public void SlowDownBecauseOfPropertyChangeEventsShouldBeSmall()
{
var parentObject = new ParentObject();
var strings = new string[1000000]; // pre-cache strings to have less timing variance
for (var i = 0; i < 1000000; i++)
{
parentObject.Children.Add(new ChildObject());
strings[i] = i.ToString();
}
// without property changed
var children = parentObject.Children;
var t = DateTime.Now;
for (int i = 0; i < 10; i++)
{
ChangeChildrenWithoutEvents(children, strings);
}
var dtWithoutPropertyChanged = (DateTime.Now - t).TotalMilliseconds;
// with property changed
t = DateTime.Now;
for (int i = 0; i < 10; i++)
{
ChangeChildrenWithEvents(children, strings);
}
var dtWithPropertyChanged = (DateTime.Now - t).TotalMilliseconds;
log.InfoFormat("1000 changes without NotifyPropertyChanged: {0} milliseconds", dtWithoutPropertyChanged);
log.InfoFormat("1000 changes with NotifyPropertyChanged: {0} milliseconds", dtWithPropertyChanged);
var percentsSlower = (dtWithPropertyChanged / dtWithoutPropertyChanged - 1.0) * 100;
log.InfoFormat("{0:0.000000}% slower", percentsSlower);
Assert.LessOrEqual(percentsSlower, 600); // it is still buggy, measured time variaes a lot
}
public void EventBubblingChildObjectInAList()
{
//same situation but now with a child in a list
ParentObject parent = new ParentObject();
int changeCount = 0;
//add the child in a list
ChildObject child = new ChildObject();
parent.Children.Add(child);
Post.Cast<ParentObject, INotifyPropertyChanged>(parent).PropertyChanged +=
delegate(object sender, PropertyChangedEventArgs e)
{
Assert.AreEqual("Name", e.PropertyName);
changeCount++;
};
child.Name = "newName";
Assert.AreEqual(1, changeCount);
}
public void SkipNotificationForSelectedProperty()
{
ParentObject parentObject = new ParentObject();
ChildObject childObject = new ChildObject();
parentObject.Child = childObject;
int changeCount = 0;
Post.Cast<ParentObject, INotifyPropertyChanged>(parentObject).PropertyChanged +=
delegate(object sender, System.ComponentModel.PropertyChangedEventArgs e)
{
Assert.AreEqual("Name", e.PropertyName);
changeCount++;
};
childObject.Parent = parentObject;
Assert.AreEqual(0, changeCount);
childObject.Name = "newName";
Assert.AreEqual(1, changeCount);
}
public void EventBubblingChildObject()
{
ParentObject parent = new ParentObject();
int changeCount = 0;
ChildObject child = new ChildObject();
parent.Child = child;
Post.Cast<ParentObject, INotifyPropertyChanged>(parent).PropertyChanged +=
delegate(object sender, PropertyChangedEventArgs e)
{
Assert.AreEqual("Name", e.PropertyName);
changeCount++;
};
child.Name = "newName";
Assert.AreEqual(1, changeCount);
}