Carousel control crashes on addition without initial items

Describe the bug The carousel control crashes when it has no items initially and one adds items afterwards.

To Reproduce

1. Add a carousel without any initial items
2. Add an item (e.g. via code) once the view has been initialised.
3. Crashes with an Out-of-bounds exception

Expected behavior No crash.

Additional context Debugging shows that Carousel.UpdateItemsPosition() is crashing once it tries to use the PageIndex, which is -1 at that point and therefore of course out-of-bounds.

Possible fix is to update the PageIndex to an in-bounds range value when an item is added.

private void UpdateItemsPosition()
{
    if (!CheckNull() || !_appliedTemplate || Items.Count == 0)
        return;

    if (PageIndex == -1) // Fixes the crash
    {
         PageIndex = 0;
    }

[SamirKharchi]

Hi guys!

sorry for the delay (had tons of work crashing on me after holidays, then it slipped my mind). I had the time yesterday to strip down our crashing code base and once I have stripped it down, the crash is not reproducable anymore I’m afraid. However, in our full blown code it still does crash. It might be a threading issue on our side or something to do with Prism (which we are using) I guess, because I cannot reproduce it on a clean project or the demo project of HandyControl either.

I keep it in our version of HandyControl but it probably is not a necessary fix. So rry for keeping this pending for so long.

[ghost1372]

@SamirKharchi Are you back?😅