private ArrayList BuildPrimeNumberList(int numberToTest, AsyncOperation asyncOp)
{
ProgressChangedEventArgs e = null;
var primes = new ArrayList();
var firstDivisor = 1;
var n = 5;
primes.Add(2);
primes.Add(3);
while (n < numberToTest && !IsTaskCanceled(asyncOp.UserSuppliedState))
{
if (IsPrime(primes, n, out firstDivisor))
{
var progressPercentage = (int)((float)n / (float)numberToTest * 100);
e = new CalculatePrimeProgressChangedEventArgs(n, progressPercentage, asyncOp.UserSuppliedState);
asyncOp.Post(onProgressReportDelegate, e);
primes.Add(n);
// Yield the rest of this time slice.
Thread.Sleep(0);
}
// Skip even numbers.
n += 2;
}
return(primes);
}
// This event handler updates the ListView control when the
// PrimeNumberCalculator raises the ProgressChanged event.
//
// On fast computers, the PrimeNumberCalculator can raise many
// successive ProgressChanged events, so the user interface
// may be flooded with messages. To prevent the user interface
// from hanging, progress is only reported at intervals.
private void primeNumberCalculator1_ProgressChanged(ProgressChangedEventArgs e)
{
if ((this.progressCounter++ % this.progressInterval) == 0)
{
Guid taskId = (Guid)e.UserState;
if (e is CalculatePrimeProgressChangedEventArgs)
{
CalculatePrimeProgressChangedEventArgs cppcea =
e as CalculatePrimeProgressChangedEventArgs;
this.UpdateListViewItem(taskId, cppcea.ProgressPercentage, cppcea.LatestPrimeNumberValue);
}
else
{
this.UpdateListViewItem(taskId, e.ProgressPercentage);
}
}
else if (this.progressCounter > this.progressInterval)
{
this.progressCounter = 0;
}
}
