private static WeakEvent FindRegistration(object source, string eventName)
{
// Look for registration
WeakEvent reg = null;
for (var iReg = Registrations.Count - 1; iReg >= 0; iReg--)
{
// Get the registration
reg = Registrations[iReg];
// If the source is dead, remove the registration
if ((reg != null) && (!reg.Source.IsAlive))
{
Registrations.RemoveAt(iReg);
reg = null;
}
// If it's the right source, done searching
if (reg != null && ((reg.Source.Target == source) && (reg._eventName == eventName)))
{
break;
}
reg = null;
}
// Done searching
return(reg);
}
/// <summary>
/// Adds a weak subscription to the specified handler.
/// </summary>
/// <param name="source">
/// The object that is the source of the event.
/// </param>
/// <param name="eventName">
/// The name of the event.
/// </param>
/// <param name="handler">
/// The handler to subscribe.
/// </param>
public static void Subscribe <THandler>(object source, string eventName, THandler handler) where THandler : class
{
// Verify delegate type
VerifyDelegate <THandler>();
// Try to find existing
var reg = FindRegistration(source, eventName);
// If not found, create one and store it
if (reg == null)
{
reg = new WeakEvent(source, eventName);
Registrations.Add(reg);
}
// Add the subscription
reg.Subscribe(handler as Delegate);
}