Bug 36681 - [FormsApplicationActivity] NRE When Replacing CurrentPage's Content When Picker is Unfocused
Summary: [FormsApplicationActivity] NRE When Replacing CurrentPage's Content When Pick...
Status: RESOLVED FIXED
Alias: None
Product: Forms
Classification: Xamarin
Component: Android ()
Version: 2.0.0
Hardware: PC Mac OS
: Normal major
Target Milestone: ---
Assignee: Samantha Houts [MSFT]
URL:
Depends on:
Blocks:
 
Reported: 2015-12-07 17:17 UTC by Jimmy [MSFT]
Modified: 2017-09-12 11:57 UTC (History)
6 users (show)

Tags: ac android picker FormsApplicationActivity, retest, fr
Is this bug a regression?: Yes
Last known good build: 2.3.1.114


Attachments
repro project (60.66 KB, application/zip)
2015-12-07 17:17 UTC, Jimmy [MSFT]
Details


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Status:
RESOLVED FIXED

Description Jimmy [MSFT] 2015-12-07 17:17:39 UTC
Created attachment 14149 [details]
repro project

### Overview
When trying to replace an entire page’s content after making a Picker selection, a NullReferenceException is thrown.

In the attached repro project, the current page’s content is being replaced when Picker.Unfocused is fired. This works on iOS, but an exception is thrown on Android.


### Steps to Reproduce
1. Run attach Android project
2. Select an item from the Picker


### Expected Results
After selecting an item, the tab page’s content will be replaced.


### Actual Results
A NullReferenceException is thrown as the Picker is closed.


### Environment Info
=== Xamarin Studio ===

Version 5.10.1 (build 3)
Installation UUID: 94ce5106-6a72-4691-b34e-cd5857b1db66
Runtime:
	Mono 4.2.1 (explicit/6dd2d0d)
	GTK+ 2.24.23 (Raleigh theme)

	Package version: 402010102

=== Xamarin.Profiler ===

Version: 0.24.0.0
Location: /Applications/Xamarin Profiler.app/Contents/MacOS/Xamarin Profiler

=== Apple Developer Tools ===

Xcode 7.1.1 (9081)
Build 7B1005

=== Xamarin.iOS ===

Version: 9.2.1.54 (Business Edition)
Hash: eb4c1ef
Branch: master
Build date: 2015-12-01 02:12:30-0500

=== Xamarin.Mac ===

Version: 2.4.0.109 (Business Edition)

=== Xamarin.Android ===

Version: 6.0.0.34 (Business Edition)
Android SDK: /Users/jimmygarrido/Library/Developer/Xamarin/android-sdk-macosx
	Supported Android versions:
		2.3   (API level 10)
		4.0.3 (API level 15)
		4.1   (API level 16)
		4.4   (API level 19)
		5.0   (API level 21)
		5.1   (API level 22)
		6.0   (API level 23)

SDK Tools Version: 24.4.1
SDK Platform Tools Version: 23.0.1
SDK Build Tools Version: 22.0.1

Java SDK: /usr
java version "1.7.0_79"
Java(TM) SE Runtime Environment (build 1.7.0_79-b15)
Java HotSpot(TM) 64-Bit Server VM (build 24.79-b02, mixed mode)

=== Xamarin Android Player ===

Version: 0.6.5
Location: /Applications/Xamarin Android Player.app

=== Build Information ===

Release ID: 510010003
Git revision: f2021a209d66d49cbc0649a6d968b29040e57807
Build date: 2015-12-01 10:43:40-05
Xamarin addins: dfd4f5103e8951edbc8ac24480b53b53c55e04ff
Build lane: monodevelop-lion-cycle6-baseline

=== Operating System ===

Mac OS X 10.11.1
Darwin Jimmys-MacBook-Pro.local 15.0.0 Darwin Kernel Version 15.0.0
    Sat Sep 19 15:53:46 PDT 2015
    root:xnu-3247.10.11~1/RELEASE_X86_64 x86_64
Comment 1 Jimmy [MSFT] 2015-12-07 17:19:50 UTC
Stack trace: https://gist.github.com/jimmgarrido/7f8f7a7b2590e68772c8
Comment 2 Samantha Houts [MSFT] 2016-03-30 23:15:11 UTC
This has been fixed in a recent version. Thanks!
Comment 4 Jimmy [MSFT] 2017-08-15 00:39:06 UTC
Confirming that this has regressed in recent versions. I've updated the original gist with the new stack trace: https://gist.github.com/jimmgarrido/7f8f7a7b2590e68772c8

This only happens when using FormsApplicationActvity. It works without issue when using FormsAppCompatActivity which is the recommended approach now.


### Version Tests
2.3.6.127   BAD
2.3.5-pre6  BAD
Comment 6 Jimmy [MSFT] 2017-09-08 17:42:25 UTC
This broke in 2.3.2.127 as a result of the fix for bug 42687. 

Created PR for new fix:  https://github.com/xamarin/Xamarin.Forms/pull/1132
Comment 7 Rui Marinho 2017-09-12 11:57:05 UTC
Should be fixed on 2.4.1-pre1