When changing page by tapping on IOs PageControl speedily, the current indicator moves ahead of the page

Question

In my Xamarin.IOs project, I have a UIPageControl that is combined with a Paging enabled UICollectionView.

I use the CardPageControl.PrimaryActionTriggered event to handle swiping the page.

CardPageControl.PrimaryActionTriggered += OnPageControlTapped;

private async void OnPageControlTapped(object sender, EventArgs e)
{
    // SetContentOffset of the collection view
}

But when I speedily tap on the PageControl, the current indicator moves way ahead of the current page and then after the tapping ended, the current indicator re-positions in the correct indicator.

How can I fix this?

Answer 1

You have to enable DefersCurrentPageDisplay. This is false by default.

CardPageControl.DefersCurrentPageDisplay = true;

Then inside OnPageControlTapped, invoke UpdateCurrentPageDisplay() of CardPageControl,

private async void OnPageControlTapped(object sender, EventArgs e)
{
    // SetContentOffset of the collection view

    CardPageControl.UpdateCurrentPageDisplay();
}

This will sync the PageControl current indicator with the current page.