winform中执行任务,解决未响应界面

private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
        {
            var count = (int)e.Argument;
            for (int i = 1; i <= count; i++)
            {
                if (backgroundWorker1.CancellationPending)
                {
                    e.Cancel = true;
                    return;
                }

//if (i == 2)
                //    throw new Exception("出错啦！");

backgroundWorker1.ReportProgress(i);
                //任务             
                Thread.Sleep(500);//模拟耗时的任务              
            }
        }

private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e)
        {
            toolStripProgressBar1.Value = e.ProgressPercentage;
            toolStripStatusLabel1.Text = DateTime.Now.ToString();
        }
        //更新UI,异常处理
        private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
            if (e.Cancelled)
                toolStripStatusLabel1.Text += "任务取消。";
            else if (e.Error != null)
                toolStripStatusLabel1.Text += "出现异常: " + e.Error;
            else
                toolStripStatusLabel1.Text += "任务完成。 ";
        }

private void button1_Click(object sender, EventArgs e)
        {
            if (!backgroundWorker1.IsBusy)
            {
                toolStripProgressBar1.Value = 0;
                toolStripProgressBar1.Maximum = 100;

toolStripStatusLabel1.Text = "任务开始...";
                //标记
                backgroundWorker1.RunWorkerAsync(100);
            }
            else
            {
                MessageBox.Show("正在进行异步操作.");
            }
        }

private void button2_Click(object sender, EventArgs e)
        {
            backgroundWorker1.CancelAsync();
        }