xamarin/Xamarin.Forms

HasUnevenRows fires ItemAppearing for invisible screen items when the cell is an Image

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#3,874 创建于 2018年9月22日

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a/listviewe/5 :clock5:help wantedinactivep/Androidt/bug :bug:up-for-grabs

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描述

Description

If a ListView has cells that are made up of only Image instances (or wrapper layouts whose only content is an Image) and HasUnevenRows is set to true, then ItemAppearing will be fired for virtually every list item even if it does not appear on the screen. This is bad for scenarios involving infinite scrolling. The issue seems to exist on both Android and iOS.

Ref: an old issue (27845) that's been resolved.

Steps to Reproduce

  1. Run the attached repro
  2. Observe that ItemAppearing is fired for dozens of items even though it should be fired only a few times upon page load

Reproduction Link

App2.zip

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