How to make sure MouseEnter fires for all elements - wpf

Question

I have a WPF ItemsControl displaying a series of Rectangles.
Each rectangle makes use of MVVM Lights EventToCommand to track the MouseEnter event and set the Rectangle to 'Selected'
I then use this property to highlight the rectangle using triggers in the style.
My problem occurs if the mouse is dragged too quickly.
Working (Slowly dragged):
Not working (quickly dragged):
In this case the event has not fired for the second Rectangle.
How do I make sure the event fires for all controls the mouse moves over?

Answer 1

My suggestion would be to put all the event occurences in a queue. I think your problem occures because when an event fires, you call one method and if the method hasn't finished at the time the next event occurs, it can not be called a second time.
Create a queue and put the event occures in there, then create a thread that waits for the queue to fill and then procceses it it.
Sample:
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
namespace ConsoleApplication3
{
using System.Timers;
using Timer = System.Timers.Timer;
class Program
{
private static Queue<My_Event> EventQueue;
private static Timer t = new Timer(10);
static void Main(string[] args)
{
Task thread = new Task(MarkStuffYellow);
EventQueue = new Queue<My_Event>();
t.Elapsed += t_Elapsed;
t.Start();
t.AutoReset = true;
}
static void t_Elapsed(object sender, ElapsedEventArgs e)
{
EventQueue.Enqueue(new My_Event(sender, e));
}
private static void MarkStuffYellow()
{
/// !!! While (true) is not an solution, if you do it like this,
/// your CPU will be full !!!
while (true)
{
if (EventQueue.Any())
{
My_Event myEvent = EventQueue.Dequeue();
var sender = myEvent.Sender;
var e = myEvent.E;
/// Do Stuff with your event
}
}
}
}
/// Needed to save your event
internal class My_Event
{
public My_Event(object sender, ElapsedEventArgs e)
{
this.Sender = sender;
this.E = e;
}
public object Sender;
public ElapsedEventArgs E;
}
}