Question

(Note: I know there’s a related Q+A, but it relates to the timer ending, whereas mine is to do with ticks)

This code is used to animate a rectangle moving between 2 points. At the moment, the first movement is perfect, but each time after that the animation becomes significantly faster and faster each time it is called.

I’m thinking it’s due to a misunderstanding on my part on how to call a rectangle movement on each tick.

Any help would be greatly appreciated!

This section starts the timer:

        if (floorNo == 2)
        {
            timerDown.Tick += new EventHandler(timer_LiftDown);
            timerDown.Interval = 10;
            timerDown.Enabled = true;
            timerDown.Start();
        }

This code is called on each tick (right?):

    void timer_LiftDown(object sender, EventArgs e)
    {
        rectangle1.Location = new Point(192, rectangle1.Location.Y + 2);
        if (rectangle1.Location.Y >= 196)
        {
            timerDown.Stop();
        }
    }

I’ve cut out some unrelated code (e.g updating textboxes with current state, changing floorNo variable etc).

Thank you.

Answer 1

Instead of subscribing and unsubscribing to the event each time, I would suggest setting up the timer once, and then just calling start/stop on it.

//Somewhere in a load event...
timerDown.Tick += new EventHandler(timer_LiftDown);
timerDown.Interval = 10;
timerDown.Enabled = true;

//More code...

if (floorNo == 2)
{
    timerDown.Start();
}

//More code...

void timer_LiftDown(object sender, EventArgs e)
{
    rectangle1.Location = new Point(192, rectangle1.Location.Y + 2);
    if (rectangle1.Location.Y >= 196)
    {
        timerDown.Stop();
    }
}

That way, you only have to initialize the timer and set the interval once, and can start/stop at will.