Show code snippet - Using a QWeakReferenceCollection

//A QWeakReferenceCollection containing QWeakReferences to QColorSchemes
public class QColorSchemeCollection : QWeakReferenceCollection
{
	//Default constructor
	public QColorSchemeCollection()
	{}

	//Adds a QWeakReference to the QColorScheme to the collection
	public void AddColorScheme(QColorScheme colorScheme)
	{
		this.AddObject(colorScheme);
	}

	//Removes the QWeakReference of the QColorScheme from the collection
	public void RemoveColorScheme(QColorScheme colorScheme)
	{
		this.RemoveObject(colorScheme, true);
	}

	//Raises the ColorsChanged event of 
	//all QColorSchemes in the collection
	public void RaiseColorsChanged()
	{
		//iterate backwards because we remove
		//collected weak references
		QColorScheme tmp_oColorScheme;
		for (int i = this.Count - 1; i >= 0; i--)
		{
			//get the weak reference
			QWeakReference tmp_oReference = this[i];
			if ((tmp_oReference != null) &&
			    (!tmp_oReference.Finalized) &&
			    (tmp_oReference.IsAlive))
			{
				//raise the event if the
				//reference is still alive
				tmp_oColorScheme = (QColorScheme)
					tmp_oReference.Target
				tmp_oColorScheme.RaiseColorsChanged();
			}
			else
			{
				//remove the item if the
				//colorscheme is collected
				this.RemoveAt(i);
			}
		}
	}
}