//method that receives a callback when the results are available
void ResultsReady(IAsyncResult result)
{
List <string> keys_matched = new List <string>();
// Extract the delegate from the
// System.Runtime.Remoting.Messaging.AsyncResult.
GetResultsDelegate getResultDelegate = (GetResultsDelegate)((AsyncResult)result).AsyncDelegate;
int g = (int)result.AsyncState;
// Obtain the result
bool return_val = getResultDelegate.EndInvoke(ref keys_matched, result);
waiter.Set();
}
//Method2: asynchronous pattern using a BeginInvoke, followed by waiting with a time-out
public void GetResultsAndWait(string key, ref List <string> keys_matched, int waitTime = 10000)
{
//declare instance of delegate
GetResultsDelegate getResultDelegate = new GetResultsDelegate(ResultsGetter.GetResults);
//asynchonously invoke the GetResult method
IAsyncResult result = getResultDelegate.BeginInvoke(key, ref keys_matched, null, null);
while (!result.IsCompleted)
{
//do any work that can done before waiting
result.AsyncWaitHandle.WaitOne(waitTime, false);
}
result.AsyncWaitHandle.Close();
//the asynchronous operation has completed
bool return_val = getResultDelegate.EndInvoke(ref keys_matched, result);
}