Question

I try to draw something on canvas every 1 second .Then, I create a thread to call a method to draw after sleep 1 second. The problem is calling Canvas object to draw. The program tell me error message

The calling thread cannot access this object because a different thread owns it.

Code

private void drawTimeTick() {
        ...
        Thread iThread = new Thread(new ThreadStart(tickThread));
        iThread.Start();
    }
    private void tickThread(){
        try
        {
            Thread.Sleep(1000);
            ...
            Canvas.SetLeft(tick, 700);
            Canvas.SetTop(tick, 30);
        }catch(Exception ex){
            MessageBox.Show("Exception tickThread : "+ex.Message);
        }
    }

How to access Canvas in Thread to draw?

Answer 1

Have a look at the DispatcherTimer class. It is designed for exactly this scenario, as can be seen in the MSDN examples.