通过引用Winform传递哈希表；在取消BGW时，此变量在BGW中的用法不会更新最初传递的哈希表

private ConcurrentDictionary<string, int> sharedHashTable = new ConcurrentDictionary<string, int>();
private BackgroundWorker bgw;

public Form1()
{
    InitializeComponent();
    bgw = new BackgroundWorker();
    bgw.WorkerSupportsCancellation = true;
    bgw.DoWork += Bgw_DoWork;
    bgw.RunWorkerCompleted += Bgw_RunWorkerCompleted;
}

private void StartButton_Click(object sender, EventArgs e)
{
    sharedHashTable["Key"] = 0; // 初始化哈希表
    bgw.RunWorkerAsync(sharedHashTable);
}

private void Bgw_DoWork(object sender, DoWorkEventArgs e)
{
    var hashTable = (ConcurrentDictionary<string, int>)e.Argument;
    while (!bgw.CancellationPending)
    {
        // 模拟工作
        Thread.Sleep(100);
        hashTable.AddOrUpdate("Key", 1, (key, oldValue) => oldValue + 1);
    }
    if (bgw.CancellationPending)
    {
        // 取消操作时更新哈希表
        hashTable["Key"] = -1; // 示例取消标记
    }
}

private void Bgw_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
    if (e.Cancelled)
    {
        MessageBox.Show("操作已取消");
    }
    else if (e.Error != null)
    {
        MessageBox.Show("发生错误: " + e.Error.Message);
    }
    else
    {
        MessageBox.Show("操作完成");
    }
}

private void CancelButton_Click(object sender, EventArgs e)
{
    bgw.CancelAsync();
}