New features and controls in Xamarin Forms 4.3 and 4.4, including CollectionView, RefreshView, CarouselView, IndicatorView and SwipeView. Associated code is here: https://github.com/AlecDTucker/MonkeyFestAustralia2020

1. Xamarin Forms 4+
Alec Tucker
alec@obiquitech.com
ObiquiTech App Studio

2. Agenda
• What’s New
• CollectionView
• RefreshView
• CarouselView
• IndicatorView
• SwipeView
• Community Contributions

3. CollectionView
• Horizontal scrolling
• Simpler visual tree => simpler code – no more cells
• EmptyView, EmptyViewTemplate
• No RowHeight or HasUnevenRows  Use ItemSizingStrategy
• Perf Tip: Use MeasureFirstItem if all cells are the same size
• No built in separators
• Use a BoxView in your ItemTemplate

4. CollectionView
• Infinite scrolling with RemainingItemsThresholdReachedCommand
• If RemainingItemsThreshold = 0, this command will execute as the user reaches the
bottom of the list
• Set RemainingItemsThreshold to a positive number to execute the command when
there are that many items left to scroll
• Snap into position using SnapPointsType and SnapPointsAlignment
• SnapPointsType.None, .Mandatory, .MandatorySingle
• SnapPointsAlignment.Start, .Center, .End
• Multiple layouts
• Vertical / Horizontal List
• Vertical / Horizontal Grid
• No direct support for PullToRefresh...

5. Demo

6. RefreshView
• Wrap your CollectionViews in one of these
• IsRefreshing, Command

7. Demo

8. CarouselView
• Long missing from Xamarin Forms
• Multiple third party attempts
• Rebuilt based on CollectionView
• Improved performance
• Swipe between items
• Also has EmptyView

9. IndicatorView
• IndicatorSize
• IndicatorColor
• SelectedIndicatorColor
• Link to CarouselView with IndicatorView.ItemsSourceBy
- That’s it. The rest is done for you!

10. Demo

11. SwipeView
• Add ‘context items’ to any control
• Left or Right
• Top or Bottom

12. Demo

13. Other Nuggets
• Editor
• IsTextPredictionEnabled
• More fast renderers
• Label
• TextType – supports html
• Image
• Gif support

14. Community Contributions
• Contributions from 34 devs, including
• Placeholder text alignment
• Letter spacing
• Multiple fixes for UWP, Tizen, WPF
• Also keep an eye out for Peter Foot’s MediaViewer control
• Embedded video, audio

15. Contact Details
Alec Tucker
alec@obiquitech.com
ObiquiTech App Studio