BackgroundWorker进度条，以及文件夹共享的问题？

Question

public partial class MainForm : Form
    {
        private System.ComponentModel.BackgroundWorker backgroundCalculator;        public MainForm()
        {
            InitializeComponent();
            backgroundCalculator = new BackgroundWorker();
            backgroundCalculator.WorkerReportsProgress = true;
            backgroundCalculator.WorkerSupportsCancellation = true;
            backgroundCalculator.DoWork +=                      new DoWorkEventHandler(backgroundCalculator_DoWork);
            backgroundCalculator.ProgressChanged +=                      new ProgressChangedEventHandler(backgroundCalculator_ProgressChanged);
            backgroundCalculator.RunWorkerCompleted +=                      new RunWorkerCompletedEventHandler(backgroundCalculator_RunWorkerCompleted);
            updateStatus(String.Empty);
        }
 
        private int getNextPrimeAsync(int start, BackgroundWorker worker, DoWorkEventArgs e)
        {
            int percentComplete = 0;            start++;
            while (!isPrime(start))
            {
                // Check for cancellation
                if (worker.CancellationPending)
                {
                    e.Cancel = true;
                    break;
                }
                else
                {
                    start++;
                    percentComplete++;
      
                    worker.ReportProgress(percentComplete % 100);
                }
            }
            return start;
        }        void backgroundCalculator_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
            if (e.Cancelled)
            {
                updateStatus("Cancelled.");
            }
            else if (e.Error != null)
            {
                reportError(e.Error);
            }
            else
            {
                reportPrime((int)e.Result);
            }
            calcProgress.Value = 0;
        }        void backgroundCalculator_ProgressChanged(object sender, ProgressChangedEventArgs e)
        {
            updateProgress(e.ProgressPercentage);
        }
        void backgroundCalculator_DoWork(object sender, DoWorkEventArgs e)
        {
            int start = (int) e.Argument;
            e.Result = getNextPrimeAsync(start, (BackgroundWorker)sender, e);
        }        private void nextPrimeAsyncButton_Click(object sender, EventArgs e)
        {
            updateStatus("Calculating...");            int start;
            Int32.TryParse(textBoxPrime.Text, out start);            if (start == 0)
            {
                reportError("The number must be a valid integer");
            }
            else
            {
                // Kick off the background worker process
                backgroundCalculator.RunWorkerAsync(int.Parse(textBoxPrime.Text));
            }
        }        private void cancelButton_Click(object sender, EventArgs e)
        {
            if (backgroundCalculator.IsBusy)
            {
                updateStatus("Cancelling...");
                backgroundCalculator.CancelAsync();
            }
        }        // Update the Status label
        private void updateStatus(string status)
        {
            calcStatus.Text = status;
        }        // Indicate progress using progress bar
        private void updateProgress(int percentComplete)
        {
            calcProgress.Value = percentComplete;
        }
    }

Answer 1

1. 从工具栏拖一个BackgroundWorker控件，设置其属性WorkerReportsProgress为true2. 要让worker开始工作，执行如下代码：
    mBackgroundWorker.RunWorkerAsync(arg);
    这里有重写，如果不需要传递参数直接mBackgroundWorker.RunWorkerAsync();3. 编辑DoWork事件代码：
    e.Argument为mBackgroundWorker.RunWorkerAsync(arg);对应的参数
    之所以使用进度条，肯定是有循环的，在循环中报告进度：
    worker.ReportProgress(i * 100 / num, obj );
    其中第一个参数是当前进度的百分之多少，obj为你要传递的UserState，如果没有可以不要4. 编辑ProgressChanged事件代码：
    e.ProgressPercentage为进度的百分数，e.UserState为刚才传递过来的object
    在这个事件中可以调用ui的进度条和其他控件：
    mToolStripProgressBar.Value = e.ProgressPercentage;5. 编辑RunWorkerCompleted事件代码：