public void addChild(Child child)
{
if (DataSource.childList.Exists(c => c.idChild == child.idChild))//no child found
{
throw new Exception("Child is already exist in system");
}
DataSource.childList.Add(child.duplicate());
}
public void updateChild(Child child)
{
int index = DataSource.childList.FindIndex(c => c.idChild == child.idChild);
if (index == -1)//no child found
{
throw new Exception("Child is not appear in system");
}
DataSource.childList[index] = child.duplicate();
}