使用 BackgroundWorker 執行任務並監控線程進度

前言：

該示例適用於任務執行時返回進度。

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示例

示例 UI 基本爲如下圖

示例代碼如下

    private BackgroundWorker _bw;
    
    /// <summary>
    /// 開始按鈕
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    private void StartButton_Click(object sender, EventArgs e)
    {
        StartButton.Enabled = false;
        _bw = new BackgroundWorker();
        // 可以異步取消
        _bw.WorkerSupportsCancellation = true;
        // 可以報告進度
        _bw.WorkerReportsProgress = true;
        _bw.DoWork += (_, args) =>
        {
            // 任務內容
            for (int i = 1; i <= 100; i++)
            {
                if (_bw.CancellationPending)
                    break;
                _bw.ReportProgress(i, i.ToString());
                Thread.Sleep(200);
            }
        };
    
        _bw.ProgressChanged += (obj, agrs) =>
        {
            // 報告進度
            ProgressBar.Text = agrs.UserState.ToString();
        };
    
        _bw.RunWorkerCompleted += (_, agrs) =>
        {
            // 任務完成
            StartButton.Enabled = true;
            ProgressBar.Text += " 完成";
        };
    
        _bw.RunWorkerAsync();
    }
    
    /// <summary>
    /// 停止按鈕
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    private void StopButton_Click(object sender, EventArgs e)
    {
        if (_bw != null)
            _bw.CancelAsync();
    }