C#多线程BackgroundWorker使用示例

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 BackgroundWorkerSample
{
<wbr><wbr><wbr> public partial class CalculateAddForm : Form<br><wbr><wbr><wbr> {<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr> protected BackgroundWorker backgroundWorker1 = new BackgroundWorker();<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr> //private int numberToCompute = 0;<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr> //private int highestPercentageReached<wbr> = 0;</wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><wbr><wbr> public CalculateAddForm()<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr> {<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr> InitializeComponent();</wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr> InitializeBackgoundWorke<wbr>r();<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><br><wbr><wbr><wbr><wbr><wbr><wbr><wbr> }</wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><wbr><wbr> // Set up the BackgroundWorker object by<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr> // attaching event handlers.<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr> private void InitializeBackgoundWorke<wbr>r()<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr> {<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr> this.backgroundWorker1.WorkerReportsProgress = true;<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr> this.backgroundWorker1.WorkerSupportsCancellati<wbr>on = true;<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr> this.backgroundWorker1.DoWork += new DoWorkEventHandler(backgroundWorker1_DoWork);<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr> this.backgroundWorker1.ProgressChanged += new ProgressChangedEventHand<wbr>ler(backgroundWorker1_ProgressChanged);<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr> this.backgroundWorker1.RunWorkerCompleted += new RunWorkerCompletedEventH<wbr>andler(backgroundWorker1_RunWorkerCompleted);<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr> }</wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><wbr><wbr> private long ComputeAdd(int n, BackgroundWorker worker, DoWorkEventArgs e)<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr> {<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr> long result = 0;</wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr> // Abort the operation if the user has canceled.<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr> // Note that a call to CancelAsync may have set<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr> // CancellationPending to true just after the<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr> // last invocation of this method exits, so this<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr> // code will not have the opportunity to set the<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr> // DoWorkEventArgs.Cancel flag to true. This means<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr> // that RunWorkerCompletedEventA<wbr>rgs.Cancelled will<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr> // not be set to true in your RunWorkerCompleted<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr> // event handler. This is a race condition.</wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr> for (int i = 1; i &lt;= n; i++)<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr> {<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr> if (worker.CancellationPending)<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr> {<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr> e.Cancel = true;<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr> break;<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr> }<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr> else<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr> {<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr> result += i;<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr> Thread.Sleep(100);<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr> // Report progress as a percentage of the total task.<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr> int percentComplete = (int)((float)i / (float)n * 100);<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr> worker.ReportProgress(percentComplete);<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr> }<br><wbr><wbr><wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr>