c# 异步进度条组件BackgroundWorker

//控件事件调用DoWork()方法就行。
   
#region 进度条
        private BackgroundWorker worker = null;

        private void DoWork(string outfile)
        {
            //显示进度条
            ProgressForm progressForm = new ProgressForm();
            progressForm.TopMost = true;
            progressForm.Show(this);

            //准备进度条的记数
            worker = new BackgroundWorker();
            //指定提供进度通知
            worker.WorkerReportsProgress = true;
            //提供中断功能
            worker.WorkerSupportsCancellation = true;
            //线程的主要功能是处理事件
            //开启线程执行工作
            worker.DoWork += new DoWorkEventHandler(worker_DoWork);
            // Specify the function to use to handle progress
            //指定使用的功能来处理进度
            worker.ProgressChanged += new ProgressChangedEventHandler(progressForm.OnProgressChanged);
            worker.ProgressChanged += new ProgressChangedEventHandler(worker_ProgressChanged);
            //进度条结束完成工作
            //1.工作完成
            //2.工作错误异常
            //3.取消工作
            worker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(progressForm.OnProcessCompleted);
            worker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(worker_RunWorkerCompleted);
            //如果进度条需要参数
            //调用System.ComponentModel.BackgroundWorker.RunWorkerAsync
            //传入你的参数至System.ComponentModel.BackgroundWorker.DoWork 
            //提取参数
            //System.ComponentModel.DoWorkEventArgs.Argument 

            worker.RunWorkerAsync(outfile);
        }

        //单线程执行工作
        private void worker_DoWork(object sender, DoWorkEventArgs e)
        {
            try
            {
                worker_Doing((BackgroundWorker)sender, e);
            }
            catch (Exception ex)
            {
                //此处为异常处理，不能放到worker_Doing内部
                e.Result = ex;
            }
        }

        //进行工作
        private void worker_Doing(BackgroundWorker worker, DoWorkEventArgs e)
        {
            string outfile = e.Argument as string; //传入参数
            int count = 500;
            for (int i = 0; i < count; i++)
            {
                //检查取消
                if (worker.CancellationPending)
                {
                    e.Cancel = true;
                    break;
                }
                else
                {
                    //此处为具体的工作代码
                    //...

                    //进度报告
                    worker.ReportProgress((i + 1) * (100 / count), "进度信息");
                    //线程休眠
                    Thread.Sleep(500);

                }

            }

        }
        
        //进度报告
        private void worker_ProgressChanged(object sender, ProgressChangedEventArgs e)
        {
            //此处可在窗口显示进度信息
            //e.UserState as string
            //...

        }

        //工作完成状态
        private void worker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
            string message = "";
            if (e.Error != null)
            {
                message = e.Error.Message;
                MessageBox.Show(this, message, "异常");
            }
            else if (e.Cancelled)
            {
                message = "操作被取消。";
                MessageBox.Show(this, message, "提示");
            }
            else
            {
                if (e.Result == null)
                {
                    message = "完成。";
                    MessageBox.Show(this, message, "信息");
                }
                else
                {
                    message = (e.Result as Exception).Message;
                    MessageBox.Show(this, message, "异常");
                }
            }

            //此处代码为完成后的处理工作
            //...
        }
        #endregion