protected static void PrepareDCObject(DelayedCall dc, int milliseconds, bool async) {
if (milliseconds < 0) {
throw new ArgumentOutOfRangeException("milliseconds", "The new timeout must be 0 or greater.");
}
// Get the current synchronization context if required, with dummy fallback
dc.context = null;
if (!async) {
dc.context = SynchronizationContext.Current;
if (dc.context == null)
throw new InvalidOperationException("Cannot delay calls synchronously on a non-UI thread. Use the *Async methods instead.");
}
if (dc.context == null) dc.context = new SynchronizationContext(); // Run asynchronously silently
dc.timer = new System.Timers.Timer();
if (milliseconds > 0) dc.timer.Interval = milliseconds;
dc.timer.AutoReset = false;
dc.timer.Elapsed += dc.Timer_Elapsed;
Register(dc);
}
protected static void Unregister(DelayedCall dc) {
lock (dcList) {
// Free a reference on this object to allow the Garbage Collector to dispose it
// if no other reference is kept to it
dcList.Remove(dc);
}
}
/// <summary>
/// Creates a new asynchronous <c>DelayedCall</c> instance. The callback function will be invoked on a <c>ThreadPool</c> thread.
/// </summary>
/// <param name="cb">Callback function</param>
/// <param name="milliseconds">Time to callback invocation</param>
/// <returns>Newly created <c>DelayedCall</c> instance that can be used for later controlling of the invocation process</returns>
public static DelayedCall CreateAsync(Callback cb, int milliseconds) {
DelayedCall dc = new DelayedCall();
PrepareDCObject(dc, milliseconds, true);
dc.callback = cb;
return dc;
}
protected static void Register(DelayedCall dc) {
lock (dcList) {
// Keep a reference on this object to prevent it from being caught by the Garbage Collector
if (!dcList.Contains(dc))
dcList.Add(dc);
}
}