Pre-release: Xamarin.Forms 2.4.0.275-pre3

DavidOrtinau

@MichaelRumpler you're right. We're going to do basically what you've done for now so we aren't breaking anyone, and we'll reconsider removing it in a future release once libraries have a chance to refactor.

Would you like to kindly submit a PR for that?

AlessandroCaliaro

@MichaelRumpler for President

MichaelRumpler

@DavidOrtinau said:
@MichaelRumpler you're right. We're going to do basically what you've done for now so we aren't breaking anyone, and we'll reconsider removing it in a future release once libraries have a chance to refactor.

Would you like to kindly submit a PR for that?

I just wanted to, submitted a bug but then I saw that @EZHart already created the PR. So I won't continue with the PR for now.

batmaci

When using masterdetail page, if I minimize or screen lock and come back to app, OnAppearing method of All pages on the stack are executed in Android. is this not a bug? Is this how it supposed to work in Android?

MichaelRumpler

The next problem I found in XF 2.4.0.266-pre1 is with the Android status bar. I usually set it to a dark orange and the icons should be white:

That worked in 2.3.4 and also when I installed 2.3.5.256-pre6.

But after I updated to 2.4.0.266-pre1 the status bar was all white.

I filed bug 58972 for this.

I'm not very familiar with Android themes, so I may have done something wrong which accidentally worked. If so, then please tell me what I should change. However it did work before and now it doesn't.

LGMaestrelli

I'm getting this error on iOS:

Error while resolving expression: One or more errors occurred.
2017-08-23 10:53:59.340 UseallUseallUseAppiOS[864:600317] Unhandled managed exception:
Object reference not set to an instance of an object (System.NullReferenceException)
  at Xamarin.Forms.Platform.iOS.EventTracker.LoadRecognizers () [0x0005d] in C:\BuildAgent3\work\ca3766cfc22354a1\Xamarin.Forms.Platform.iOS\EventTracker.cs:347 
  at Xamarin.Forms.Platform.iOS.EventTracker.OnElementChanged (System.Object sender, Xamarin.Forms.Platform.iOS.VisualElementChangedEventArgs e) [0x0004e] in C:\BuildAgent3\work\ca3766cfc22354a1\Xamarin.Forms.Platform.iOS\EventTracker.cs:413 
  at Xamarin.Forms.Platform.iOS.VisualElementRenderer`1[TElement].OnElementChanged (Xamarin.Forms.Platform.iOS.ElementChangedEventArgs`1[TElement] e) [0x0002c] in <c463a321fcd64d278aaac72489be2413>:0 
  at Xamarin.Forms.Platform.iOS.ViewRenderer`2[TView,TNativeView].OnElementChanged (Xamarin.Forms.Platform.iOS.ElementChangedEventArgs`1[TElement] e) [0x00000] in <c463a321fcd64d278aaac72489be2413>:0 
  at Xamarin.Forms.Platform.iOS.ImageRenderer
.<>n__0 (Xamarin.Forms.Platform.iOS.ElementChangedEventArgs`1[TElement] e) <0x1017cb4a0 + 0x00043> in <c463a321fcd64d278aaac72489be2413#3141dfb56d2894e611949b4ad4d06789>:0 
  at Xamarin.Forms.Platform.iOS.ImageRenderer+<OnElementChanged>d__2.MoveNext () [0x000d6] in C:\BuildAgent3\work\ca3766cfc22354a1\Xamarin.Forms.Platform.iOS\Renderers\ImageRenderer.cs:70 
--- End of stack trace from previous location where exception was thrown ---
  at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /Library/Frameworks/Xamarin.iOS.framework/Versions/10.12.0.18/src/mono/mcs/class/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:151 
  at System.Runtime.CompilerServices.AsyncMethodBuilderCore+<>c.<ThrowAsync>b__6_0 (System.Object state) [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/10.12.0.18/src/mono/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/AsyncMethodBuilder.cs:1018 
  at UIKit.UIKitSynchronizationContext+<Post>c__
AnonStorey0.<>m__0 () [0x00000] in /Users/builder/data/lanes/4991/4a279c9a/source/xamarin-macios/src/UIKit/UIKitSynchronizationContext.cs:24 
  at Foundation.NSAsyncActionDispatcher.Apply () [0x00000] in /Users/builder/data/lanes/4991/4a279c9a/source/xamarin-macios/src/Foundation/NSAction.cs:163 
  at (wrapper managed-to-native) UIKit.UIApplication:UIApplicationMain (int,string[],intptr,intptr)
  at UIKit.UIApplication.Main (System.String[] args, System.IntPtr principal, System.IntPtr delegate) [0x00005] in /Users/builder/data/lanes/4991/4a279c9a/source/xamarin-macios/src/UIKit/UIApplication.cs:79 
  at UIKit.UIApplication.Main (System.String[] args, System.String principalClassName, System.String delegateClassName) [0x00038] in /Users/builder/data/lanes/4991/4a279c9a/source/xamarin-macios/src/UIKit/UIApplication.cs:63 
  at Useall.Useall.UseApp.iOS.Application.Main (System.String[] args) [0x00001] in C:\Desenvolvimento\Useall.Useall\Useall.Useall.UseApp\Useall.Useall.UseApp\iOS\Main.cs:12 
The app has been terminated.

I can't always simulate.

BjornB

@MichaelRumpler in styles-v21, remote the statusbarcolor=transparent

PaulDiPietro

@LGMaestrelli Is that a regression new to 2.4, or something separate? If you can somewhat reliably reproduce it, do file a bug with one we can run to take a look at, assuming this wasn't already reported somewhere and has slipped my mind.

LGMaestrelli

@PaulDiPietro

It started to happening on 2.4. I didn't open a bug report because I can't simulate or figure out some reason.
Some times when I open a ContentPage with a simple ListView the app crashes on iOS.

This is another crash that is happening and I can't simulate:

Count must be positive and count must refer to a location within the string/array/collection.
Parameter name: count (System.ArgumentOutOfRangeException)
  at System.Array.IndexOf[T] (T[] array, T value, System.Int32 startIndex, System.Int32 count) [0x00034] in /Library/Frameworks/Xamarin.iOS.framework/Versions/10.12.0.18/src/mono/mcs/class/corlib/corert/Array.Portable.cs:730 
  at System.Collections.Generic.List`1[T].IndexOf (T item) [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/10.12.0.18/src/mono/mcs/class/referencesource/mscorlib/system/collections/generic/list.cs:622 
  at System.Collections.Generic.List`1[T].Remove (T item) [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/10.12.0.18/src/mono/mcs/class/referencesource/mscorlib/system/collections/generic/list.cs:831 
  at Xamarin.Forms.Element.Xamarin.Forms.IElement.RemoveResourcesChangedListener (System.Action`2[T1,T2] onchanged) [0x00
009] in C:\BuildAgent3\work\ca3766cfc22354a1\Xamarin.Forms.Core\Element.cs:223 
  at Xamarin.Forms.Element.set_Parent (Xamarin.Forms.Element value) [0x0001d] in C:\BuildAgent3\work\ca3766cfc22354a1\Xamarin.Forms.Core\Element.cs:188 
  at Xamarin.Forms.ListView.UnhookContent (Xamarin.Forms.Cell content) [0x00007] in C:\BuildAgent3\work\ca3766cfc22354a1\Xamarin.Forms.Core\ListView.cs:365 
  at Xamarin.Forms.ItemsView`1[TVisual].Xamarin.Forms.IItemsView<TVisual>.UnhookContent (TVisual content) [0x00000] in C:\BuildAgent3\work\ca3766cfc22354a1\Xamarin.Forms.Core\ItemsView.cs:68 
  at Xamarin.Forms.Internals.TemplatedItemsList`2+<UnhookItem>d__153[TView,TItem].MoveNext () [0x00016] in C:\BuildAgent3\work\ca3766cfc22354a1\Xamarin.Forms.Core\TemplatedItemsList.cs:1205 
--- End of stack trace from previous location where exception was thrown ---
  at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /Library/Frameworks/Xamarin.iOS.framework/Versions/10.12.0.18/src/mono/mcs/class/referenceso
urce/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:151 
  at System.Runtime.CompilerServices.AsyncMethodBuilderCore+<>c.<ThrowAsync>b__6_0 (System.Object state) [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/10.12.0.18/src/mono/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/AsyncMethodBuilder.cs:1018 
  at UIKit.UIKitSynchronizationContext+<Post>c__AnonStorey0.<>m__0 () [0x00000] in /Users/builder/data/lanes/4991/4a279c9a/source/xamarin-macios/src/UIKit/UIKitSynchronizationContext.cs:24 
  at Foundation.NSAsyncActionDispatcher.Apply () [0x00000] in /Users/builder/data/lanes/4991/4a279c9a/source/xamarin-macios/src/Foundation/NSAction.cs:163 
--- End of stack trace from previous location where exception was thrown ---
  at (wrapper managed-to-native) UIKit.UIApplication:UIApplicationMain (int,string[],intptr,intptr)
  at UIKit.UIApplication.Main (System.String[] args, System.IntPtr principal, System.IntPtr delegate) [0x00005] in /Users/builder/data/lan
es/4991/4a279c9a/source/xamarin-macios/src/UIKit/UIApplication.cs:79 
  at UIKit.UIApplication.Main (System.String[] args, System.String principalClassName, System.String delegateClassName) [0x00038] in /Users/builder/data/lanes/4991/4a279c9a/source/xamarin-macios/src/UIKit/UIApplication.cs:63 

PaulDiPietro

@LGMaestrelli We can keep this in mind and if you find a way to reproduce the errors, let us know (and like I said, even a semi-reliable one is definitely better than none at all). It's obviously tougher if we can't narrow down a scenario that causes it, but we want to prevent these regressions from getting into stable. Could you also describe what the app's doing when it occurs?

MichaelRumpler

@BjornB said:
@MichaelRumpler in styles-v21, remote the statusbarcolor=transparent

Thanks, that fixed it. That line probably crept in from my splash theme.
It's just strange, that this worked in XF < 2.4.

I closed the bug.

batmaci

@batmaci said:
When using masterdetail page, if I minimize or screen lock and come back to app, OnAppearing method of All pages on the stack are executed in Android. is this not a bug? Is this how it supposed to work in Android?

wow, i just saw this. https://github.com/xamarin/Xamarin.Forms/pull/450
If it works, it is awesome.

LGMaestrelli

@PaulDiPietro

I was able to simulate the problem and I've created a bug report 59042

I hope you guys can figure it out....

Thank you

batmaci

I reported this issue through syncfusion tool but it seems like no progress on it
https://bugzilla.xamarin.com/show_bug.cgi?id=58695

predalpha

Hello,

im facing unhandled exception issue under Android (works on UWP) while navigating inside a tapgesture.

Below Sample code :

public ICommand PopPageCommand { get; set; }

    public Page1()
    {
        InitializeComponent();
        PopPageCommand = new Command(PopPageBack);
        this.BindingContext = this;
    }

    private async void PopPageBack(object obj)
    {
        await Navigation.PopAsync(true);
    }

Navigation.PopAsync will raise that issue if the command is binded to a tapgesture command.

PaulDiPietro

@predalpha Can you please file a bug with a reproduction project and also let us know if this is a regression?

predalpha

@PaulDiPietro : sorry i wont make a repo for that.
You can test the page code below. If you dont encounter the error i will make a repo.
Seems to be a regression from the previous stable release.

For information Page1 is pushedAsync by the mainpage

App.cs
public App()
{
InitializeComponent();
MainPage = new NavigationPage(new App1.MainPage());
}

Xaml Page1

<?xml version="1.0" encoding="utf-8" ?>

<ContentPage.Content>

        <BoxView HeightRequest="100" WidthRequest="100" BackgroundColor="Red">
            <BoxView.GestureRecognizers>
                <TapGestureRecognizer Command="{Binding PopPageCommand}" NumberOfTapsRequired="1" />
            </BoxView.GestureRecognizers>
        </BoxView>
    </StackLayout>
</ContentPage.Content>

Code-Behind Page1

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Input;
using Xamarin.Forms;
using Xamarin.Forms.Xaml;

namespace App1
{
[XamlCompilation(XamlCompilationOptions.Compile)]
public partial class Page1 : ContentPage
{
public ICommand PopPageCommand { get; set; }

    public Page1()
    {
        InitializeComponent();
        PopPageCommand = new Command(PopPageBack);
        this.BindingContext = this;
    }

    private async void PopPageBack(object obj)
    {
        await Navigation.PopAsync(true);
    }
}

}

PhilippSumi

@predalpha said:

I didn't run into that issue specifically, but had some issues with gesture event handlers myself. What worked well there for me was a Device.BeginInvokeOnMainThread rather than executing from withing the gesture handler in order to enqueue the execution with the UI message pump. Maybe that'll help you short term.

predalpha

Hi @PhilippSumi ,

For sure i confirm this is a regression as it works well in 2.3.4.267.
I had already tried BeginInvoke without success. The only thing to do in order to avoid that error on the pre-release is to wait before PopAsync : await Task.Delay(400);

I revert to 2.3.4.267 in order to avoid polluting my code.

PaulDiPietro

I've filed a bug for that issue so it's on our radar to get looked at as a regression.

predalpha

Thank you

DavidOrtinau

We've published 2.4.0.269-pre2 for review. Please give it a look, and read the release notes for a list of known issues we're continuing to track and resolve.

NMackay

@DavidOrtinau said:
We've published 2.4.0.269-pre2 for review. Please give it a look, and read the release notes for a list of known issues we're continuing to track and resolve.

When will it become stable? This causes real issues as our control providers won't support it until it becomes stable but we're in limbo as we're developing against 2.3.5-pre6 to help suppress several issues.

If a stable release is months away it affects how we ship our app.

JKay

for the flags feature can someone create an Enum or at least a class containing Static Constant string's
I.e.

Forms.SetFlags(FormsFeatures.FastRenderers)

Magic strings are a pet hate

ClintStLaurent

@NMackay said:

@DavidOrtinau said:
We've published 2.4.0.269-pre2 for review. Please give it a look, and read the release notes for a list of known issues we're continuing to track and resolve.

When will it become stable? This causes real issues as our control providers won't support it until it becomes stable but we're in limbo as we're developing against 2.3.5-pre6 to help suppress several issues.

If a stable release is months away it affects how we ship our app.

Same/similar situation here. In an enterprise-grade business we can't just pull PR's and -pre all willy nilly. Company policy is official stable release updates. If I was a freelancer whacking in my home-office it would be different.

LGMaestrelli

@PaulDiPietro

Is some one looking into this bug?
I can not tell the users to keep trying to open a page until it works.

PaulDiPietro

@LGMaestrelli We have an active list of regressions for 2.4.0 to be investigated, which that bug is a part of.

ClayZuvich

@DavidOrtinau Any possibility of this bug getting fixed on Android in the 2.4 release? The workaround is to not use a Modal page in the mentioned scenario.

https://bugzilla.xamarin.com/show_bug.cgi?id=43692

MohamedCHOUCHANE

@JKay said:
for the flags feature can someone create an Enum or at least a class containing Static Constant string's
I.e.

Forms.SetFlags(FormsFeatures.FastRenderers)

Magic strings are a pet hate

+1000 Great idea.

You can submit your idea in the Xamarin Forms Evolution topic (https://forums.xamarin.com/categories/xamarin-forms-evolution)

PeteSchmitz

We're also hitting a tapgesture-related bug - stack and repro at https://bugzilla.xamarin.com/show_bug.cgi?id=59130

DevNative

This Label crash on iOS is still existing in 2.4.0.269-pre2

https://bugzilla.xamarin.com/show_bug.cgi?id=52834

Unfortunately I cannot provide a reproduction either, but Mustafa Jalil posted some findings.

PhilipGruebele

https://bugzilla.xamarin.com/show_bug.cgi?id=59130 is a show stopped for us as well.

LGMaestrelli

I'm facing the same problem as @PhilipGruebele as well.

NamyslawSzymaniuk

@DavidOrtinau any plan for 2.4.0-pre3 release in near future - a few days?
This issue is really critiall for most mobile apps - https://bugzilla.xamarin.com/show_bug.cgi?id=59097 and it's also causing crashing of my app.

JohnHardman

@PaulDiPietro - Regarding "Behavior change: Calling Focus on a Picker on WinRT/UWP will now open the drop down."

I need to be able to programmatically move the focus to Picker, DatePicker and TimePicker on UWP without the picker dropping down. I am not particularly concerned whether this is the default behavior, as long as it can be done easily or relatively easily (i.e. it would be best if controlled through a property on the appropriate picker, but I would not be overly fussed if a simple custom renderer were required - as long as whatever needs changing is not internal or private to the underlying renderer).

MarkRadcliffe

@NamyslawSzymaniuk said:
@DavidOrtinau any plan for 2.4.0-pre3 release in near future - a few days?
This issue is really critiall for most mobile apps - https://bugzilla.xamarin.com/show_bug.cgi?id=59097 and it's also causing crashing of my app.

I am getting this crash without popping. I get the same crash from touching the screen during adding of an element also. I don't even use the tap handlers! So a feature I don't use breaks my code

NamyslawSzymaniuk

@MarkRadcliffe said:

@NamyslawSzymaniuk said:
@DavidOrtinau any plan for 2.4.0-pre3 release in near future - a few days?
This issue is really critiall for most mobile apps - https://bugzilla.xamarin.com/show_bug.cgi?id=59097 and it's also causing crashing of my app.

I am getting this crash without popping. I get the same crash from touching the screen during adding of an element also. I don't even use the tap handlers! So a feature I don't use breaks my code

Well, it's propably crashing also for you (even not using gesture recognizers), as it's crashing on whole gesture listener (which would do nothing, when you are not handling tapping, or do logic for your handling)
https://github.com/xamarin/Xamarin.Forms/pull/1118/files#diff-eaa7436a37f23b14e1518b46a170c69a

That's why I'm asking @DavidOrtinau for pre3 release date, as it's really blocker.

EZHart

@JKay said:
for the flags feature can someone create an Enum or at least a class containing Static Constant string's
I.e.

Forms.SetFlags(FormsFeatures.FastRenderers)

Magic strings are a pet hate

Experimental features may change - the flag may change or the feature may simply not be included as part of Forms in the future (possibly removed entirely, or moved to a separate package). If we introduce a compile-time dependency like an enumeration or named string, we can't remove it or modify it without the risk of breaking someone's build.

NamyslawSzymaniuk

Any plan for this - https://bugzilla.xamarin.com/show_bug.cgi?id=51854 @DavidOrtinau ? It's just Confirmed from 8 months ...

PhilippSumi

@EZHart said:

@JKay said:
for the flags feature can someone create an Enum or at least a class containing Static Constant string's
I.e.

Forms.SetFlags(FormsFeatures.FastRenderers)

Magic strings are a pet hate

Experimental features may change - the flag may change or the feature may simply not be included as part of Forms in the future (possibly removed entirely, or moved to a separate package). If we introduce a compile-time dependency like an enumeration or named string, we can't remove it or modify it without the risk of breaking someone's build.

To be honest, I'd prefer my build breaking much, much rather than my app pretending that everything if fine while the behavior at runtime becomes erroneous, which is something I might realize only in production or after chasing some red herrings...