1 using System;  2 using System.Collections.Generic;  3 using System.ComponentModel;  4 using System.Data;  5 using System.Drawing;  6 using System.Linq;  7 using System.Text;  8 using System.Windows.Forms;  9  10 namespace BackgroundWorkerTest 11 { 12     public partial class Form2 : Form 13     { 14         /* 15          * 使用BackgroundWorker的用法很多 16          * 1.可以直接从左边控件列表中拖一个到界面中 17          * 2.动态写代码生成，这里我是把它作为成员变量了 18          * **/ 19         private BackgroundWorker _worker = new BackgroundWorker(); 20  21         public Form2() 22         { 23             InitializeComponent(); 24  25             //设置是否允许报告进度 26             _worker.WorkerReportsProgress = true; 27             //设置是否允许取消 28             _worker.WorkerSupportsCancellation = true; 29  30  31             //BackgroundWorker的三个事件之一，异步处理是所要执行的动作 32             _worker.DoWork += new DoWorkEventHandler(_worker_DoWork); 33  34             //BackgroundWorker的三个事件之二，当进度改变时所要执行的动作 35             _worker.ProgressChanged += new ProgressChangedEventHandler(_worker_ProgressChanged); 36  37             //BackgroundWorker的三个事件之三，当任务正常完成或手动取消时，所要执行的动作 38             _worker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(_worker_RunWorkerCompleted); 39         } 40  41  42         //运行RunWorkerAsync()时就出发此方法，而且此方法不能与UI有交互，会抛异常 43         void _worker_DoWork(object sender, DoWorkEventArgs e) 44         { 45             //这个类是用来测试报告进度时，除了可以报告进度外，还可以返回一个object的变量 46             Person tommy = new Person("Tommy.Huang","25","CXY"); 47  48             for (int i = 1; i <= 100; i++) 49             { 50                 //如果想要实现能够中途取消的功能，就必须在DoWork里面判断是否点击了取消 51                 //CancellationPending用于判断是运行了CancelAsync()方法 52                 if (_worker.CancellationPending) 53                 { 54                     e.Cancel = true; 55                     break; 56                 } 57                 else 58                 { 59                     _worker.ReportProgress(i,tommy);//ReportProgress可以带1个或2个参数，第一个为进度int，第二个为object 60                     //因为太快，看不到效果，所以让线程每一次暂停半秒 61                     System.Threading.Thread.Sleep(100); 62                 } 63             } 64         } 65  66         //当进度有所改变时，就会触发该方法，此方法可以与UI交互，所以通常在此方法中处理 67         void _worker_ProgressChanged(object sender, ProgressChangedEventArgs e) 68         { 69             Person p = e.UserState as Person; 70             this.label1.Text = e.ProgressPercentage.ToString()+"% -"+p.Name; 71         } 72  73         //当异步线程正常运行结束，或者点击取消时都会执行此方法 74         void _worker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e) 75         { 76             if (e.Cancelled) 77                 System.Windows.Forms.MessageBox.Show("取消了"); 78             else 79                 System.Windows.Forms.MessageBox.Show("完成了！"); 80         } 81  82         private void btnStart_Click(object sender, EventArgs e) 83         { 84             //需要先判断backgroundWorker是否正在运行 85             if (!_worker.IsBusy) 86             { 87                 //RunWorkerAsync()启动线程 88                 _worker.RunWorkerAsync(); 89             } 90         } 91  92         private void btnCancel_Click(object sender, EventArgs e) 93         { 94             //先判断backgroundWorker是否支持取消 95             if (_worker.WorkerSupportsCancellation) 96             { 97                 //CancelAsync()取消线程 98                 _worker.CancelAsync(); 99             }100         }101 102     }103 }

 1 namespace BackgroundWorkerTest 2 { 3     partial class Form2 4     { 5         /// <summary> 6         /// Required designer variable. 7         /// </summary> 8         private System.ComponentModel.IContainer components = null; 9 10         /// <summary>11         /// Clean up any resources being used.12         /// </summary>13         /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>14         protected override void Dispose(bool disposing)15         {16             if (disposing && (components != null))17             {18                 components.Dispose();19             }20             base.Dispose(disposing);21         }22 23         #region Windows Form Designer generated code24 25         /// <summary>26         /// Required method for Designer support - do not modify27         /// the contents of this method with the code editor.28         /// </summary>29         private void InitializeComponent()30         {31             this.btnStart = new System.Windows.Forms.Button();32             this.btnCancel = new System.Windows.Forms.Button();33             this.label1 = new System.Windows.Forms.Label();34             this.SuspendLayout();35             // 36             // btnStart37             // 38             this.btnStart.Location = new System.Drawing.Point(42, 165);39             this.btnStart.Name = "btnStart";40             this.btnStart.Size = new System.Drawing.Size(75, 23);41             this.btnStart.TabIndex = 0;42             this.btnStart.Text = "开始";43             this.btnStart.UseVisualStyleBackColor = true;44             this.btnStart.Click += new System.EventHandler(this.btnStart_Click);45             // 46             // btnCancel47             // 48             this.btnCancel.Location = new System.Drawing.Point(249, 165);49             this.btnCancel.Name = "btnCancel";50             this.btnCancel.Size = new System.Drawing.Size(75, 23);51             this.btnCancel.TabIndex = 1;52             this.btnCancel.Text = "取消";53             this.btnCancel.UseVisualStyleBackColor = true;54             this.btnCancel.Click += new System.EventHandler(this.btnCancel_Click);55             // 56             // label157             // 58             this.label1.AutoSize = true;59             this.label1.Location = new System.Drawing.Point(61, 47);60             this.label1.Name = "label1";61             this.label1.Size = new System.Drawing.Size(35, 13);62             this.label1.TabIndex = 2;63             this.label1.Text = "label1";64             // 65             // Form266             // 67             this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);68             this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;69             this.ClientSize = new System.Drawing.Size(388, 230);70             this.Controls.Add(this.label1);71             this.Controls.Add(this.btnCancel);72             this.Controls.Add(this.btnStart);73             this.Name = "Form2";74             this.Text = "Form2";75             this.ResumeLayout(false);76             this.PerformLayout();77 78         }79 80         #endregion81 82         private System.Windows.Forms.Button btnStart;83         private System.Windows.Forms.Button btnCancel;84         private System.Windows.Forms.Label label1;85     }86 }