Bug 33530 - ListView.ItemTapped event is not fired in iOS if UITableView.Scrolled event is subscribed
Summary: ListView.ItemTapped event is not fired in iOS if UITableView.Scrolled event i...
Alias: None
Product: Forms
Classification: Xamarin
Component: iOS ()
Version: 1.5.0
Hardware: Macintosh Mac OS
: Normal normal
Target Milestone: ---
Assignee: Bugzilla
Depends on:
Reported: 2015-09-01 06:34 UTC by ondrej.kanecka
Modified: 2015-09-30 06:18 UTC (History)
2 users (show)

Tags: ac
Is this bug a regression?: ---
Last known good build:

Xamarin Studio simple project (6.90 MB, application/zip)
2015-09-01 06:34 UTC, ondrej.kanecka

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Description ondrej.kanecka 2015-09-01 06:34:10 UTC
Created attachment 12700 [details]
Xamarin Studio simple project

Create a iOS custom renderer for Xamarin.Forms.ListView that inherits from ListViewRenderer class. Inside the method OnElementChanged subscribe for event Scrolled (or similar events like DraggingEnded or DecelerationEnded) of the Control (the Control is of type UITableView). There is an event in Xamarin.Forms.ListView called ItemTapped. This event is no longer fired due to Scrolled event subscription in the custom renderer.
Simple project is attached that demonstrates this behavior.
Comment 1 Rui Marinho 2015-09-30 06:18:08 UTC
Hi, this isn't a bug , when you try run the sample you get this exception:

"Event registration is overwriting existing delegate. Either just use events or your own delegate: Xamarin.Forms.Platform.iOS.ListViewRenderer+ListViewDataSource UIKit.UIScrollView+_UIScrollViewDelegate"

What's happening is Xamarin.Forms ListViewRenderer is setting a DataSource to the UITablewView that has it's own UISCrollViewDelegate, this means you can't subscribe to the Scrolled event since there's already a delegate.