关于使用BackgroundWorker多条线程如何控制暂完成和暂停
下面的代码，界面开启运行后，点启动后，完成后能正确输出操作完成，点击启动后立即暂停也是能正确输出操作暂停。

问题在于点启动后，再点暂停，再点启动，等完成后不会输出操作完成。
点启动后，再点暂停，再点启动，再点暂停也是不能输出操作暂停。

请问下面代码问题出在哪里，怎么修改才能正确输出。

List<BackgroundWorker> bw = new List<BackgroundWorker>();
        int t = 10;
        int c = 1;

        public Form2()
        {
            InitializeComponent();

            for (int i = 0; i < t; i++)
            {
                bw.Add(new BackgroundWorker());
                bw[i].WorkerSupportsCancellation = true;
                bw[i].DoWork += new DoWorkEventHandler(bw_DoWork);
                bw[i].RunWorkerCompleted += new RunWorkerCompletedEventHandler(bw_RunWorkerCompleted);
            }
        }

        void bw_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
            if (c++ == t)
            {
                if (e.Cancelled)
                {
                    this.richTextBox1.Text += "操作暂停！"; ;
                }
                else
                {
                    this.richTextBox1.Text += "操作完成！";
                }
            }
        }

        void bw_DoWork(object sender, DoWorkEventArgs e)
        {
            int j = Convert.ToInt32(e.Argument);

            for (int i = j; i < 100; i = i + t)
            {

                if (((BackgroundWorker)sender).CancellationPending) 
 
                {
                    e.Cancel = true;
                    return;
                }

                string s1 = DateTime.Now.ToString("hh:mm:ss");
                string s2 = (j+1).ToString();

                this.Invoke((MethodInvoker)delegate
                {
                    this.richTextBox1.Text += String.Format("时间：{0}-线程：{1}-数据：{2}", s1, s2, i) + Environment.NewLine;
                });
                System.Threading.Thread.Sleep(200);
            }
        }

        private void button1_Click(object sender, EventArgs e)
        {
            this.button1.Enabled = false;
            this.button2.Enabled = true;

            this.richTextBox1.Text = String.Empty;

            this.RunWorkerAsync();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            this.button1.Enabled = true;
            this.button2.Enabled = false;

            this.CancelAsync();
        }

        private void richTextBox1_TextChanged(object sender, EventArgs e)
        {
            RichTextBox textbox = (RichTextBox)sender;

            textbox.SelectionStart = textbox.Text.Length;
            textbox.SelectionLength = 0;
            textbox.ScrollToCaret();
        }

        private void RunWorkerAsync()
        {
            for (int i = 0; i < t; i++)
            { 
 
                bw[i].RunWorkerAsync(i);
            }
        }

        private void CancelAsync()
        {
            for (int i = 0; i < t; i++)
            {
                bw[i].CancelAsync();
            }
        }

[解决办法]
private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
{
//处理
object[] argumet = (object[])e.Argument;
int rowIndex = (int)argumet[0];//处理到第几条命令
...
//返回进度
backgroundWorker1.ReportProgress(rowIndex, new object[] {... });
//返回结果
e.Result = new object[] { rowIndex, ...};
}
private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
//显示进度情况
...
}
//完成一次处理
private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
//接收返回的结果
object[] argumet = (object[])e.Result;
int rowIndex = (int)argumet[0];
rowIndex = rowIndex + 1;//累计加1
....
//判断是否已完成所以命令,在这里也可以加上暂停的判断if (rowIndex < _rowcount && !isStop)
if (rowIndex < _rowcount)
{
object argumet2 = new object[] { rowIndex, .. };
backgroundWorker1.RunWorkerAsync(argumet2);//处理下一条信息
}
}


//第一次执行


object argumet2 = new object[] { 0, .. };
backgroundWorker1.RunWorkerAsync(argumet2);//处理下一条信息