DataGridView更新/刷新问题

我有一个windows窗体，它有以下代码

BindingList<TicketResult> tickResults = new BindingList<TicketResult>();
BindingSource bindingSource1 = new BindingSource();
Action<String> call;
private void method(String x)
{
    if (this.dataGridView1.InvokeRequired)
    {
        lock (this)
        {                    
            dataGridView1.Invoke(
            new MethodInvoker(() =>
            {
                Debug.WriteLine(x);
                tickResults[int.Parse(x)].Row = "first page";
                dataGridView1.Refresh();
            }));
        }
    }
}
public Form1()
{
    call = method;
    ServicePointManager.DefaultConnectionLimit = 48;
    InitializeComponent();
    tickResults.ListChanged += tickResults_ListChanged;
    for (int i = 0; i < 10; i++)
    {
        TicketResult result = new TicketResult();                
        tickResults.Add(result);
    }
    bindingSource1.DataSource = tickResults;
    dataGridView1.DataSource = bindingSource1;

    for (int i = 0; i < 10; i++)
    {
        Search s = new Search();
        int x = i;
        Task.Run(() => s.start(x, this.call));
    }

}

我不明白为什么不调用dataGridView1's Refresh()方法而不反映tickResults的变化。

在表单中调用"call"委托的其他类的代码如下:

class Search : ISearch
{
    public async Task<bool> start(int i, Action<String> x)
    {
        bool result = false;
        TicketLogic tixLogic = new TicketLogic();
        try
        {
            await Task.Run(() => tixLogic.processFirstPage(i, x))
                .ContinueWith((t) => tixLogic.processSecondPage(i, x))
                .ContinueWith((t) => tixLogic.processThirdPage(i, x));               
            result = true;
        }
        catch (Exception e)
        {
            Debug.WriteLine(e.Message);
            result = false;
        }
        return result;
    }
    public async Task<bool> stop()
    {
        return false;
    }
    public async Task<bool> restart()
    {
        return false;
    }
}
class TicketLogic
{
    public async Task<bool> processFirstPage(int i, Action<String> x)
    {
        bool result = false;            
        try
        {
            HttpWebRequest request = WebRequest.CreateHttp("http://www.google.com");
            WebResponse response = await request.GetResponseAsync();
            StreamReader reader = new StreamReader(response.GetResponseStream());
            String textResponse = await reader.ReadToEndAsync();                
            reader.Close();
            response.Close();              
            result = true;
        }
        catch (Exception e)
        {
            Debug.WriteLine(e.Message);
            result = false;
        }
        return result;
    }
    public async Task<bool> processSecondPage(int i, Action<String> x)
    {
        bool result = false;            
        try
        {
            HttpWebRequest request = WebRequest.CreateHttp("http://www.example.com");
            WebResponse response = await request.GetResponseAsync();
            StreamReader reader = new StreamReader(response.GetResponseStream());
            String textResponse = await reader.ReadToEndAsync();
            //tixResult.Information = "Second Page";
            reader.Close();
            response.Close();
            x(i.ToString());
            result = true;
        }
        catch (Exception e)
        {
            Debug.WriteLine(e.Message);
            result = false;
        }
        return result;
    }
    public async Task<bool> processThirdPage(int i, Action<String> x)
    {
        bool result = false;
        try
        {
            HttpWebRequest request = WebRequest.CreateHttp("http://www.hotmail.com");
            WebResponse response = await request.GetResponseAsync();
            StreamReader reader = new StreamReader(response.GetResponseStream());
            String textResponse = await reader.ReadToEndAsync();
            //tixResult.Information = "Third Page";
            reader.Close();
            response.Close();
            x(i.ToString());
            result = true;
        }
        catch (Exception e)
        {
            Debug.WriteLine(e.Message);
            result = false;
        }
        return result;
    }
}

在此之前，我尝试了另一种方法，其中我将数据绑定对象传递给计算任务，在那里数据绑定对象被操纵，但即使有结果是相同的，即在对象的变化没有反映在网格上，直到我点击网格中的一些单元格或最小化/最大化的形式。

我的问题是，为什么没有调用datagrid refresh()的变化没有反映在网格中?