Hi,
My Xamarin.Forms app works in debug mode, but if I build in release mode and I try to create an APK from VS 2017, it doesn't work.
The build process succeeded but the APK is not yet created.
My Xamarin.Forms version is 3.4.0.1008975 and my VS is up to date.

Target Android version is 9.0.

Here above the application logs:

Xamarin.VisualStudio.Publishing.ArchiveManager|Error|0|System.NotSupportedException: This type of CollectionView does not support changes to its SourceCollection from a thread different from the Dispatcher thread.
at System.Windows.Data.CollectionView.OnCollectionChanged(Object sender, NotifyCollectionChangedEventArgs args)
at System.Collections.ObjectModel.ObservableCollection1.OnCollectionChanged(NotifyCollectionChangedEventArgs e) at Microsoft.VisualStudio.PlatformUI.HierarchyItem.HierarchyItemCollection.OnCollectionChanged(NotifyCollectionChangedEventArgs e) at System.Collections.ObjectModel.ObservableCollection1.InsertItem(Int32 index, T item)
at System.Collections.ObjectModel.Collection1.Add(T item) at Microsoft.VisualStudio.PlatformUI.HierarchyItem.AppendChildren(IVsHierarchy hierarchy, UInt32 itemID, List1 appendedChildren)
at Microsoft.VisualStudio.PlatformUI.HierarchyItem.FillChildren()
at Microsoft.VisualStudio.PlatformUI.HierarchyItem.get_InternalChildren()
at Microsoft.VisualStudio.PlatformUI.HierarchyItem.get_Children()
at Clide.SolutionExplorerNode.get_Nodes() in E:\A_work\184\s\src\Clide\Solution\SolutionExplorerNode.cs:line 166
at Clide.ITreeNodeExtensions.<>c.b__1_0(ISolutionExplorerNode x) in E:\A_work\184\s\src\Clide.Interfaces\Extensions\ITreeNodeExtensions.cs:line 33
at Traverser.d__21.MoveNext() in E:\A\_work\184\s\src\Clide.Interfaces\Extensions\Traverser.cs:line 70 at System.Linq.Enumerable.<OfTypeIterator>d__951.MoveNext()
at System.Collections.Generic.List1..ctor(IEnumerable1 collection)
at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
at Clide.AndroidClideExtensions.GetAndroidResources(IProjectNode projectNode) in E:\A_work\293\s\src\Core\VisualStudio.Android\ProjectSystem\Extensions.cs:line 128
at Xamarin.VisualStudio.Android.Publishing.AndroidArchiveToolsService.CreateParameters(IProjectNode project) in E:\A_work\293\s\src\Core\VisualStudio.Android\Services\Publishing\Archival\AndroidArchiveToolsService.cs:line 186
at Xamarin.VisualStudio.Android.Publishing.AndroidArchiveToolsService.ArchiveAsync(IProjectNode project, IProgressReport progress, CancellationToken cancellationToken) in E:\A_work\293\s\src\Core\VisualStudio.Android\Services\Publishing\Archival\AndroidArchiveToolsService.cs:line 113
at Xamarin.VisualStudio.Publishing.ArchivableProjectBase.d__8.MoveNext() in E:\A_work\293\s\src\Core\VisualStudio.Publishing\Archival\ArchivableProjectBase.cs:line 30
--- End of stack trace from previous location where exception was thrown ---

Hello, i was wondering if it was possible to attempt this kind of binding on a listview.

<ListView 
ItemsSource="{Binding ListObject}" Grid.Column="{Binding PositionCol}" Grid.Row="{Binding PositionRow}">

<ListView.ItemTemplate>

    <DataTemplate>

        <TextCell Text="{Binding Name}"/>

    </DataTemplate>

</ListView.ItemTemplate>

</ListView>

List ListObject

each object containing:

int PositionCol
int PositionRow
string Name

Hello guys, I'm facing a problem working with LINQ and SQLite. I'm basically working with mid to large data sets (around 2k rows for now) and need to do some queries for filtering these items.

The problem is that it takes a few seconds for querying and rendering the rows on my ListView, and it's becoming annoying for the user. And more, we have a client that maybe is going to use this app, and it has more than 150k clients, so it is going to become a 150k rows data set.

I'm getting worried about this, and I'd like to know what are the best practices for working with large data sets on XF.

For now, I'm using SQLite, but soon I'm going to migrate to Realm (I heard it is a lot faster). And for preventing from querying from SQLite everytime I need some data (that is frequently), I'm loading all data I need just after Appearing event. Here's some example of what I'm doing:

// ProdutosService is basically a service for querying data about about products, prices and other stuff that I need
_produtos = ProdutosService.GetProdutos();
_grupos = ProdutosService.GetGrupos();
_tabelas = ProdutosService.GetTabelas();
_precos = ProdutosService.GetPrecos();

int codTabela = Params.CodTabela = Pedido.Cliente.CodProdPrecoTipo != 0 
    ? Pedido.Cliente.CodProdPrecoTipo 
    : _tabelas[0].Cod;

var query = from pr in _precos
    join prod in _produtos on pr.CodProduto equals prod.Cod
    where pr.CodProdPrecoTipo == codTabela
    select new Produto(prod, pr);

Hey everyone.

I've recently picked up Xamarin Forms to make a stream player app, but I've come across a problem that I can't seem to solve.
My problems are related to making implementing a video view within my app (Android specifically, I'm not focusing on iPhone at the moment).

The result I'm wanting to achieve is having a videoview together with webview taking 40% and 60% of vertical screen space respectively. While if the phone is rotated horizontally, filling the whole screen with only videoview taking all screen.

Basically what I'm trying to do is define my view as a grid with two rows and place a videoview and webview inside like this:

        <Grid
            x:Name="gridLayout"
            ColumnSpacing="0"
            RowSpacing="0">

            <Grid.RowDefinitions>
                <RowDefinition Height="40*" />
                <RowDefinition Height="60*" />
            </Grid.RowDefinitions>

            <controls:VideoPlayer
                VerticalOptions="StartAndExpand"
                HorizontalOptions="StartAndExpand"
                Grid.Row="0"
                AutoPlay="True"
                Source="{Binding StreamUrl, Mode=OneWay}" />

            <WebView
                Grid.Row="1"
                Source="{Binding HtmlSource, Mode=OneWay}" />
        </Grid>

The implementation of VideoView on Android follows the Microsofts' guide, with the exception of the VideoView being put in RelativeLayout with there paramaters:

LayoutRules.AlignParentLeft,
LayoutRules.AlignParentRight,
LayoutRules.AlignParentBottom,
LayoutRules.AlignParentTop,

as I want it to fill the whole screen space rather than being centered/match aspect ratio.

And the way I currently handle the rotation of screen to resize the elements:

protected override void OnSizeAllocated( double width, double height )
        {
            base.OnSizeAllocated( width, height );

            if( width > height ) {
                // Rotated horizontally
                gridLayout.RowDefinitions[ 0 ].Height = new GridLength( 100, GridUnitType.Star );
                gridLayout.RowDefinitions[ 1 ].Height = new GridLength( 0, GridUnitType.Absolute );
            }
            else {
                // Rotated vertically
                gridLayout.RowDefinitions[ 0 ].Height = new GridLength( 40, GridUnitType.Star );
                gridLayout.RowDefinitions[ 1 ].Height = new GridLength( 60, GridUnitType.Star );
            }
        }

When deploying on the android emulator which is running Android 8.1.2 or two of my phones where one is running 8.0.0 and 7.1.2 it produces the expected behaviour, but when deploying on my LG G4, which is running 6.0 when rotating the phone from vertical to horizontal the videoview will not fill the whole screen, but rather the same space as on vertical and afterwards, if phone is rotated again to vertical, it will zoom into the left corner of the videoview.

Here are screenshots of what is happening:
1) View is positioned vertically:
us.v-cdn.net/5019960/uploads/editor/d1/92pnge4sgzxi.png

2) Rotated horizontally:
us.v-cdn.net/5019960/uploads/editor/0y/zcc9k9pqlgbz.png

3) Rotated vertically again:
us.v-cdn.net/5019960/uploads/editor/5e/pustgdj7hauz.png

As you can see, initially if fills the whole space, but once rotated horizontally it will not fill anymore either vertically or horizontally and if the screen is rotated once again, the vertical view is now zoomed in to the left side.

I've been looking into this issue and it seems to be affecting other people as well (coincidencally with the exact same phone), as described in this Github issue: github.com/martijn00/XamarinMediaManager/issues/233

Since the first instinct with something like this is to blame your code so I went ahead and tried some of the available implementations on Github. One of these was github.com/adamfisher/Xamarin.Forms.VideoPlayer which produced the exact same broken behaviour.

Afterwards I gave a go with the ExoPlayer implementation (much appreciation for everyone that made bindings for it) here: github.com/martijn00/ExoPlayerXamarin and while it actually resized the videoview when rotating the screen I can't seem to make it fill the whole parent, where it rather keeps it in centrer and ignores Verical/HorizontalOptions of "StartAndExpand". The first implementation of VideoView (Microsofts') seem to also work properly when I specify the RelativeLayout paramaters as CenterInParent, but unfortunately that is not the effect I want to achieve.

In the end I tried to switch to RelativeLayout to see if it solved my issue, and unfortunately it produces the same effect.

So I'd wondered whether anyone else has had similar issues and if someone could help me solve this issue of getting VideoView to fit the whole allocated space and resizing properly when rotating the screen on all android devices. Or maybe point out the issues in my way of trying to resize the videoview when screen is rotated?

Much appreciated.

Recently some of my screens are behaving strangely.

On a page with five Pickers, Xamarin is focusing on the Pickers after the user finishes interacting with any of the other components. For example:

1. The user taps the first Picker on the Screen (Warehouses), and selects one of the items.
2. The user taps any other Picker on the Screen (for example, Yard), and selects one of those items.
3. As soon as the user selects the Yard Picker's item and the items disappear from the screen, the Warehouse Picker's items appear, as if the user tapped that picker.

This isn't a gamebreaker, but it definitely slows down the process. The items that appear on screen are almost always the Warehouse picker, given that it's the first one declared.

Any ideas on what might have caused this, or what can I do to fix it?

Snippet:

                        <Entry.Behaviors>
                            <b:EventToCommandBehavior EventName="Completed" Command="{Binding DurationCompletedCommand}"></b:EventToCommandBehavior>
                        </Entry.Behaviors>
                    </Entry>

Please let me know in case missed anything.

I have xamarin form application and followed https://github.com/Azure-Samples/active-directory-xamarin-native-v2 to implement Client Side Azure AD authentication. It is working fine.

For backed End Azure App Service, I have secured the app service using Authentication/Authentication menu and Express option. To test that , I created the
access token in postman : https://medium.com/agilix/getting-started-with-windows-azure-ad-authentication-using-postman-e37a185b642d and it is working fine.

Now, I want to integrate the xamarin form authentication with App Service. That means, If user have authenticated in Xamarin Form then the token should pass on to the app service in the background and work seamlessly. Please share your thoughts.

How to design a login page with material design using xamarin forms? Can any give the example source code?

2>Using "CompileToDalvik" task from assembly "C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Build.Tasks.dll".
2>Task "CompileToDalvik" (TaskId:419)
2> Task Parameter:DxJarPath=C:\LinkToAndroidSDK\build-tools\25.0.2\lib\dx.jar (TaskId:419)
2> Task Parameter:JavaToolPath=C:\LinkToJava8\bin (TaskId:419)
2> Task Parameter:JavaMaximumHeapSize=1024m (TaskId:419)
2> Task Parameter:ClassesOutputDirectory=obj\Debug\android\bin\classes (TaskId:419)
2> Task Parameter:MultiDexEnabled=False (TaskId:419)
2> Task Parameter:MultiDexMainDexListFile=obj\Debug\multidex.keep (TaskId:419)
2> Task Parameter:
2> JavaLibrariesToCompile=
2> C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\MonoAndroid\v7.1\mono.android.jar
2> obj\Debug__library_projects__\FormsViewGroup\library_project_imports\formsviewgroup.jar
2> obj\Debug__library_projects__\OkHttp\library_project_imports\okhttp-2.3.0-jar-with-dependencies.jar
2> obj\Debug__library_projects__\Xamarin.Android.Support.Animated.Vector.Drawable\library_project_imports\classes.jar
2> obj\Debug__library_projects__\Xamarin.Android.Support.Compat\library_project_imports\classes.jar
2> obj\Debug__library_projects__\Xamarin.Android.Support.Core.UI\library_project_imports\classes.jar
2> obj\Debug__library_projects__\Xamarin.Android.Support.Core.Utils\library_project_imports\classes.jar
2> obj\Debug__library_projects__\Xamarin.Android.Support.CustomTabs\library_project_imports\classes.jar
2> obj\Debug__library_projects__\Xamarin.Android.Support.Design\library_project_imports\classes.jar
2> obj\Debug__library_projects__\Xamarin.Android.Support.Fragment\library_project_imports\classes.jar
2> obj\Debug__library_projects__\Xamarin.Android.Support.Media.Compat\library_project_imports\classes.jar
2> obj\Debug__library_projects__\Xamarin.Android.Support.v4\library_project_imports\classes.jar
2> obj\Debug__library_projects__\Xamarin.Android.Support.v7.AppCompat\library_project_imports\classes.jar
2> obj\Debug__library_projects__\Xamarin.Android.Support.v7.CardView\library_project_imports\classes.jar
2> obj\Debug__library_projects__\Xamarin.Android.Support.v7.MediaRouter\library_project_imports\classes.jar
2> obj\Debug__library_projects__\Xamarin.Android.Support.v7.RecyclerView\library_project_imports\classes.jar
2> obj\Debug__library_projects__\Xamarin.Android.Support.Vector.Drawable\library_project_imports\classes.jar
2> obj\Debug__library_projects__\Xamarin.Azure.NotificationHubs.Android\library_project_imports\bin\classes.jar
2> C:\Users\richy\AppData\Local\Xamarin\Xamarin.GooglePlayServices.Ads\9.6.1\embedded\classes.jar
2> C:\Users\richy\AppData\Local\Xamarin\Xamarin.GooglePlayServices.Ads.Lite\9.6.1\embedded\classes.jar
2> C:\Users\richy\AppData\Local\Xamarin\Xamarin.GooglePlayServices.Base\9.6.1\embedded\classes.jar
2> C:\Users\richy\AppData\Local\Xamarin\Xamarin.GooglePlayServices.Basement\9.6.1\embedded\classes.jar
2> C:\Users\richy\AppData\Local\Xamarin\Xamarin.GooglePlayServices.Clearcut\9.6.1\embedded\classes.jar
2> C:\Users\richy\AppData\Local\Xamarin\Xamarin.GooglePlayServices.Gass\9.6.1\embedded\classes.jar
2> C:\Users\richy\AppData\Local\Xamarin\Xamarin.GooglePlayServices.Gcm\9.6.1\embedded\classes.jar
2> C:\Users\richy\AppData\Local\Xamarin\Xamarin.GooglePlayServices.Iid\9.6.1\embedded\classes.jar
2> C:\Users\richy\AppData\Local\Xamarin\Xamarin.GooglePlayServices.Tasks\9.6.1\embedded\classes.jar (TaskId:419)
2> Task Parameter:OptionalObfuscatedJarFile=obj\Debug\proguard__proguard_output__.jar (TaskId:419)
2> CompileToDalvik (TaskId:419)
2> JavaOptions: (TaskId:419)
2> JavaMaximumHeapSize: 1024m (TaskId:419)
2> ClassesOutputDirectory: obj\Debug\android\bin\classes (TaskId:419)
2> JavaToolPath: C:\LinkToJava8\bin (TaskId:419)
2> DxJarPath: C:\LinkToAndroidSDK\build-tools\25.0.2\lib\dx.jar (TaskId:419)
2> ToolExe: java.exe (TaskId:419)
2> ToolPath: (TaskId:419)
2> UseDx: False (TaskId:419)
2> MultiDexEnabled: False (TaskId:419)
2> MultiDexMainDexListFile: obj\Debug\multidex.keep (TaskId:419)
2> JavaLibrariesToCompile: (TaskId:419)
2> C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\MonoAndroid\v7.1\mono.android.jar (TaskId:419)
2> obj\Debug__library_projects__\FormsViewGroup\library_project_imports\formsviewgroup.jar (TaskId:419)
2> obj\Debug__library_projects__\OkHttp\library_project_imports\okhttp-2.3.0-jar-with-dependencies.jar (TaskId:419)
2> obj\Debug__library_projects__\Xamarin.Android.Support.Animated.Vector.Drawable\library_project_imports\classes.jar (TaskId:419)
2> obj\Debug__library_projects__\Xamarin.Android.Support.Compat\library_project_imports\classes.jar (TaskId:419)
2> obj\Debug__library_projects__\Xamarin.Android.Support.Core.UI\library_project_imports\classes.jar (TaskId:419)
2> obj\Debug__library_projects__\Xamarin.Android.Support.Core.Utils\library_project_imports\classes.jar (TaskId:419)
2> obj\Debug__library_projects__\Xamarin.Android.Support.CustomTabs\library_project_imports\classes.jar (TaskId:419)
2> obj\Debug__library_projects__\Xamarin.Android.Support.Design\library_project_imports\classes.jar (TaskId:419)
2> obj\Debug__library_projects__\Xamarin.Android.Support.Fragment\library_project_imports\classes.jar (TaskId:419)
2> obj\Debug__library_projects__\Xamarin.Android.Support.Media.Compat\library_project_imports\classes.jar (TaskId:419)
2> obj\Debug__library_projects__\Xamarin.Android.Support.v4\library_project_imports\classes.jar (TaskId:419)
2> obj\Debug__library_projects__\Xamarin.Android.Support.v7.AppCompat\library_project_imports\classes.jar (TaskId:419)
2> obj\Debug__library_projects__\Xamarin.Android.Support.v7.CardView\library_project_imports\classes.jar (TaskId:419)
2> obj\Debug__library_projects__\Xamarin.Android.Support.v7.MediaRouter\library_project_imports\classes.jar (TaskId:419)
2> obj\Debug__library_projects__\Xamarin.Android.Support.v7.RecyclerView\library_project_imports\classes.jar (TaskId:419)
2> obj\Debug__library_projects__\Xamarin.Android.Support.Vector.Drawable\library_project_imports\classes.jar (TaskId:419)
2> obj\Debug__library_projects__\Xamarin.Azure.NotificationHubs.Android\library_project_imports\bin\classes.jar (TaskId:419)
2> C:\Users\richy\AppData\Local\Xamarin\Xamarin.GooglePlayServices.Ads\9.6.1\embedded\classes.jar (TaskId:419)
2> C:\Users\richy\AppData\Local\Xamarin\Xamarin.GooglePlayServices.Ads.Lite\9.6.1\embedded\classes.jar (TaskId:419)
2> C:\Users\richy\AppData\Local\Xamarin\Xamarin.GooglePlayServices.Base\9.6.1\embedded\classes.jar (TaskId:419)
2> C:\Users\richy\AppData\Local\Xamarin\Xamarin.GooglePlayServices.Basement\9.6.1\embedded\classes.jar (TaskId:419)
2> C:\Users\richy\AppData\Local\Xamarin\Xamarin.GooglePlayServices.Clearcut\9.6.1\embedded\classes.jar (TaskId:419)
2> C:\Users\richy\AppData\Local\Xamarin\Xamarin.GooglePlayServices.Gass\9.6.1\embedded\classes.jar (TaskId:419)
2> C:\Users\richy\AppData\Local\Xamarin\Xamarin.GooglePlayServices.Gcm\9.6.1\embedded\classes.jar (TaskId:419)
2> C:\Users\richy\AppData\Local\Xamarin\Xamarin.GooglePlayServices.Iid\9.6.1\embedded\classes.jar (TaskId:419)
2> C:\Users\richy\AppData\Local\Xamarin\Xamarin.GooglePlayServices.Tasks\9.6.1\embedded\classes.jar (TaskId:419)
2> C:\LinkToJava8\bin\java.exe -Xmx1024m -jar C:\LinkToAndroidSDK\build-tools\25.0.2\lib\dx.jar --no-strict --dex --output=obj\Debug\android\bin obj\Debug\android\bin\classes "C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\MonoAndroid\v7.1\mono.android.jar" obj\Debug__library_projects__\FormsViewGroup\library_project_imports\formsviewgroup.jar obj\Debug__library_projects__\OkHttp\library_project_imports\okhttp-2.3.0-jar-with-dependencies.jar obj\Debug__library_projects__\Xamarin.Android.Support.Animated.Vector.Drawable\library_project_imports\classes.jar obj\Debug__library_projects__\Xamarin.Android.Support.Compat\library_project_imports\classes.jar obj\Debug__library_projects__\Xamarin.Android.Support.Core.UI\library_project_imports\classes.jar obj\Debug__library_projects__\Xamarin.Android.Support.Core.Utils\library_project_imports\classes.jar obj\Debug__library_projects__\Xamarin.Android.Support.CustomTabs\library_project_imports\classes.jar obj\Debug__library_projects__\Xamarin.Android.Support.Design\library_project_imports\classes.jar obj\Debug__library_projects__\Xamarin.Android.Support.Fragment\library_project_imports\classes.jar obj\Debug__library_projects__\Xamarin.Android.Support.Media.Compat\library_project_imports\classes.jar obj\Debug__library_projects__\Xamarin.Android.Support.v4\library_project_imports\classes.jar obj\Debug__library_projects__\Xamarin.Android.Support.v7.AppCompat\library_project_imports\classes.jar obj\Debug__library_projects__\Xamarin.Android.Support.v7.CardView\library_project_imports\classes.jar obj\Debug__library_projects__\Xamarin.Android.Support.v7.MediaRouter\library_project_imports\classes.jar obj\Debug__library_projects__\Xamarin.Android.Support.v7.RecyclerView\library_project_imports\classes.jar obj\Debug__library_projects__\Xamarin.Android.Support.Vector.Drawable\library_project_imports\classes.jar obj\Debug__library_projects__\Xamarin.Azure.NotificationHubs.Android\library_project_imports\bin\classes.jar C:\Users\richy\AppData\Local\Xamarin\Xamarin.GooglePlayServices.Ads\9.6.1\embedded\classes.jar C:\Users\richy\AppData\Local\Xamarin\Xamarin.GooglePlayServices.Ads.Lite\9.6.1\embedded\classes.jar C:\Users\richy\AppData\Local\Xamarin\Xamarin.GooglePlayServices.Base\9.6.1\embedded\classes.jar C:\Users\richy\AppData\Local\Xamarin\Xamarin.GooglePlayServices.Basement\9.6.1\embedded\classes.jar C:\Users\richy\AppData\Local\Xamarin\Xamarin.GooglePlayServices.Clearcut\9.6.1\embedded\classes.jar C:\Users\richy\AppData\Local\Xamarin\Xamarin.GooglePlayServices.Gass\9.6.1\embedded\classes.jar C:\Users\richy\AppData\Local\Xamarin\Xamarin.GooglePlayServices.Gcm\9.6.1\embedded\classes.jar C:\Users\richy\AppData\Local\Xamarin\Xamarin.GooglePlayServices.Iid\9.6.1\embedded\classes.jar C:\Users\richy\AppData\Local\Xamarin\Xamarin.GooglePlayServices.Tasks\9.6.1\embedded\classes.jar (TaskId:419)
2> (TaskId:419)
2> trouble writing output: Too many field references: 72871; max is 65536. (TaskId:419)
2> You may try using --multi-dex option. (TaskId:419)
2> References by package: (TaskId:419)
2> 2305 android.support.v4 (TaskId:419)
2> 13 android.support.v4.accessibilityservice (TaskId:419)
2> 17 android.support.v4.animation (TaskId:419)
2> 885 android.support.v4.app (TaskId:419)
2> 114 android.support.v4.content (TaskId:419)
2> 1 android.support.v4.content.pm (TaskId:419)
2> 1 android.support.v4.content.res (TaskId:419)
2> 11 android.support.v4.graphics (TaskId:419)
2> 41 android.support.v4.graphics.drawable (TaskId:419)
2> 4 android.support.v4.hardware.display (TaskId:419)
2> 12 android.support.v4.hardware.fingerprint (TaskId:419)
2> 10 android.support.v4.internal.view (TaskId:419)
2> 388 android.support.v4.media (TaskId:419)
2> 379 android.support.v4.media.session (TaskId:419)
2> 10 android.support.v4.net (TaskId:419)
2> 19 android.support.v4.os (TaskId:419)
2> 63 android.support.v4.print (TaskId:419)
2> 10 android.support.v4.provider (TaskId:419)
2> 55 android.support.v4.text (TaskId:419)
2> 6 android.support.v4.text.util (TaskId:419)
2> 118 android.support.v4.util (TaskId:419)
2> 434 android.support.v4.view (TaskId:419)
2> 138 android.support.v4.view.accessibility (TaskId:419)
2> 8 android.support.v4.view.animation (TaskId:419)
2> 495 android.support.v4.widget (TaskId:419)
2> 605 android.support.v7.app (TaskId:419)
2> 2305 android.support.v7.appcompat (TaskId:419)
2> 2305 android.support.v7.cardview (TaskId:419)
2> 8 android.support.v7.content.res (TaskId:419)
2> 18 android.support.v7.graphics.drawable (TaskId:419)
2> 437 android.support.v7.media (TaskId:419)
2> 2305 android.support.v7.mediarouter (TaskId:419)
2> 2305 android.support.v7.recyclerview (TaskId:419)
2> 1 android.support.v7.text (TaskId:419)
2> 2 android.support.v7.transition (TaskId:419)
2> 124 android.support.v7.util (TaskId:419)
2> 77 android.support.v7.view (TaskId:419)
2> 249 android.support.v7.view.menu (TaskId:419)
2> 1483 android.support.v7.widget (TaskId:419)
2> 89 android.support.v7.widget.helper (TaskId:419)
2> 1 android.support.v7.widget.util (TaskId:419)
2> 5 android.text (TaskId:419)
2> 1 android.text.util (TaskId:419)
2> 12 android.util (TaskId:419)
2> 19 android.view (TaskId:419)
2> 8 android.view.accessibility (TaskId:419)
2> 1 android.view.inputmethod (TaskId:419)
2> 5 android.webkit (TaskId:419)
2> 15 android.widget (TaskId:419)
2> 2299 app2.droid (TaskId:419)
2> 25 com.google.ads (TaskId:419)
2> 22 com.google.ads.mediation (TaskId:419)
2> 11 com.google.ads.mediation.customevent (TaskId:419)
2> 2299 com.google.android.gms (TaskId:419)
2> 20 com.google.android.gms.actions (TaskId:419)
2> 2342 com.google.android.gms.ads (TaskId:419)
2> 12 com.google.android.gms.ads.doubleclick (TaskId:419)
2> 19 com.google.android.gms.ads.formats (TaskId:419)
2> 13 com.google.android.gms.ads.identifier (TaskId:419)
2> 2299 com.google.android.gms.ads.impl (TaskId:419)
2> 256 com.google.android.gms.ads.internal (TaskId:419)
2> 22 com.google.android.gms.ads.internal.cache (TaskId:419)
2> 222 com.google.android.gms.ads.internal.client (TaskId:419)
2> 100 com.google.android.gms.ads.internal.formats (TaskId:419)
2> 158 com.google.android.gms.ads.internal.overlay (TaskId:419)
2> 51 com.google.android.gms.ads.internal.purchase (TaskId:419)
2> 197 com.google.android.gms.ads.internal.request (TaskId:419)
2> 14 com.google.android.gms.ads.internal.reward.client (TaskId:419)
2> 6 com.google.android.gms.ads.internal.reward.mediation.client (TaskId:419)
2> 6 com.google.android.gms.ads.internal.safebrowsing (TaskId:419)
2> 17 com.google.android.gms.ads.internal.util.client (TaskId:419)
2> 22 com.google.android.gms.ads.mediation (TaskId:419)
2> 1 com.google.android.gms.ads.mediation.admob (TaskId:419)
2> 12 com.google.android.gms.ads.mediation.customevent (TaskId:419)
2> 7 com.google.android.gms.ads.purchase (TaskId:419)
2> 1 com.google.android.gms.ads.reward.mediation (TaskId:419)
2> 46 com.google.android.gms.ads.search (TaskId:419)
2> 36 com.google.android.gms.auth.api.signin (TaskId:419)
2> 6 com.google.android.gms.auth.api.signin.internal (TaskId:419)
2> 2299 com.google.android.gms.base (TaskId:419)
2> 2345 com.google.android.gms.clearcut (TaskId:419)
2> 98 com.google.android.gms.common (TaskId:419)
2> 2393 com.microsoft.windowsazure.messaging (TaskId:419)
2> 342 com.squareup.okhttp (TaskId:419)
2> 86 com.squareup.okhttp.internal (TaskId:419)
2> 126 com.squareup.okhttp.internal.http (TaskId:419)
2> 1 com.squareup.okhttp.internal.io (TaskId:419)
2> 243 com.squareup.okhttp.internal.spdy (TaskId:419)
2> 11 com.squareup.okhttp.internal.tls (TaskId:419)
2> 1 com.xamarin.forms.platform.android (TaskId:419)
2> 25 java.lang (TaskId:419)
2> 7 java.lang.annotation (TaskId:419)
2> 1 java.math (TaskId:419)
2> 6 java.net (TaskId:419)
2> 1 java.nio (TaskId:419)
2> 6 java.util (TaskId:419)
2> 4 java.util.concurrent (TaskId:419)
2> 3 java.util.logging (TaskId:419)
2> 4 javax.microedition.khronos.egl (TaskId:419)

2> 4 mono.com.google.ads.mediation (TaskId:419)
2> 2 mono.com.google.ads.mediation.customevent (TaskId:419)
2> 4 mono.com.google.android.gms.ads.doubleclick (TaskId:419)
2> 8 mono.com.google.android.gms.ads.formats (TaskId:419)
2> 8 mono.com.google.android.gms.ads.mediation (TaskId:419)
2> 2 mono.com.google.android.gms.ads.mediation.customevent (TaskId:419)
2> 4 mono.com.google.android.gms.ads.purchase (TaskId:419)
2> 2 mono.com.google.android.gms.ads.reward (TaskId:419)
2> 2 mono.com.google.android.gms.ads.reward.mediation (TaskId:419)
2> 2 mono.com.google.android.gms.common.api (TaskId:419)
2> 2 mono.com.google.android.gms.common.images (TaskId:419)
2> 2 mono.com.google.android.gms.security (TaskId:419)
2> 6 mono.com.google.android.gms.tasks (TaskId:419)
2> 4 mono.java.lang (TaskId:419)
2> 2 mono.java.util (TaskId:419)
2> 2 mono.javax.xml.transform (TaskId:419)
2> 81 okio (TaskId:419)
2> 2 opentk (TaskId:419)
2> 2 opentk.platform.android (TaskId:419)
2> 2 opentk_1_0 (TaskId:419)
2> 2 opentk_1_0.platform.android (TaskId:419)
2>C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Common.targets(1965,3): error MSB6006: "java.exe" exited with code 2.
2> DexOutputs: (TaskId:419)
2>Done executing task "CompileToDalvik" -- FAILED. (TaskId:419)
2>Done building target "_CompileToDalvikWithDx" in project "App2.Droid.csproj" -- FAILED.: (TargetId:353)
2>
2>Project Performance Summary:
2> 42 ms \TF-RICHY\Aboo_share_win10\Backup\New app2 droid\App2 - Android\App2\App2\App2.csproj 3 calls
2> 34 ms GetTargetPath 1 calls
2> 1 ms GetNativeManifest 1 calls
2> 7 ms GetCopyToOutputDirectoryItems 1 calls
2> 189298 ms \TF-RICHY\Aboo_share_win10\Backup\New app2 droid\App2 - Android\App2\App2.Droid\App2.Droid.csproj 1 calls
2> 189298 ms Rebuild 1 calls
2>

2>
2>Build FAILED.
2>
2>Time Elapsed 00:03:09.29
========== Rebuild All: 1 succeeded, 1 failed, 0 skipped ==========

Hi all can someone please shed some light on creating Nuget packages for xamarin.forms

I'm currently looking into trying to make some Custom view controls / services's for Xamarin.Forms, has any one got helpful tips like from which starting project to setup and adding the proper config files such as the nuspec file in some step by step fashion.

I did use James Montemagno plugin https://marketplace.visualstudio.com/items?itemName=vs-publisher-473885.PluginForXamarinTemplates which i was able to generate the nuget package file but could install the nuget package in my project with an error

Could not install package ''. You are trying to install this package into a project that targets '.NETPortable,Version=v4.5,Profile=Profile111', but the package does not contain any assembly references or content files that are compatible with that framework.

So james plugin is also kinda old with no VS 2017 support and Xamarin moves so fast these days is this the preferred method developers follow?? I really wanna starting contributing some open source projects but where do i start.

Also whats up with NuGetizer 3000 can i use this? https://github.com/NuGet/Home/wiki/NuGetizer-3000 - The goal of the NuGetizer 3000 project is to make it as easy as possible to create and publish a NuGet package, including bait-and-switch packages, and provide guidance to users along the way.

I'm using a window 10 machine with VS 2017 but also setup VS 2015 for Jame's plugin

Hello,
any idea how to make a Tabbed view in xamarin.forms,
i only found Tabbed page which is not possible to put it inside a content page!

choosing Xamarin.forms is bad choice? should i've used each platforme beside with xamarin.android and xamarin.ios!

Thanks in advance

First, Aren't ContextAction's available in UWP at all?

Second, I see the sliding for ContextAction buttons be visible is available in iOS only. Can't we get sliding for actions in Android?

Third, In iOS they appear only on sliding from right to left. I don't find any property to set to make them appear while sliding from left to right?

How can I get around these two issues?

Hi, i want to keep entry value which i type in entry box then i go another page and then went back to the main page where previously i type somethings in entry box. Now how i keep those data without save in local database.

I wanted to use double-tap on a ListViewItem. Since there is no DoubleClicked event defined for ListView, I wanted to use the TapGestureRecognizer with NumberOfTapsRequired = 2.

It works fine in iOS & UWP but not in Android. What am I doing wrong?

Hello. I am a new Xamarin Forms developer and actually a new programmer. I am trying to add a map into an app and I'm using the Xamarin Forms Google Maps NuGet. Installed it but when I try to open the page which has the XAML code for the map, the app enters a break mode. I tried different things and different code from the sample app, but still nothing else happens. The bad things is that I do not know why. Can anyone help?
This is the simplest code I tried running.

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

<ContentPage.Content>

    <maps:Map x:Name="map"></maps:Map>

</ContentPage.Content>

Hi to all.
I want to make a Hamburger menu just like alliexpres one.

Is this possible starting with Visual Studio Master-Detail example.

Thanks in advance

hi

when i create new basic android app via xmarin and create listview with items in it i can automatically scroll the items via bluetooth keyboard
but when i create the same under xamarin.forms app i am not able to scroll using the bluetooth keyboard

is it a bug? i have to code it?

please advice i really stuck here

thanks.

Hi,

I am trying to build a XF project but getting the following weird error:

3>C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\MSBuild\Xamarin\Android\Xamarin.Android.Common.targets(2129,5): error MSB4018: The "LinkAssemblies" task failed unexpectedly.
3>C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\MSBuild\Xamarin\Android\Xamarin.Android.Common.targets(2129,5): error MSB4018: Mono.Linker.MarkException: Error processing method: 'System.Void WiFiManager.MainPage::InitializeComponent()' in assembly: 'WiFiManager.dll' ---> Mono.Cecil.ResolutionException: Failed to resolve System.Void Xamarin.Forms.Xaml.Internals.SimpleValueTargetProvider::.ctor(System.Object[],System.Object,Xamarin.Forms.Internals.INameScope)

The full list is available here:
https://pastebin.com/k4hTDVTQ

What am I doing wrong?

I guess before I start let me say I love the support from the Microsoft Xamarin Support Team and have high hopes that we can move past some of the issues we have run into using Xamain. I work with 5 other developers and started using Xamarin a couple of years ago. We are obviously a Microsoft shop and we came into mobile green – very very green. We were used to developing in Visual Studio and knocking out web applications with no problems at all. The boss gives a request, no problem, we knocked it out. Xamarin was an obvious toolset when we chose to start doing mobile development with all of us skilled in C# and the whole idea of coding once. We knew we needed a mac mini so we went out and bought 1 for the team of five. This was a bit of a change from web development where we had all our tools locally with VS on Windows, but hey this is mobile development which includes iOS so we moved forward. Just setting it up and getting VS to talk to the mac mini was an interesting endeavor, to say the least. We quickly found out sharing a mac mini wasn’t going to cut it. Each of us would need our own mac mini on our desks. I told you we were green right? Okay, no problem. Next, the current laptops we had were continuously putting VS in busy mode…chugging and choking as it attempted to build our projects. New more powerful laptops were needed. No problem. It was just the nature of what I started to call “The Beast”. Next one by one each developer started commenting on how long it took to make a small change and test it out on the droid and iOS simulators. What was this all about? In our past web development, we had NEVER seen this type of poor performance. Okay, it’s slow. It’s a different beast and we’ll just have to deal with it. We keep moving forward. So we’re going along with our new tool and we are thinking we’re starting to figure out this whole toolset when BAM it just stops working accordingly. Here’s a couple of scenarios.s The boss gives you a simple change like change this text and color on this page. Wow – no problem at all. Everything was working fine on my box yesterday with VS/Xamarin, so I’m none the wiser when all of sudden today when I have this deliverable it starts to flake out. I make the coding change, run it, and it just sits there in build mode. Build…build…building - like not ever finishing. I start googling this and find out…oh, sometimes this happens with Xamarin. When this happens try a clean, close out VS, delete the bin and obj folders, start VS, and try again. What the heck? I’m starting to realize I don’t have the Beast figured out. I follow the instructions and magically enough it works. Okay. Weird but I keep moving forward. A few days go by with no problems in Xamarin land. The building and launching vary from 2 minutes to 7 minutes, but at this point, I’m just glad it launches. The boss then requests a new page. No problem. Fire up my toolset, make the change, and again building building… I’ve seen this issue before and now know the solution. I follow my crazy steps above but this time no success. What? I try the steps again. No luck. I add one more step -> reboot pc. It works. Omg. So at this point, I’m getting a little concerned. I’ve got simple requests, but I can’t always count on Xamarin in a timely manner. It comparable to reaching for a drill out of your toolbox and expecting it to drill a hole each time, but sometimes it doesn’t work and you have to take the drill bit out, put it back in, unplug the cord, plug it back in, pray to the tool gods, and hope like it hell it starts working. Any sane person would just buy another drill. Obviously, that’s not an option for us and I’m not bringing that up. This is where we are at now. And to top it off after finally getting emulators/simulators working, they're not playing nice consistently and I’ve been burned enough to know to attach an actual device is the best method because sometimes what you see/experience with them is NOT what you see/experience when you deploy to actual devices.

We can’t be the only ones struggling? How can we provide an estimate of hours of work required when we can’t depend on the tool working accordingly? I know many will reply with suggestions which I welcome and deeply appreciate. I guess I’m also just looking for a little bit of an Amen, you’re preaching to the choir? I’d also be interested to know if it works “smoothly” CONSISTENTLY for others? Thanks for your time reading and your feedback.