Delegate and asynchronous call ...........

Using System;

Public   Delegate   Int Asyncmethod ( Int Start, Int End ); // Declare a delegate

Public   Class Asyncdemo
{
Public   Static   Void Main ()
{
Asyncmethod async =   New Asyncmethod (dosum ); // Instantiate delegate
Iasyncresult result = Async. begininvoke ( 1 , 100000 ); // Start asynchronous call
Console. writeline ( " Start working. " + Datetime. Now. tostring ( " Yyyy-mm-dd hh: mm: SS " ));
Int Sum = Async. endinvoke (result ); // Stop end asynchronous call
Console. writeline ( " The result is: "   + Sum );
Console. writeline ( " The work is over. "   + Datetime. Now. tostring ( " Yyyy-mm-dd hh: mm: SS " ));
}

Public   Static   Int Dosum ( Int Start, Int End)
{
Int Result =   0 ;
For ( Int I = Start; I < End; I ++ )
{
Result + = I;
}
Return Result;
}
}