WPF: Storyboard loop object owned by another thread - wpf

Question

Hi all my simple code looks like this
private void flipForeverever(object sender, EventArgs args)
{
moveYs = new DoubleAnimation();
m2oveYs = new DoubleAnimation();
try
{
sf.Remove(this);
sf.Children.Clear();
}
catch (Exception e)
{
}
if (firstPanelAngle == 360)
{
moveYs.To = 180;
moveYs.From = 0;
}
else
{
moveYs.To = 360;
moveYs.From = 180;
}
if (secondPanelAngle == 360)
{
m2oveYs.To = 180;
m2oveYs.From = 0;
}
else
{
m2oveYs.To = 360;
m2oveYs.From = 180;
}
sf = (Storyboard)FindResource("Storyboard1");
Storyboard.SetTargetName(moveYs, "rotatePanel");
Storyboard.SetTargetProperty(moveYs, new thisPropertyPath(AxisAngleRotation3D.AngleProperty));
Storyboard.SetTargetName(m2oveYs, "rotateSecond");
Storyboard.SetTargetProperty(m2oveYs, new PropertyPath(AxisAngleRotation3D.AngleProperty));
sf.Children.Add(moveYs);
sf.Children.Add(m2oveYs);
// sf.RepeatBehavior = RepeatBehavior.Forever;
if (flipForever)
{
sf.Completed += new EventHandler(delaythespin);
sf.Begin(this);
}
}
private void delaythespin(object sender, EventArgs args)
{
sf.Stop(this);
System.Timers.Timer timer = new System.Timers.Timer(500);
timer.Elapsed += new System.Timers.ElapsedEventHandler(flipForeverever);
timer.Enabled = true;
firstPanelAngle = rotatePanel.Angle;
secondPanelAngle = rotateSecond.Angle;
timer.Start();
}
So basically i call flipForeverever through a click call and it is supposed to loop forever until i set flipforever to false... But then it is giving me this error...
The calling thread cannot access this object because a different thread owns it.
Any help will really be appreciated

Answer 1

It sounds like you might be having thread affinity problems. Have you tried using a DispatcherTimer instead of a System.Timers.Timer?
private DispatcherTimer _timer;
private void GoButton_Click(object sender, RoutedEventArgs e)
{
_timer = new DispatcherTimer(); // create timer
_timer.Interval = new TimeSpan(0, 0, 1); // tick every 1s
_timer.Tick += new EventHandler(_timer_Tick); // method to call
_timer.Start(); // start timer
}
void _timer_Tick(object sender, EventArgs e)
{
// we should be on the correct thread now
GoButton.Background = Brushes.Aqua;
}
Or, if you need to use System.Timers.Timer, use Invoke or BeginInvoke to get on the correct thread after the timer fires?
private System.Timers.Timer _timer;
private void GoButton_Click(object sender, RoutedEventArgs e)
{
_timer = new System.Timers.Timer(1000);
_timer.Elapsed += new System.Timers.ElapsedEventHandler(_timer_Elapsed);
_timer.Start();
}
void _timer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
{
// use Dispatcher.Invoke on the UI object that you want to modify
// to get on the correct thread for that UI object
GoButton.Dispatcher.Invoke((ThreadStart)(() =>
{
GoButton.Background = Brushes.Aqua;
}));
}