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Xamarin.Forms 2.1.0-pre5 Released



  • BradChase.2654BradChase.2654 USMember ✭✭✭

    @TheRealJasonSmith Has Implicit styling on custom controls been fixed yet? So In App.xaml or root layout control of the app, can we do an implicit style on our own controls in a separate library? Currently we cannot do that but with the new control templates I think it would be very important.

  • TheRealJasonSmithTheRealJasonSmith USXamarin Team Xamurai

    @BradChase.2654 you mean application to subclasses? Implicit styles are explicitly defined as not apply to a subclass, though there are thoughts going around about how me might improve your selector support for what an implicit style applies to. Its not so much broken as its specced to work in a way you dont want like. There are solid reasons for the default being to not go to subclasses which I wrote down in OneNote somewhere but I'll be fucked if I can find it now (I cant, its lost to the OneNote gods).

  • BradChase.2654BradChase.2654 USMember ✭✭✭
    edited January 2016

    @TheRealJasonSmith hah yea thats exactly what I meant. When we use the TemplatedView will we be able to? So say we inherit from ContentView, implicit styling wont work, right I get that limitation right now, BUT. If we inherit from the TemplatedView, can we now? Or might we be able to in the future?

    EDIT: The functionality that I really need only applies to TemplatedView's not any "inherited" class really. If that makes sense.

  • TheRealJasonSmithTheRealJasonSmith USXamarin Team Xamurai

    we are evaluating options for the future

  • DominikWeberDominikWeber USMember

    On Windows UWP all my ListViews are empty :/

    This is my XAML:
    <ListView ItemsSource="{Binding Items}" ItemTapped="ListView_ItemTapped"> <ListView.ItemTemplate> <DataTemplate> <ViewCell> <Label Text="Test" /> </ViewCell> </DataTemplate> </ListView.ItemTemplate> </ListView>

  • Wasi.HaiderWasi.Haider USXamarin Team Xamurai

    This is awesome!

    Only issue I have run into so far is Element.Effects.Clear() will not work. You have to explicitly remove that Effect using Element.Effects.Remove or RemoveAt. Also, looks like you can only have one effect instance attached to one view.

  • TheRealJasonSmithTheRealJasonSmith USXamarin Team Xamurai

    @DominikWeber we're seeing this too in some other test apps, trying to work out the conditions that trigger it

  • ChaseFlorellChaseFlorell CAInsider, University mod

    Quick question, if BindableProperty.Create<TDeclarer, TPropertyType> is deprecated, what is it being replaced with?

  • TheRealJasonSmithTheRealJasonSmith USXamarin Team Xamurai

    @ChaseFlorell just use the non-generic version.

    Just a quick update on the non-showing up WP lists. Those will be fixed soon, we have discovered the root of the issue (an event wasn't properly tracked).

  • ChaseFlorellChaseFlorell CAInsider, University mod

    @TheRealJasonSmith is that simply for performance reasons?

  • AlanSpiresAlanSpires USBeta ✭✭

    anybody else getting consistent crashes when ListView.IsGroupingEnabled="true" bound to an observable collection?

    Have a bug filed here

  • AdrianKnightAdrianKnight USMember ✭✭✭✭

    @TheRealJasonSmith @BryanHunter.xam

    There are multiple reported bugs with regards to Android navigation bar. It's really difficult to theme it without running into styling bugs.

    Can these be given attention in the next release?

  • AdrianKnightAdrianKnight USMember ✭✭✭✭

    I think AppCompat made a buggy navigation bar even worse. I see multiple bugs on it in addition to the styling issues. Would really like to see some exclusive Android love. :) considering WP got lots of attention in this release.

  • NMackayNMackay GBInsider, University admin

    Found this one in AppCompat a while back. Can't really look it until it becomes more stable.

  • MarcoTMarcoT USMember ✭✭

    The Navigation with AppCompat is completely broken...Xamarin where are you? This bug is not a minor thing, we can't release app for Android if you don't fix it. Don't you think we deserve a reply?

  • Paul_RoyPaul_Roy FRMember ✭✭
    edited January 2016

    I am still getting a nullref exception when opening some views on WP (sometimes the first time I open it, usually the second time I open it).

    It never happened before 2.0 and never happens on any other platform.

    No stacktrace from the Unhandled exception. I do not even know where to begin.

    If I debug step by step it does not crash. Something must be called before it is assigned somewhere, but I have absolutely no clue on how to deal with this…

    Guess I am back on 1.5… again.

  • DanBDanB DEMember

    I discoverd that when using a stacklayout inside a grid on Windows Phone the ColumnDefinition
    is ignored. I found the reason / workaround for it:

    using Orientation = StackOrientation.Horizontal triggers the behavior -> result is XF is ignoring the sizes of the grid

      Label _Label1 = CreateListViewDeviceNameLabel();
      Label _Label2 = CreateListViewDeviceNameLabel();
     StackLayout _placeHolderStackLayout = new StackLayout
       // using StackLayout.Orientation propertie on XF 2.1.0 pre2 result in ignoring size definitions of the grid 
        Orientation = StackOrientation.Horizontal,
        Children =
      _gridMainLayout.Children.Add(_Label1, 1, 0);
      _gridMainLayout.Children.Add(_placeHolderStackLayout, 1, 1);
    private void CreateGrid()
      _gridMainLayout = new Grid();
      _gridMainLayout.RowDefinitions.Add(new RowDefinition { Height= new GridLength(45,GridUnitType.Absolute) }); // 
      _gridMainLayout.RowDefinitions.Add(new RowDefinition { Height= new GridLength(45,GridUnitType.Absolute) }); // 
      _gridMainLayout.ColumnDefinitions.Add(new ColumnDefinition { Width = new GridLength(90, GridUnitType.Absolute) }); //
      _gridMainLayout.ColumnDefinitions.Add(new ColumnDefinition { Width = new GridLength(100, GridUnitType.Absolute) });
      _gridMainLayout.ColumnDefinitions.Add(new ColumnDefinition { Width = new GridLength(80, GridUnitType.Absolute) }); //         
    public Label CreateListViewDeviceNameLabel()
      Label deviceNameLabel = new Label
        Text = "This Text should be cut off at the end of the 2 Column",
        TextColor = Color.White,
        LineBreakMode = LineBreakMode.NoWrap,
      return deviceNameLabel;


  • PaulDiPietroPaulDiPietro USXamarin Team Xamurai

    @MarcoT We are aware of the issue and it is being worked on.

  • ChaseFlorellChaseFlorell CAInsider, University mod

    Did something happen to the myView.RotateTo(); api?
    When I run 2.0.1, it runs as expected, when I update to this pre release, it crashes stating that animations must be run on the UI thread.

    I've got the source at work, but just remembered about it now and thought I'd ask before spending time wiring up a repro.

  • TheRealJasonSmithTheRealJasonSmith USXamarin Team Xamurai

    @Paul_Roy turn on break on throw in your exception settings so you can capture the stack trace and we will track down the issue.

  • TheRealJasonSmithTheRealJasonSmith USXamarin Team Xamurai

    @ChaseFlorell nope, what platform? Trace would be nice too :)

  • TheRealJasonSmithTheRealJasonSmith USXamarin Team Xamurai

    @MarcoT it is fixed in the next pre-release

  • DominikWeberDominikWeber USMember

    @TheRealJasonSmith have you been able to fix the UWP empty lists bug? I'm really waiting for this so I can implement the new features (Effects, ControlTemplate)

  • TheRealJasonSmithTheRealJasonSmith USXamarin Team Xamurai

    We have identified the problem yes. In general right now so long as you set your ListView.ItemsSource before the renderer is created you wont have an issue, obviously this is a blocker for release.

  • DominikWeberDominikWeber USMember

    I need to change the items multiple times during the app lifecycle, so this is not a usable workaround for me. When can I expect a fix for this issue? (I can't imagine this bug being too hard to fix)

  • TheRealJasonSmithTheRealJasonSmith USXamarin Team Xamurai

    Its already fixed, we're putting together the next pre soon.

  • DominikWeberDominikWeber USMember

    great, thanks!

  • Paul_RoyPaul_Roy FRMember ✭✭
    edited January 2016

    @TheRealJasonSmith Unfortunately I get nothing more, except that it comes from Xamarin.Forms.Platform.WP8.dll

    Full informations:

    System.NullReferenceException occurred
    Message: Exception thrown: 'System.NullReferenceException' in Xamarin.Forms.Platform.WP8.DLL
    Message: Exception thrown: 'System.NullReferenceException' in
    Additional information: Object reference not set to an instance of an object.

    If only I had a line on my code to help you…

  • Paul_RoyPaul_Roy FRMember ✭✭

    @TheRealJasonSmith But I have a dump if this helps.

  • AdamPAdamP AUUniversity ✭✭✭✭✭

    @TheRealJasonSmith - I couldn't see it in the list of bug fixes here but a regression in 2.0.1 where an IsPassword=True on an Entry and the Keyboard="Numeric" only shows the default keyboard on WinRT. Will repro and file that tomorrow morning.

    Also I have another PITA bug that I am still tracking down, same code works in iOS but not WinRT. Where I switch MainPage to another NavigationPage, pop, then push another page and it just turns to a black screen. No issue in iOS though.

    The interesting thing I found is for some reason it was adding it on the ModalStack as well as the NavigationStack (completely bizarre because I don't use the Modal Stack at all anywhere in my project) and I only push to the navigation stack. This issue seems to be with this release and previous ones, so it doesn't look like a regression.

    But its only occurring my larger project and having trouble replicating it with a smaller project. But just thought I would mention it in case it springs something to mind.

  • Paul_RoyPaul_Roy FRMember ✭✭

    @TheRealJasonSmith Sorry, third post…

    I was able to get a stacktrace with the .NET reflector (

  • MichaelRumplerMichaelRumpler ATMember ✭✭✭✭✭

    The additional features sound great, thanks for that!

    But why did you deprecate BindableProperty.Create<TDeclarer, TPropertyType>? I found those quite convenient. Is there any downside I'm not aware of?

  • TheRealJasonSmithTheRealJasonSmith USXamarin Team Xamurai

    @MichaelRumpler they come with a large performance and app size penalty on iOS

  • AnthonyRamirezAnthonyRamirez USUniversity ✭✭✭

    Hi @TheRealJasonSmith @MichaelRumpler

    Regarding Generic versions of Create () BindableProperty are no longer supported and deprecated;

    Is this referring to this?

    If so, this is essential to my custom controls.


  • TheRealJasonSmithTheRealJasonSmith USXamarin Team Xamurai

    They are not going away anytime soon, we deprecated them because their use should be heavily discouraged. That said I would be curious to know in what fashion they are essential to you as they literally just call the other API anyway.

  • AnthonyRamirezAnthonyRamirez USUniversity ✭✭✭
    edited January 2016

    Thanks for the quick reply @TheRealJasonSmith

    The more I think about it, I'd be surprised to see it go away. Maybe we are talking about different things. :)

    I use Bindable Properties when creating reusable controls that need to have bindable hook points to the outside world, ie the consumer of the control. If there is a different preferred way to create a property on a class which is bindable, that would likely work as well.

    As an example, in my app I have created a reusable TypedPicker < T >

    public class TypedPicker<T> : cPicker
        #region Bindable Property SelectedItem
        public T SelectedItem
            get { return (T) GetValue(SelectedItemProperty); }
            set { SetValue(SelectedItemProperty, value); }
        public static readonly BindableProperty SelectedItemProperty =
            BindableProperty.Create<TypedPicker<T>, T>(
                p => p.SelectedItem, default(T), propertyChanged: SelectedItemChanged);
       // Omitted SelectedItemChanged method to update internal values
        #region Bindable Property TypedItems
        public IList<T> TypedItems
            get { return (IList<T>) GetValue(TypedItemsProperty); }
            set { SetValue(TypedItemsProperty, value); }
        public static readonly BindableProperty TypedItemsProperty =
            BindableProperty.Create<TypedPicker<T>, IList<T>>(
                p => p.TypedItems, default(IList<T>), propertyChanged: TypedItemsChanged);                
       // Omitted TypedItemsChanged method to update internal values
        public IValueConverter ValueConverter { get; set; }
        // Omitted code, responsible for updating values and keeping everything in sync.


    This control can then be consumed in the following manner

            TypedItems="{Binding AvailableDateRanges}"
            SelectedItem="{Binding SelectedDateRange, Mode=TwoWay}"
            ValueConverter="{StaticResource DateRangeEnumToStringConverter}"

    Please let me know if you'd like any more info.

    Thanks again!

  • TheRealJasonSmithTheRealJasonSmith USXamarin Team Xamurai

    BindableProperties are not going away, you should just be using the non-generic version of BindableProperty.Create

  • AnthonyRamirezAnthonyRamirez USUniversity ✭✭✭
    edited January 2016

    Ok now I understand.

    It looks like I just need to update the way I call Create(). I do lose the typed propertyChanged method, but if it's for the better then I'm ok with that.

    Does this mean that I stand to have a performance gain by refactoring them? :)


    PS: Very happy to hear BPs are not going away.

  • TheRealJasonSmithTheRealJasonSmith USXamarin Team Xamurai

    Yes there will be a slight performance boost from it. Mostly in startup time.

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