/// <summary>
/// Execution entry point.
/// </summary>
public static void Main()
{
// Create an instance of a type that offers an event.
TypeWithWeakDelegateEvent twwde = new TypeWithWeakDelegateEvent();
// Create an instance of a type that will register with the event.
s_someType = new SomeType();
// Register this object's SomeEventGotRaised method with our the other
// object's event.
twwde.SomeEvent += s_someType.SomeEventGotRaised;
// Raising the event calls through the delegate.
twwde.RaiseSomeEvent("Before GC; this appears");
// As long as a strong reference to the SomeType object exists, it will
// not be collected, and every call to RaiseSomeEvent will call the
// SomeType object's SomeEventGotRaised method.
// However, if no strong reference to the SomeType object exists and
// garbage collection occurs, future calls to RaiseSomeEvent will NOT
// call the SomeType object's SomeEventGotRaised method, because the
// object no longer exists in memory. No exception is raised, because
// that is not an error condition.
// To demonstrate this, set s_someType to null and force garbage
// collection to occur.
s_someType = null;
Debug.GC(true);
// Now the SomeType object no longer exists. Raising an event will not
// produce output.
twwde.RaiseSomeEvent("After GC; this doesn't appear");
Debug.Print("Program ending");
}
/// <summary>
/// Execution entry point.
/// </summary>
public static void Main()
{
// Create an instance of a type that offers an event.
TypeWithWeakDelegateEvent twwde = new TypeWithWeakDelegateEvent();
// Create an instance of a type that will register with the event.
s_someType = new SomeType();
// Register this object's SomeEventGotRaised method with our the other
// object's event.
twwde.SomeEvent += s_someType.SomeEventGotRaised;
// Raising the event calls through the delegate.
twwde.RaiseSomeEvent("Before GC; this appears");
// As long as a strong reference to the SomeType object exists, it will
// not be collected, and every call to RaiseSomeEvent will call the
// SomeType object's SomeEventGotRaised method.
// However, if no strong reference to the SomeType object exists and
// garbage collection occurs, future calls to RaiseSomeEvent will NOT
// call the SomeType object's SomeEventGotRaised method, because the
// object no longer exists in memory. No exception is raised, because
// that is not an error condition.
// To demonstrate this, set s_someType to null and force garbage
// collection to occur.
s_someType = null;
Debug.GC(true);
// Now the SomeType object no longer exists. Raising an event will not
// produce output.
twwde.RaiseSomeEvent("After GC; this doesn't appear");
Debug.Print("Program ending");
}