public partial class Form1 : Form

{

    public Form1()

    {

        InitializeComponent();

    }

    int current = 0;

    private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)

    {

        progressBar1.Maximum = (int)numericUpDown1.Value;

        for (int i = 0; i < progressBar1.Maximum; i++)

        {

            System.Threading.Thread.Sleep(10);

            backgroundWorker1.ReportProgress(++current);

        }

        //MessageBox.Show(current.ToString());   

    }

    private void Form1_Load(object sender, EventArgs e)

    {

    }

    private void button1_Click(object sender, EventArgs e)

    {

        try { int.Parse(numericUpDown1.Text); }

        catch

        {

            MessageBox.Show("工作量必须为数字！");

            return;

        }

        if (backgroundWorker1.IsBusy)

        {

            MessageBox.Show("已经在处理中，请稍后！");

            return;

        }

        backgroundWorker1.RunWorkerAsync();

    }

    private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e)

    {

        progressBar1.Value = e.ProgressPercentage;

    }

    private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)

    {

        progressBar1.Value = 0;

        MessageBox.Show("OK<");

    }

}