private async void btnStartAnonum_Click(object sender, EventArgs e)
{
btnStartAnonum.Text = "Cancel";
if (cancellationTokenSource != null)
{
cancellationTokenSource.Cancel();
cancellationTokenSource = null;
return;
}
cancellationTokenSource = new CancellationTokenSource();
try
{
var service = new StockService();
var operation = Task.Factory.StartNew(async(obj) => // obj is the service
{
var stockService = obj as StockService;
var prices = await stockService.SearchForStocks("MSFT", cancellationTokenSource.Token);
return(prices.Take(5));
}, service)// pass as obj into lambda
.Unwrap();
//var result = await await operation;// without Unwrap()
var result = await operation;
Debug.WriteLine("Process completed");
}
catch (Exception ex)
{
textBox1.Text = ex.Message;
}
finally
{
cancellationTokenSource = null;
}
btnStartAnonum.Text = "19 StartAnonum";
}
private async void btnOneByOne_Click(object sender, EventArgs e)
{
btnOneByOne.Text = "Cancel";
if (cancellationTokenSource != null)
{
cancellationTokenSource.Cancel();
cancellationTokenSource = null;
return;
}
cancellationTokenSource = new CancellationTokenSource();
cancellationTokenSource.Token.Register(() => { textBox1.Text = "Cancellation requested"; });
try
{
var tickers = tbTickers.Text.Split(',', ' ');
var tickerLoadingTasks = new List <Task <IEnumerable <StockPrice> > >();
var service = new StockService();
var stocks = new ConcurrentBag <StockPrice>();//thread safe collection
foreach (var item in tickers)
{
var loadedLines = service.SearchForStocks(item, cancellationTokenSource.Token)
.ContinueWith(t =>
{
foreach (var stock in t.Result.Take(5))
{
stocks.Add(stock);
}
GuiDelegate del = delegate
{
dataGridView1.DataSource = stocks.Select(p => new { value = $"{p.Ticker} {p.Volume}" }).ToList();
dataGridView1.Columns[0].Width = dataGridView1.Width;
};
dataGridView1.Invoke(del);
return(t.Result);
});
tickerLoadingTasks.Add(loadedLines);
}
var allLoadingTasks = Task.WhenAll(tickerLoadingTasks);
await allLoadingTasks;
}
catch (Exception ex)
{
textBox1.Text = ex.Message;
}
finally
{
cancellationTokenSource = null;
}
btnOneByOne.Text = "9 One By One";
}
