Clear"; this.button4.UseVisualStyleBackColor = true; this.button4.Click += new System.EventHandler(this.button4_Click); // // Form1 // this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F); this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font; this.ClientSize = new System.Drawing.Size(292, 273); this.Controls.Add(this.button4); this.Controls.Add(this.label1); this.Controls.Add(this.label3); this.Controls.Add(this.textBox2); this.Controls.Add(this.button3); this.Controls.Add(this.button2); this.Controls.Add(this.button1); this.Controls.Add(this.progressBar1); this.Name = "Form1"; this.Text = "Form1"; this.ResumeLayout(false); this.PerformLayout(); } #endregion private System.Windows.Forms.ColorDialog colorDialog1; private System.Windows.Forms.ColorDialog colorDialog2; private System.Windows.Forms.ProgressBar progressBar1; private System.Windows.Forms.Button button1; private System.Windows.Forms.Button button2; private System.Windows.Forms.Button button3; private System.Windows.Forms.TextBox textBox2; private System.ComponentModel.BackgroundWorker backgroundWorker1; private System.Windows.Forms.Label label3; private System.Windows.Forms.Label label1; private System.Windows.Forms.Button button4; }}
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;using System.Net;namespace WindowsApplication1{ public partial class Form1 : Form { //加载窗体 public Form1() { InitializeComponent(); } #region define int i = 0; int j = 0; bool f = false; #endregion private void button1_Click(object sender, EventArgs e) { backgroundWorker1.RunWorkerAsync(); } //按钮单击事件启动后台线程DoWok事件 private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e) { BackgroundWorker worker = (BackgroundWorker)sender; int num = int.Parse(textBox2.Text); if (f == false) { for (i = 0; i < num; i++) { if (!worker.CancellationPending) { j = i; Thread.Sleep(100); worker.ReportProgress(i * 100 / num, i); if (backgroundWorker1.CancellationPending) { e.Cancel = true; break; } } } } else { for (i = j; i < num; i++) { if (!worker.CancellationPending) { j = i; Thread.Sleep(100); worker.ReportProgress(i * 100 / num, i); if (backgroundWorker1.CancellationPending) { e.Cancel = true; break; } } } } } private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e) { progressBar1.Value = e.ProgressPercentage; label3.Text = e.UserState.ToString(); } private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e) { if (e.Cancelled) { label3.Text = "已经取消！"; } else { MessageBox.Show("ok"); } } private void button2_Click(object sender, EventArgs e) { backgroundWorker1.CancelAsync(); label3.Text = "正在取消。。"; } private void button3_Click(object sender, EventArgs e) { f = true; backgroundWorker1.RunWorkerAsync(); } private void button4_Click(object sender, EventArgs e) { backgroundWorker1.CancelAsync(); this.progressBar1.Value = 0; f = false; this.label3.Text = ""; this.textBox2.Text = ""; } }}