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Xamarin.Forms 1.3.0 Released

TheRealJasonSmithTheRealJasonSmith USXamarin Team Xamurai
edited December 2014 in Xamarin.Forms

Important notes:

  • Generators for XAML pages should to be updated to use the new tool MSBuild:UpdateDesignTimeXaml instead of MSBuild:Compile
  • Grid default is now *
  • This release does not contain support for iOS 64bit. If you need iOS 64bit support please use Xamarin.Forms 1.3.1-pre1. It is otherwise identical to 1.3.0, however it requires Xamarin.iOS 8.6, which is available in the beta channel.

New API and Enhancements

  • Add MasterDetailPage.ShouldShowToolbarButton method to enable control over the appearance of the toolbar button.
  • Device.GetNamedSize (NamedSize size, Type targetType); Same as Device.GetnamedSize (NamedSize size, Element element) but doesn't require an instance.
  • MasterDetailPage.MasterBehavior : Used to control how the MasterDetailPage renderers the split view between the Master and Detail. Allowed values are:
public enum MasterBehavior
  • VisualElement.Navigation now contains overloads for all Pushing and Popping methods that accept a boolean parameter to enable/disable animations.
  • INavigation contains methods needed for more complex navigation scenarios:

    public interface INavigation
        IReadOnlyList<Page> NavigationStack { get; }
        IReadOnlyList<Page> ModalStack { get; }
        void RemovePage (Page page);
        void InsertPageBefore (Page page, Page before);
        Task PushAsync (Page page);
        Task<Page> PopAsync ();
        Task PopToRootAsync ();
        Task PushModalAsync (Page page);
        Task<Page> PopModalAsync ();
        Task PushAsync (Page page, bool animated);
        Task<Page> PopAsync (bool animated);
        Task PopToRootAsync (bool animated);
        Task PushModalAsync (Page page, bool animated);
        Task<Page> PopModalAsync (bool animated);
  • New Application class to replace previous methods of turning a Page into a platform specific object.

  • New member on Page: protected virtual bool OnBackButtonPressed (): Override in order to handle physical back button press events. Events bubble down from root page and back up. Unhandled back button events will cause the app to exit. NavigationPage and the Platform still handle the back button as expected, however it is now possible to intercept and modify these behaviors. Not overriding this method retains the existing back button behavior.
  • DependencyService now has Register methods for users needing more advanced ways to register dependencies.
  • WidthRequest, HeightRequest, MinimumWidthRequest, and MinimumHeightRequest are now BindableProperties
  • IViewController, IVisualElementController, and IElementController now available and explicitly implemented on VisualElement. These interfaces will eventually replace all internal API's currently used to communicate between platform renderers and the frontend API.
  • IElementController.SetValueFromRenderer allows for updating of BindableProperties from renderers without accidentally clearing bindings.
  • XAML now supports text as the content node in Label: <Label>Hello World</Label>
  • Pin now has a Clicked property for detecting when the user taps or clicks on a Map pin after the information window is visible.
  • Layout constructor is now marked protected and not internal
  • Styles support Behaviors and Triggers
  • DataTrigger and MultiTrigger added
  • VisualElement.IsFocused is now a BindableProperty
  • Use * as default grid size
  • StaticResource searches in Application.Current.Resources too
  • Add NavigationPage.HasBackButton
  • Fix Fuchsia spelling, Obsolete the old spelling
  • TypeConverter on FontSize
  • SearchBar.CancelButtonColor (currently only supported on iOS)
  • ListView context actions

Bug Fixes


  • Bindings are culture unaware
  • SetValue now properly overrides settings from a Style when the Style is applied later.
  • Grid now has more nuanced reflow logic for things like labels. This fixes some cases where grid would end up either too small or too large for its content.
  • Fix crash in XAML with DataTemplates and event subscription.
  • ListView/TableView respect WidthRequest/HeightRequest again (regression in 1.3.0-pre2)
  • No longer crash when trying to download/access the same UriImageSource on hundreds of images (System.IOException).
  • Fix issue where Grid sometimes measured out taller than it should, especially in ListView/StackLayout. Grid now prefers to expand in the direction of a "defined" constraint, which tends to match expected behavior when measuring. If both constraints are Infinite, previous behavior is retained.
  • BindableObject.SetValue will now properly perform loss-less conversions on base types. e.g. Calling slider.SetValue (Slider.ValueProperty, 6.0f) will now work correctly.
  • Fix issue where StackLayout in a Horizontal orientation would return an incorrect MinimumHeight in GetSizeRequest.
  • Adding a bad Path to a UriImageSource no longer crashes
  • Improved XAML error reporting
  • Fix crash where calling Navigation.PushAsync from re-initialized View sometimes crashed
  • Fix error where cloning a Binding did not clone the Source parameter
  • IsPresented is now respected correctly when using MasterDetailPage. May throw exception now if IsPresented is set to a disallowed value with MasterBehavior.
  • Several bugs relating to culture invariance in XAML parsing.
  • ThicknessConverter no longer depends on device culture
  • Label properly resizes after setting Label.FontSize/Font/FontAttributes Bug
  • XAML InitializeComponent calls in some apps this will result in a massive performance improvement when loading pages.
  • Serialization now property supports DataMemberAttributes
  • ListView and TableView now return consistent sizing across all platforms. This change should not affect most apps, however some apps suffering from inconsistent sizing with ListViews/TableViews should find the situation better.
  • Small set of changes to Layout to enable performance optimization with unneeded measure invalidation.
  • Don't throw NRE in ResourceDictionaries when reparenting
  • Fix map issue with IsShowingUser and location
  • fix binding against arrays (
  • Resolve issue where Labels didn't reflow correctly inside of grids
  • RelativeLayout now gives sane error when relative to non-child view
  • fix NRE on removing ListView items (
  • x:Reference now works inside other markup extensions.


  • Pressing back and re-entering the app now cleans up the old Activity and associated renderers. This fixes both memory leak issues and some crashes.
  • Label.FontSize = 18 no longer accidentally gives a font size of 14 on any devices.
  • Fix another case where ScrollView content could flow outside of bounds (yay).
  • Fix crash in WebView when being removed from the visual tree.
  • Map no longer re-centers on Layout.
  • MasterDetailPage container width now matches android design guidelines on tablets. (No longer insanely wide).
  • SwitchCell height is no longer squished
  • No longer crashes on Android 5.0
  • No longer renders with a black bar at the bottom of Android 5.0 devices
  • Other compatibility fixes with Android 5.0
  • WebViewRenderer now uses correct path for finding resources
  • Fix issue where calling SetPage multiple times would throw an exception
  • Fix crash when restarting the Activity introduced in last pre-release
  • Fix issue where ListView.SelectedItem = null sometimes did not work as expected.
  • Fix issues where Switch did not show on some Samsung devices
  • Fix issue where rotation ignored the anchor point
  • Fix Button text allignment issue (,


  • Renderers are now properly re-used in ListView. Performance enhancement.
  • iOS 8 now uses UIAlertController for alerts.
  • Fix a case where the keyboard could end up overlapping the input area.
  • Mixing swipe to go back and press to go back no longer results in a blank page.
  • ContextAction More/Cancel buttons now translate properly
  • ImageCell no longer flashes old image on cell re-use.
  • Slider now updates bindings correctly due to conversion fix.
  • Button.Image is now rendered with original image to match other platforms
  • Editor now scrolls to the correct location when a keyboard is shown
  • Fix NullReferenceException when assigning to SearchBar.BackgroundColor
  • Fix issue where PushModalAsync could sometimes result in a unhandled exception from UIKit.
  • MasterDetailPage now disposes of child renderers correctly, resolves a memory leak.
  • Fix issue where cells could not be unselected using blank rows.
  • WebViewRenderer now uses correct path for finding resources
  • Resolve issue where calling CreateViewController multiple times would cause an exception
  • Use proxy when downloading images if configured on device.
  • Partial swipes on a NavigationPage no longer cause the NavigationPage to get out of sync with the UINavigationController
  • ActionSheet now correctly shows on iOS 8
  • ActionSheet no longer gets incorrectly positions when rotating while visible.
  • Fix issue on Translating views of zero size
  • Select picker first item (
  • TabbedPage now updates icons correctly
  • Fix several memory leaks
  • Modal dialog scrolls to far (
  • Fix NRE when disposing some renderers.


  • Fix crash when pressing back button with active ActionSheet.
  • TableView no longer selects wrong item when in Landscape mode.
  • OpenUriAction now uses LaunchUriAsync.
  • Back button now closes ActionSheets and Alerts before attempting Navigation.
  • Picker no longer shows a bunch of blank entries.
  • ListView selection now properly shows up.
  • ListView allows selection of items multiple times in a row if the user calls SelectedItem = null. This behavior matches other platforms correctly now.
  • Label now reports the correct minimum width to match other platforms.
  • Fix crash in Picker


  • Fantastic work! Been looking forward to this release :D

    Amazing timing too :)

  • JunZhang.3823JunZhang.3823 USMember ✭✭
    edited December 2014

    After having updated to version I got compiling error:

    Error MT3001: Could not AOT the assembly '/Users/PROJECT_PATH/iOS/obj/iPhone/Debug/mtouch-cache/Build/PROJECT_NAME.dll' (MT3001)

    btw I have switched to iOS beta channel and haven't migrated src code to support iOS 64 bit.
    Xcode 6.1.1 (6611) Build 6A2008a

    One weird thing is this error only happens when I load code to real devices(iphone 5 iOS8.1.2 & ipad mini 2 iOS8.1.2), for all simulators it compiles seamlessly.

    Any idea would be appreciated.

  • MikeScott8MikeScott8 USUniversity
    edited December 2014

    OK since Im off today I had some free time and came back to playing with Xamarin Forms. After creating new solution I upgraded to this version. It's been a while since I used Xamarin forms, so dont know if this was introduced in this version or previous and I am doing something wrong.

    I am trying to set a label's FontSize using the below (in the label constructor call):

    FontSize = Font.SystemFontOfSize(NamedSize.Medium, FontAttributes.Bold).FontSize;

    and the label disappears. I added a line to do the Font.SystemFontOfSize call separately and the font that is returned from that call has a FontSize of zero. I tried setting the Font of the label to the result of the call but see that Font is marked Obsolete so thats probably not the right way to go.

    What am I doing wrong? what is the CURRENT (as it seems to change over time) best practice for setting label font/font size?


  • Thanks for this!! After updating to, when using Style in my main page, I get a XamlParseException error when running the project - "No embeddedresources found for ProjectName.Pages.MainPage"..... In order for it to run, need to clean the solution, then run it, and the styles then work as expected.

    Also - would appreciate some xaml guidance on DataTriggers. For example, in a ListView, let's say I have a property named "IsComplete" on objects in my collection, and want a label's text color to display as green.

    Thanks in advance!

  • FredrikHaglundFredrikHaglund SEUniversity, Developer Group Leader ✭✭

    Tip! This page from Xamarin documentation might be helpful:
    Updating Existing Xamarin.Forms Apps

    It describes more in detail how to change your startup code when your project is created with templates intended for earlier Xamarin Forms versions.

  • Hi Jason,

    I am getting this error on Tabbed Page after updating my current project from 1.2.3 to 1.3.0 -

    [MonoDroid] System.InvalidOperationException: You MUST call Xamarin.Forms.Init(); prior to using it.
    [MonoDroid] at Xamarin.Forms.Device.get_Info () [0x00000] in :0 "

    Let me know if you require more info.


  • DarrelDarrel USMember
    edited December 2014

    @MikeScott8‌ if you are still having the issue with FontSize, as I also did, this thread should have a solution:

    aLabel.FontSize = Device.GetNamedSize(NamedSize.Large, aLabel);

    I think using a style (such as TitleStyle) is encouraged instead of using a size directly.

  • Thanks Fredrik! Checked that article out, was helpful. In my android project, in MainActivity, now inheriting from FormsApplicationActivity, and using LoadApplication (new App ()); instead of GetMainPage

    Updated the PCL project, so that App inherits from Application.

    I still get "No embeddedresources found for ProjectName.Pages.MainPage" if I update any XAML property, then run. Still have to clean the project first

  • TheRealJasonSmithTheRealJasonSmith USXamarin Team Xamurai

    @DeepeshKhanna.4853‌ are you calling Xamarin.Forms.Init before you call any other Xamarin.Forms API? That error is indicative of calling a Forms API before calling Init.

  • TheRealJasonSmithTheRealJasonSmith USXamarin Team Xamurai

    @JunZhang.3823‌ if you want to use the beta channel, you must use the 1.3.1 pre-release.

  • laygrlaygr MXMember, University
    edited December 2014

    Just in time for Christmas!

  • FredrikHaglundFredrikHaglund SEUniversity, Developer Group Leader ✭✭

    @TimothyStrumfels‌ If you select a Xaml file and check its properties, do you have Compile or UpdateDesignTimeXaml as Build Tool?

  • LucaBLucaB ITMember

    And ListView is still broken and unusable (on iOS at least).

    It's the already reported error "MonoTouch: Received unhandled ObjectiveC exception: NSInternalInconsistencyException Invalid update: invalid number of rows in section 0. The number of rows contained in an existing section after the update (1) must be equal to the number of rows contained in that section before the update (5), plus or minus the number of rows inserted or deleted from that section (1 inserted, 0 deleted) and plus or minus the number of rows moved into or out of that section (0 moved in, 0 moved out)."

    Which happens because whoever wrote the code had no clue about the implications of doing the updates asynchronously on the UI thread.

    (if you missed the earlier reports, to reproduce just bind a ListView to an ObservableCollection and call Add on it several times in a row some time after the ListView has been shown)

  • P3PPPP3PPP JPMember ✭✭

    Styles support Behaviors and Triggers

    How do i make custom Behavior and custom Trigger? Behavior and TriggerBase only has internal constructor, my class can't inherit them.

  • Fredrik, it was compile..... that should do it, thanks for the help

  • TheRealJasonSmithTheRealJasonSmith USXamarin Team Xamurai

    @LucaB I can't reproduce the issue by doing what you have suggested. There are no errors when I simply call Add multiple times on the observable collection, the new data shows up fine. Are you perhaps calling Add from a thread?

  • TheRealJasonSmithTheRealJasonSmith USXamarin Team Xamurai

    @P3PPP‌ custom Triggers are not currently supported

  • LucaBLucaB ITMember
    edited December 2014

    @JasonASmith‌ It looks like it needs a Clear call before the Adds to trigger the bug, sorry.

    This code seems to trigger it reliably (generate a new XF project with stable XS, then upgrade the XF package to 1.3.0 and paste this in):

    using System;
    using Xamarin.Forms;
    using System.Collections.ObjectModel;
    using System.Threading.Tasks;
    namespace XFListView
        public class App
            static ObservableCollection<string> _collection = new ObservableCollection<string> ();
            public static Page GetMainPage ()
                var listView = new ListView ();
                var model = new {Collection = _collection};
                listView.SetBinding(ListView.ItemsSourceProperty, new Binding("Collection"));
                var page = new ContentPage { 
                    Content = listView
                page.BindingContext = model;
                Device.BeginInvokeOnMainThread(() => {
                    _collection.Clear ();
                return page;

    Result (with iPhone 6 Plus iOS 8.1 emulator).

    Printed to console:
    2014-12-25 05:24:47.566 XFListViewiOS[36608:766547] *** Assertion failure in -[UITableView _endCellAnimationsWithContext:], /SourceCache/UIKit_Sim/UIKit-3318.16.14/UITableView.m:1582

    And this exception:
    NSException {Invalid update: invalid number of rows in section 0. The number of rows contained in an existing section after the update (1) must be equal to the number of rows contained in that section before the update (1), plus or minus the number of rows inserted or deleted from that section (1 inserted, 0 deleted) and plus or minus the number of rows moved into or out of that section (0 moved in, 0 moved out).} MonoTouch.Foundation.NSException

  • LucaBLucaB ITMember

    I think you introduced this around 1.3.0-pre1 when you started calling Device.BeginInvokeOnMainThread unconditionally in ListViewRenderer rather than only when off the main thread.

    If you run that code on another thread, I think 1.2.3 is affected too (haven't tested, just looked at the code).

    The problem seems to be that you are scheduling updates in ListViewRenderer via Device.BeginInvokeOnMainThread and then you are accessing the state of collection in the callback, which is of course completely random.

    I think you need to keep a "shadow copy" of the ObservableCollection, bind the iOS UI to that; only OnCollectionChanged should access the user-visible collection and it should put all the data needed to update the "shadow copy" in a FIFO queue (including the objects themselves), and schedule via BeginInvokeOnMainThread a callback that pops an entry from the queue, updates the shadow copy from the data popped off the queue and updates the iOS control.

  • LucaBLucaB ITMember
    edited December 2014

    Actually in WPF it seems you can't update ObservableCollections from non-UI threads (, so a quicker fix would be to adopt that limitation and thus replacing Device.BeginInvokeOnMainThread with an assertion of running on the main thread and a synchronous call in ListViewRenderer.OnCollectionChanged.

  • Does this release support the unified API? I'm not seeing any assemblies under the Xamarin.IOS10 platform in the nuget download. -pre4 had these assemblies.

  • @JasonSmith .. I do call the Forms.Init() initially. I have a content page as my initial page from where I navigate to a tabbed page. The content page loads correctly but I get the "Unhandled exception" at the tabbed page.

    This was working fine before on v1.2.3 of forms.


  • adamkempadamkemp USInsider, Developer Group Leader mod

    @ChrisTartamella.1859‌ , no. That's right there at the top of this post. You have to use 1.3.1, which is now in prerelease.

  • @adamkemp‌ I have no idea how I missed that. Thanks!

  • ApurvaGoyalApurvaGoyal USMember ✭✭
    edited December 2014

    I am getting exception after upgrading to 1.3.0 and inheriting from Application class as explained in document-

    I am using following code to create new page in App class-

      ViewFactory.Register<MainMenuView,MainMenuViewModel> ();
      var home = ViewFactory.CreatePage<MainMenuViewModel>();
      MainPage= new NavigationPage (home);

    However now I get following exception-

    System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.Exception: Method not found: 'Xamarin.Forms.Binding..ctor'.
    at wpMobile.Views.BaseView..ctor () [0x00000] in c:\Projects\wp-express\wp-mobile-xamarin\src\wpMobile\wpMobile\Views\BaseView.cs:13
    at wpMobile.Views.MainMenuView..ctor () [0x00007] in c:\Projects\wp-express\wp-mobile-xamarin\src\wpMobile\wpMobile\Views\MainMenuView.cs:43
    at at (wrapper managed-to-native) System.Reflection.MonoCMethod:InternalInvoke (System.Reflection.MonoCMethod,object,object[],System.Exception&)
    at System.Reflection.MonoCMethod.InternalInvoke (System.Object obj, System.Object[] parameters) [0x00000] in :0
    --- End of inner exception stack trace ---
    at at System.Reflection.MonoCMethod.InternalInvoke (object,object[])
    at at System.Activator.CreateInstance (System.Type,bool)
    at at System.Activator.CreateInstance (System.Type)
    at at Xamarin.Forms.Labs.Mvvm.ViewFactory.CreatePage<wpMobile.ViewModels.MainMenuViewModel> (System.Action`2<wpMobile.ViewModels.MainMenuViewModel, Xamarin.Forms.Page>) <0x00417>
    at wpMobile.App..ctor () [0x00093] in c:\Projects\wp-express\wp-mobile-xamarin\src\wpMobile\wpMobile\App.cs:39
    at wpMobile.Android.MainActivity.OnCreate (Android.OS.Bundle) [0x00011] in c:\Projects\wp-express\wp-mobile-xamarin\src\wpMobile\Android\MainActivity.cs:26
    at Android.App.Activity.n_OnCreate_Landroid_os_Bundle_ (intptr,intptr,intptr) [0x00011] in /Users/builder/data/lanes/monodroid-mlion-monodroid-4.20-series/ba9bbbdd/source/monodroid/src/Mono.Android/platforms/android-19/src/generated/Android.App.Activity.cs:2179
    at at (wrapper dynamic-method) object.7326e589-a609-44c9-892a-c458585f9e8c (intptr,intptr,intptr)

  • ApurvaGoyalApurvaGoyal USMember ✭✭
    edited December 2014

    This has completely broken my app !! Am I missing something here? Here is my baseview class, I need urgent help please!

    public abstract class BaseView:Xamarin.Forms.Labs.Mvvm.BaseView

        public BaseView ()


    And here is the code in MainActivity-

      [Activity (Label = "wp Express", WindowSoftInputMode = SoftInput.AdjustPan,ConfigurationChanges =    ConfigChanges.ScreenSize | ConfigChanges.Orientation)]
    public class MainActivity : FormsApplicationActivity
        protected override void OnCreate (Bundle bundle)
            base.OnCreate (bundle);
            Xamarin.Forms.Forms.Init (this, bundle);
            LoadApplication(new App());
            //SetPage (App.GetMainPage ());
  • ApurvaGoyalApurvaGoyal USMember ✭✭

    I found the fix! I had to upgrade the xamarin.forms.labs to 1.2.1 pre-release!!!

  • DeanChalk.1376DeanChalk.1376 GBMember, University

    Sorry for being uninformed, but when you say released a version, or a version is in pre-release, what update channel are you referring to? I am on the stable channel, will I need to switch to beta or alpha in order to get this?

  • MihaMarkicMihaMarkic SI ✭✭✭✭

    @lucab @JasonASmith‌ I really hope you are not doing any synchronization in Forms. it is unnecessary preformance hit and probably a costly one.

  • FredrikHaglundFredrikHaglund SEUniversity, Developer Group Leader ✭✭

    @DeanChalk.1376‌ Xamarin.Forms is released as NuGet packages so you can choose which version you want regardless of Xamarin channel. Packages may have requirements on the platform they are used on but that's something you must read in the release notes. In this case 1.3.0 works on Xamarin Stable channel and 1.3.1-pre1 works with Xamarin Beta channel to test Unified 64-bit iOS API.

    If you open the NuGet package manager dialog you will find a checkbox (Xamarin Studio) or Drop-down (VS) to show pre-release packages.

  • IbrahimSusicIbrahimSusic BAMember
    edited December 2014

    My Code no't work in new update

                    <Button Text="{Binding Name}"  HorizontalOptions = "FillAndExpand">
                              <b:EventToCommand CommandNameContext="{b:RelativeContext rootControl}"
                                                             CommandParameter="{Binding .}" />
                      <Button Text="{Binding Quantity, Mode=TwoWay}"  />

    Help ...

  • MihaMarkicMihaMarkic SI ✭✭✭✭

    ListView memory overutilization (hence lags when scrolling) is still present.

  • @MihaMarkic‌ No work :(

  • MihaMarkicMihaMarkic SI ✭✭✭✭

    @IbrahimSusic‌ What doesn't work in your code exactly? BTW TwoWay binding for buttons isn't necessary (it is a oneway really).

  • @MihaMarkic‌ Return blank page, but all is ok in my model

  • TheRealJasonSmithTheRealJasonSmith USXamarin Team Xamurai

    @LucaB the point of the BeginInvokeOnMainThread call was never about thread safety, we still have teh same UI thread limitation WPF does. It was about delaying the invocation of certain things. That call does reliably come back in the order it is called (at least in a single threaded situation), and the delay serves a purpose (even if I will have to dig through the comments to remember what). I believe its dealing with an inconsistency issue elsewhere, either way I will fix it.

  • TheRealJasonSmithTheRealJasonSmith USXamarin Team Xamurai

    @MihaMarkic no you have to manually request synchronization.

  • MihaMarkicMihaMarkic SI ✭✭✭✭
    edited December 2014

    @JasonASmith‌ Excellent. That's ok then. While looking at ListView Images performance problem I've come across this method that it isn't really well optimized: Android's ListViewRendererListViewAdapter.GetCellForPosition(Int32). It creates a list and then calls an extension method that does unnecessary casts. Not the best way to have a best performance.

  • TheRealJasonSmithTheRealJasonSmith USXamarin Team Xamurai

    Yeah that file has not been past a performance optimization check. Most things have not yet. I am hoping we will get to dig into that Q1 this year.

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