I created a custom data template for GridView Generated Items in my UWP app. It includes text block and image object. I'm planning change ImageSource according to the TexBlock.Text value..

     <Interactivity:Interaction.Behaviors>      
                        <Core:DataTriggerBehavior>
                            
                                <Core:ChangePropertyAction/>
                        </Core:DataTriggerBehavior>
                        </Interactivity:Interaction.Behaviors>

After that, I installed "Behaviors.Managed for UWP by Microsoft" from GitHub for creating some behaviors in my template. I drag&drop "ChangePropertyAction" to image control in my template. However, this error occurred in XAML designer:

The 'DataTriggerBehavior' does not support direct content. - Implicit_items is null.

I opened a topic in MSDN Forums about this issue. MSFT David FF suggests adding an extra code manually "Core:EventTriggerBehavior.Actions" like this:

                        <Interactivity:Interaction.Behaviors>
                           
                        <Core:DataTriggerBehavior>
                            <Core:DataTriggerBehavior.Actions>
                                <Core:ChangePropertyAction></Core:ChangePropertyAction>
                                    
                            </Core:DataTriggerBehavior.Actions>
                        </Core:DataTriggerBehavior>
                        </Interactivity:Interaction.Behaviors>

Unfortunately, I' m getting same error in Blend and VS while adding some extra code manually.
However, I do not get this error if I use behaviors on a control in my MainPage.xaml without using any template. Debugger shows an error if I drag&drop an behavior item to a control, but XAML editor running perfectly without any error and building finished successfully. I think that this bug caused from the Behaviors SDK. It looks needs a repair.

Thanks.

It happens sometimes, cannot repro deterministically.

Other people may have similar issues
jlaanstra/Windows.UI.Interactivity#13

If one page's NavigationCacheMode set to Required and use the NavigationToPageAction, navigate to other page by NavigationToPageAction, go back and navigate again, the back stack will repeat.

The demo link is here:
http://1drv.ms/1NpIPkV

And sorry for my terrible English.

<DoubleAnimation Duration="0:0:2.2" To="0.35"
    Storyboard.TargetProperty="(UIElement.RenderTransform).(CompositeTransform.ScaleY)"
    Storyboard.TargetName="StoryboardRectangle" 
    d:IsOptimized="True"/>

Google and Bing not helped.

Visual Studio upd 2

I just cloned the uwp behaviors project from github.
Did a build of the Managed version and then tried to build the samples and all I got was this:

C:\Projects\GitHub\XamlBehaviors\samples\CS\XAMLBehaviorsSample\CallMethodControl.DeviceFamily-Mobile.xaml(60,85): XamlCompiler error WMC0610: XBF generation error code 0x07da.

Any idea why? it's on line <Interactions:CallMethodAction TargetObject="{Binding}" MethodName="IncrementCount"/>

If I remove this I get another error later on:

C:\Projects\GitHub\XamlBehaviors\samples\CS\XAMLBehaviorsSample\ChangePropertyControl.DeviceFamily-Mobile.xaml(64,146): XamlCompiler error WMC0615: Type 'StaticResource' used after '{' must be a Markup Extension. Error code 0x07da.

On this line <Interactions:ChangePropertyAction TargetObject="{Binding ElementName=DataTriggerRectangle}" PropertyName="Fill" Value="{StaticResource PaleYellowBrush}"/>

Anyway... so I'm unable to build said project

TypeConverterHelper.Convert cannot convert double value in the language of which is comma (,) decimal point. (e.g. Deutsch) Its methods is dependent on OS culture (see below). Is this behavior bug, or by design?

I also confirmed Windows Phone 8.1 version Behavior SDK.

// Value types in the "System" namespace must be special cased due to a bug in the xaml compiler
if (string.Equals(scope, "System", StringComparison.Ordinal))
{
  ...
  else if (string.Equals(destinationTypeFullName, typeof(double).FullName, StringComparison.Ordinal))
  {
    return double.Parse(value, CultureInfo.CurrentCulture); // ← HERE!
  }
}

https://github.com/Microsoft/XamlBehaviors/blob/858fc2b954635e3280f1eeb634773320ecc5cc58/src/BehaviorsSDKManaged/Microsoft.Xaml.Interactions/Core/TypeConverterHelper.cs#L51

Add symbols and source to symbolsource.org. Add documentation comments too.

When using attaching an Action to a uielement inside a datatemplate and viewing in xaml designer the code will throw the error Collection property '__implicit_items' is null. This would lead me to think I have to initialize behaviors/Actions collection before adding actions however, you still get the same error. The error is only thrown at design time and compiles and runs as expected.

This only occurs when the action is added to an element inside a datatemplate and it disables further designing of the template. This can be duplicated in both Visual studio and Blend.

Code:
<Interactivity:Interaction.Behaviors> <Core:EventTriggerBehavior EventName="Tapped"> <Core:NavigateToPageAction TargetPage="" /> </Core:EventTriggerBehavior> </Interactivity:Interaction.Behaviors>

Additional Information:
This does not happen until you attempt to enter design view. so you have to click edit generated items(itemtemplate) from the document outline.

Hello,
i have this error message in debug mode, in runtime works well.
I try sample in two different computer, but i got the same error message in the error window.
my base sample is :

xmlns:Interactivity="using:Microsoft.Xaml.Interactivity"
xmlns:Core="using:Microsoft.Xaml.Interactions.Core"

    <Button Content="CLICK ME" Margin="0,10,0,0" VerticalAlignment="Top">
        <Interactivity:Interaction.Behaviors>
              <Core:EventTriggerBehavior EventName="Click">
                <Core:ChangePropertyAction PropertyName="Background">
                    <Core:ChangePropertyAction.Value>
                        <SolidColorBrush Color="#FFE02B2B"/>
                    </Core:ChangePropertyAction.Value>
                </Core:ChangePropertyAction>
            </Core:EventTriggerBehavior>
        </Interactivity:Interaction.Behaviors>
    </Button>

I have europe time zone and vb.net template.

do you have some recommendation for my case.

with best regards

AL

Hello,
I have hit a wall when trying to debug my app on phone. Everything worked well before, but now for some unknown reason each time I start my app on the phone it crashes with the following outpput:

Exception thrown: 'System.TypeLoadException' in Vtipnik.Client.WindowsUniversal.exe
'Vtipnik.Client.WindowsUniversal.exe' (CoreCLR: CoreCLR_UWP_Domain): Loaded 'C:\Data\SharedData\PhoneTools\AppxLayouts\c024fabb-341d-47d4-b8f2-054ac59096f8VS.Debug_ARM.marti\System.Resources.ResourceManager.dll'. Module was built without symbols.
Exception thrown: 'Windows.UI.Xaml.Markup.XamlParseException' in Vtipnik.Client.WindowsUniversal.exe
WinRT information: Cannot deserialize XBF metadata property list as 'Behaviors' was not found in type 'Microsoft.Xaml.Interactivity.Interaction'. [Line: 0 Position: 0]

The only place where Interactions are on the main page is the following:

        <interactivity:Interaction.Behaviors>
            <core:EventTriggerBehavior EventName="PointerReleased">
                <core:ChangePropertyAction PropertyName="IsPaneOpen" TargetObject="{Binding ElementName=SplitViewCore}" Value="{Binding ElementName=SplitViewCore, Path=IsPaneOpen, Converter={StaticResource BooleanNegationConverter}}" />
            </core:EventTriggerBehavior>
        </interactivity:Interaction.Behaviors>

I really have no idea what is wrong, I have tested the exact same code in a different blank app and it works so I am really confused...

Thank you for any ideas or directions

Hello,
I just have tested the sample and I would like to know if it is possible to combine the DragPositionBehaviors with a solution allowing to resize the shapes?
On my UWP app, I must allow users to add an basic shape on a photo, and then let them resizing and moving this shape on the photo...
Thanks in advance,

The current design doesn't have a contract for a trigger style behavior now that both triggers and behaviors have been merged into one.

This affects any framework that works with triggers in abstract (such as Caliburn.Micro) where the following is not possible.

IBehavior trigger = CreateTrigger();
IAction action = CreateAction();

trigger.Actions.Add(action);

I propose adding a new interface

public interface ITriggerBehavior : IBehavior
{
    ActionCollection Actions { get;}
}

and applying to this to the out of the box triggers.

Thoughts?

Can I set a value in a ViewModel reacting to an Event in the View?

For instance, when a WebView control starts loading content, the ContentLoading  event is invoked.
When it has finished loading the content, the LoadCompleted event is invoked.

I would like to have a property in my ViewModel that is set to true/false when those events are raised. For example, a IsLoading property.

Then, I could show a ProgressRing when appropriate.

Hi,
Is it possible to use event arguments as parameter for commands when using InvokeCommandAction?!
Actually I'm using ItemClick event with behaviors on a ListView & ItemClickEventArgs is the only way to know which item clicked.
Maybe It's good to notice for a reason I can't use SelectedItem, because It's null when you set SelectionMode="None" & also that I'm developing UWP app in C#.

Thanks

The AssociatedObject property on the Behavior class has the EditorBrowsable attribute set to Never so you will never be able to access AssociatedObject via intellisense. The property should be allowed to be accessed via intellisense.

Thanks to @meldim for pointing this out.

The link in this section https://github.com/Microsoft/XamlBehaviors/wiki#using-behaviors-sdk points to the wiki itself, not the correct location.

I cannot get the following DataTriggerBehavior to work with a nullable type; e.g.
double? MyValue = null;

                        <i:Interaction.Behaviors>
                            <ic:DataTriggerBehavior Binding="{Binding MyValue}" Value="{x:Null}" >
                                <ic:ChangePropertyAction PropertyName="Foreground" Value="Red"/>
                            </ic:DataTriggerBehavior>
                        </i:Interaction.Behaviors>

The foreground never turns Red.

Normally when trying to force an update with a binding I just raise the event of the INotifyPropertyChanged and the binding is forced updated, however when trying this to trigger the datatriggerbehavior like this it does not work untill I really have a different value.
For example I want to get the value when triggered and then with an action put it into textfield like a little log or invoke a command in the view despite being the same every time.

The request is that the row of my ListView blinks when the property SelectedItem of the ViewModel raises change.

This is my code, the problem is that it works only first time SelectedItem became true.

<DataTemplate x:Key="myDataTemplate">
    <Grid x:Name="myGrid">
        <Interactivity:Interaction.Behaviors>
            <Core:DataTriggerBehavior Binding="{Binding SelectedItem}" Value="True">
                <Media:ControlStoryboardAction>
                    <Media:ControlStoryboardAction.Storyboard>
                        <Storyboard>
                            <ColorAnimation
                                To="#009ABF" 
                                Storyboard.TargetName="myGrid" 
                                Storyboard.TargetProperty="(Grid.Background).(SolidColorBrush.Color)" 
                                AutoReverse="True" 
                                Duration="0:0:1"
                                RepeatBehavior="1x" />
                        </Storyboard>
                    </Media:ControlStoryboardAction.Storyboard>
                </Media:ControlStoryboardAction>
            </Core:DataTriggerBehavior>
        </Interactivity:Interaction.Behaviors>
        <!--OMISSIS-->
</Grid>

See detail here

Is this intended behavior?

Consider the following:

<interactivity:Interaction.Behaviors>
    <interactions:DataTriggerBehavior Binding="{x:Bind Vm.IsLiked, Mode=OneWay}" Value="False">
        <interactions:GoToStateAction StateName="NotLiked"/>
    </interactions:DataTriggerBehavior>
    <interactions:DataTriggerBehavior Binding="{x:Bind Vm.IsLiked, Mode=OneWay}" Value="True">
        <interactions:GoToStateAction StateName="Liked"/>
    </interactions:DataTriggerBehavior>
</interactivity:Interaction.Behaviors>

The visual state won't be set correctly until Vm.IsLiked actually changes value.

If this is intended behavior, then what is the best way for me to trigger an evaluation? Should I raise a property changed event for IsLiked in my view model at some point? I can't do it in the VM's constructor because there are no registered listeners yet.

See: line 91 of EventManager.cpp. This exact list also exists in Bliss's EventPickerEditor.xaml.cs because we don't want our code to depend on the external SDK. The ideal fix for this should be putting the list in the design-time assembly and having both the EventPickerEditor and the EventManager source the list from there.

Haven't had a chance to look into the cause yet, but there is a bug where the EventTriggerBehavior is interacting incorrectly with the popup secondary commands menu of a CommandBar.

I've put up a quick sample of the bug, but the basics are that it appears the behavior is attached to the click event every time the menu is opened. Therefore when the button is clicked the accompanying action is invoked as many times as the menu was opened previously.

XamlBehaviors are really powerfull and more lately noticed that some designers are going faster with productivity with the more small components made into it. But we are running into some small behaviors/actions issue when it comes to actions that require async/await.

A common scenario that we have is that the we have a lot of small actions that help the designers just plug in the feature where needed and out later instead of in code, this really sped up a lot of implementations and requirements but we are having issues when the designers need to do few actions in a row. For example assume there are 3 actions required to be executed but the second one is a IO operation with Async execute only that you either need to await or .Wait/Result and the third action relies on it. Currently you now either perform a blocking UI action while you want fluent UI or do in code behind (and dozen of places).

I would like to propose an addition of an IAwaitableAsync with the method Task Execute(object sender, object parameter);
SideNote: Maybe even introduce a base class like with Behavior, one named BehaviorAction and AwaitableBehaviorAction

There are few critical changes that would be required though, like the Interaction.ExecuteActions would have to do a blocking support or replaced by a new method named Interaction.ExecuteActionsAsync.
All Behaviors of the package would have to use that method to support Async/Await.
CallMethodAction should also ignore the check if a method returns nothing to match the perfect signature and in case it returns a Task it should await it.

After upgrading the nuget package from 1.0.3 to 1.1.0 I cannot compile!

Strongname signing of assemblies as well as potential Authenticode signing.

Is there a new release on this going to be put out soon? I'm living with behaviors everyday in my day job, and #108 is the most aggravating thing in my life right now (AssociatedObject? Intellisense is having none of it!), so it would be much lovely if it could be pushed to NuGet sometime soon.

I ran into a strange error using a custom DataGrid control for UWP. The control implemented it's own SelectionChanged event, basing it on the SelectionChangedEventHandler from System.Windows.Controls.

The text associated with this error code could not be found.

Cannot add instance of type 'Microsoft.Xaml.Interactions.Core.EventTriggerBehavior' to a collection of type 'Microsoft.Xaml.Interactivity.BehaviorCollection'. [Line: 148 Position: 102]

This happened because the EventTriggerBehavior attempted to handle the event with WindowsRuntimeMarshal.AddEventHandler.

Xaml looks something like this:

<mytkctl:DataGrid ItemsSource="{Binding Entries}" Name="WeightGrid">
    <Interactivity:Interaction.Behaviors>
        <Core:EventTriggerBehavior EventName="SelectionChanged" >
            <Core:InvokeCommandAction 
            Command="{Binding EntrySelectionChanged}" 
            CommandParameter="{Binding Path=SelectedItem, ElementName=WeightGrid}" />
        </Core:EventTriggerBehavior>
    </Interactivity:Interaction.Behaviors>
    <mytkctl:DataGrid.Columns>
        <mytkctl:DataGridTextColumn Header="Date" Binding="{Binding Date}" />
        <mytkctl:DataGridTextColumn Header="Weight" Binding="{Binding StringWeight}" />
    </mytkctl:DataGrid.Columns>
</mytkctl:DataGrid>

After figuring out the issue, I was able to resolve it fairly easily in the MyToolkit library, by downloading the source and adding a local copy of the SelectionChangedEventHandler delegate...

public delegate void SelectionChangedEventHandler(System.Object sender, SelectionChangedEventArgs e);

The question is how common is this issue? Is this something that all custom control libraries should watch out for? Or is this something that can be fixed in XamlBehaviors?

It seems that binding DataTriggerBehavior to enum property on a viewmodel doesn't work and breaks other bindings in page/usercontrol too.

I'm trying to bind DataTriggerBehavior to an enum property on a viewmodel and compare it to a string representation of the enum value.

It seems there is no official up-to-date package that would provide the same functionality for WPF.

Update:
https://blogs.windows.com/buildingapps/2015/11/30/xaml-behaviors-open-source-and-on-uwp
http://www.infoq.com/news/2016/02/XAML-Behaviors

As of right now, XAML Behaviors have not been open sourced for WPF. However, we would like to continue to grow Behaviors. Cross-platform XAML Behaviors for things like WPF is definitely on the roadmap, and if there is interest from the community we would definitely like to bring new Behaviors to WPF in the future.

@jonwchu there is definitely an interest from the community.

http://visualstudio.uservoice.com/forums/121579-visual-studio-2015/suggestions/5282131-open-source-behaviors-sdk-xaml-for-visual-studio

In all XAML Based technologies we use Behaviors all the time, on...

@unniravindranathan the UserVoice suggestion was unfortunately marked as "Completed" without providing WPF support.

I am using "EventTriggerBehavior", basically
object IAction.Execute( object sender, object parameter ) for determining which page to navigate depending upon the where the click is coming form. In UWP Apps, when the configuration is Debug mode, everything seems to be working fine but when the configuration is Release mode, the parameter for ClickedItem is coming null.

In DragPositionBehavior.cs after pointer is pressed RenderTransform will be replaced by TranslateTransform. That is bad. Because if we have already changed it for example to ScaleTransform or CompositeTransform it will be replaced and we can't using old version.

Let the source page define an event behavior with a CallMethodAction. Now, when we navigate to another page and back to source page, there are two method calls registered against the said event. This issue only occurs when the source page has NavigationCache set to Enabled or Required. My guess is that the sdk keeps attaching more and more method calls against the event every time we navigate to source page. Is there any way to work around this?
I have more specific question here on StackOverflow.

While building a UWP app I have noticed a very unusual behavior with ControlStoryboardAction running on Anniversary Update PCs.

Code sample

<ListView ItemsPanel="{StaticResource HorizontalPanel}" ItemsSource="{x:Bind Items}">
     <ListView.ItemTemplate>
         <DataTemplate>
             <Border x:Name="Container">
                 <Border.Background>
                     <SolidColorBrush Color="Transparent" />
                 </Border.Background>
                 <Border.Resources>
                     <Storyboard x:Key="BlinkingAnimation" RepeatBehavior="Forever" AutoReverse="True">
                         <ColorAnimation Duration="0:0:1" To="Red" Storyboard.TargetProperty="(Grid.Background).(SolidColorBrush.Color)" Storyboard.TargetName="Container">
                         </ColorAnimation>
                     </Storyboard>
                  </Border.Resources>
                  <StackPanel VerticalAlignment="Center">
                     <TextBlock Text="Is animating:" FontWeight="Bold" HorizontalAlignment="Center" />
                     <TextBlock VerticalAlignment="Center" HorizontalAlignment="Center" Text="{Binding IsAnimating}" />
                   </StackPanel>
                   <interactivity:Interaction.Behaviors>
                       <core:DataTriggerBehavior 
                                Binding="{Binding IsAnimating, Mode=OneWay}" 
                                ComparisonCondition="Equal"
                                Value="true">
                                <media:ControlStoryboardAction ControlStoryboardOption="Play" Storyboard="{StaticResource BlinkingAnimation}" />
                       </core:DataTriggerBehavior>
                       <core:DataTriggerBehavior 
                                Binding="{Binding IsAnimating, Mode=OneWay}" 
                                ComparisonCondition="Equal"
                                Value="false">
                                <media:ControlStoryboardAction ControlStoryboardOption="Stop" Storyboard="{StaticResource BlinkingAnimation}" />
                        </core:DataTriggerBehavior>
                 </interactivity:Interaction.Behaviors>
             </Border>
        </DataTemplate>
    </ListView.ItemTemplate>
</ListView>

Download sample

You can download the sample solution here:
AnimationInDataTemplateProblem.zip

Expected behavior

When I set Items[2].IsAnimating = true, the third item in the ListView should start animating its border's background.

Actual behavior

The actual behavior is in line with expectations on PCs and phones running 10586 (November update) and 15063 (Creators Update). However, on 14393 (Anniversary Update) whichever item's IsAnimating property is set, the storyboard always runs on the first item in the list. In fact, stepping through the code it seems that each ControlStoryboardAction has set the first item's Storyboard, which it then manipulates.

Interesting thing to note is that compiling the app against different SDK versions has no effect. Whether the app's target SDK is NU, AU or CU, the results are always the same.

Workaround

The only workaround I have found so far is to wrap the contents of the DataTemplate into a UserControl (this approach is also demonstrated in the sample solution), which works consistently everywhere. Still it is a very strange problem and I think it warrants investigation (also because AU is currently the most widely used version of W10).

I have written a simple NavigateBackAction behavior, see https://gist.github.com/sonnemaf/0d1c6fbc3cfc4e2310c4 You can use it to implement a GoBack() navigation on a Frame.

I would like to include it in the project but this might not be a good idea. Instead of adding this behavior we could change the implementation of the NavigateToPageAction by adding a 'NavigationType' (enum: Page, Backward, Forward, ClearBackstack?) property to it. The name of the NavigateToPageAction might also have to change.

What should we do? Do we want many small/simple behaviors or do we create bigger/smarter ones with many options?

Fons

I think there should be a gitter room for people looking forward to learn these things and want to know some things and discuss things !!

Recently I update my app to use the nuget version of Behaviors (this repo). My app stop changing VisualState when property changed.

Here is the code:

<i:Interaction.Behaviors>
        <core:DataTriggerBehavior Binding="{Binding HeaderLoaded}"
                                  ComparisonCondition="Equal"
                                  Value="True">
            <core:GoToStateAction StateName="HeaderLoaded"
                                  TargetObject="{Binding ElementName=root}"
                                  UseTransitions="True" />
        </core:DataTriggerBehavior>
        <core:DataTriggerBehavior Binding="{Binding HeaderLoaded}"
                                  ComparisonCondition="NotEqual"
                                  Value="True">
            <core:GoToStateAction StateName="Default"
                                  TargetObject="{Binding ElementName=root}"
                                  UseTransitions="False" />
        </core:DataTriggerBehavior>
</i:Interaction.Behaviors>

I navigate to the page, Visual state changes to HeaderLoaded, I go back, it changes to Default. After that, it remains Default, despite that HeaderLoaded changes to true.
In short, Visual state never be changed after navigating from the Page.

Hi
For some reason the Behavior list in Blend does not populate the "latest and greatest" behaviors after installing the nuget package.
Any ideas why it doesnt?

I have an ItemsControl which displays two different types of items (using ContentPresenter/Caliburn.Micro). When I add the first item that causes a scrollbar to appear, I'm seeing OnDetaching get called:

>	BindableFocusBehavior.OnDetaching() Line 84	C#
 	Microsoft.Xaml.Interactivity.dll!Microsoft.Xaml.Interactivity.Behavior.Detach()	Unknown
 	Microsoft.Xaml.Interactivity.dll!Microsoft.Xaml.Interactivity.BehaviorCollection.Detach()	Unknown
 	Microsoft.Xaml.Interactivity.dll!Microsoft.Xaml.Interactivity.Interaction.FrameworkElement_Unloaded(object sender, Windows.UI.Xaml.RoutedEventArgs e)	Unknown

Each item I add after that causes OnAttached/OnDetaching to get called on the same BindableFocusBehavior instance, which leaves AssociatedObject null.

>	BindableFocusBehavior.OnAttached() Line 90	C#
 	Microsoft.Xaml.Interactivity.dll!Microsoft.Xaml.Interactivity.Behavior.Attach(Windows.UI.Xaml.DependencyObject associatedObject)	Unknown
 	Microsoft.Xaml.Interactivity.dll!Microsoft.Xaml.Interactivity.BehaviorCollection.Attach(Windows.UI.Xaml.DependencyObject associatedObject)	Unknown
 	Microsoft.Xaml.Interactivity.dll!Microsoft.Xaml.Interactivity.Interaction.FrameworkElement_Loaded(object sender, Windows.UI.Xaml.RoutedEventArgs e)	Unknown

I'm not sure why the ItemsStackPanel is repeatedly loading/unloading the same UserControl, but is it possible that the events are being handled in the wrong order?

My workaround is currently just to store the AssociatedObject to a private field.

Currently, the tooling description strings live in a sealed resx within Bliss. This makes these strings difficult (if not impossible) to access from the SDK and makes further work to localize or edit them impossible. Thus, they should be moved out of Bliss and into a local package resource file.

NavigateToPageAction.Execute has a loop (see below) where it checks if the sender implements INavigate and if not works its way up the visual tree looking for the first INavigate ancestor. However, there's a typo in this loop where every time around the loop it's checking if sender (the original sender parameter) implements INavigate rather than checking senderObject (the ancestor). So if the sender parameter is not an INavigate, Execute always fails.

87 DependencyObject senderObject = sender as DependencyObject;
88
89 // If the sender wasn't an INavigate, then keep looking up the tree from the
90 // root we were given for another INavigate.
91 while (senderObject != null && navigateElement == null)
92 {
93 navigateElement = sender as INavigate;
94 if (navigateElement == null)
95 {
96 senderObject = VisualTreeHelper.GetParent(senderObject);
97 }
98 }
99
100 if (navigateElement == null)
101 {
102 return false;
103 }

Identify localization process and potentially port existing Behaviors SDK localized resources.

Hi,
I'm using the latest Nuget version, 1.0.3, managed.
My projects has french resources, in a /Resources/fr/resources.resw file.
When I submit my project to the store, it wants me to add a description for the fr-FR language, which is not correct because I don't explicitly support it.
When I remove the XamlBehaviors package it doesn't ask me for an extra language, which is the expected behaviour.
I already tried this solution : http://metronuggets.com/2015/12/03/got-unexpected-extra-languages-in-your-uwp-store-submission/ but it doesn't solve anything.
Any idea about this ?

Regards,

I have noticed that when using EventTriggerBehavior with SourceObject="{x:Bind ...} you must always have an event name that is available in the parent container even if you define because otherwise it will throw an exception as followed:

Cannot add instance of type 'Microsoft.Xaml.Interactions.Core.EventTriggerBehavior' to a collection of type 'Microsoft.Xaml.Interactivity.BehaviorCollection'.

This is because when using {x:Bind ...} the Behavior will set the resolvedSource internally to the parent container, which is resolved by the parent class Behavior because {x:Bind ...} is used.
If you use {Binding ...} this problem will not occur and therefor workaround till the {x:Bind ...} is supported.

The root cause of this is the SourceObjectProperty PropertyMetadata.

Test case:

Xaml:

<Page ... >
    <Grid>
        <Button Name="TestButton" />
        <i:Interaction.Behaviors>
            <!-- Does not work -->
            <c:EventTriggerBehavior SourceObject="{x:Bind TestButton}" EventName="Click" />
            <!-- Does work -->
            <!-- <c:EventTriggerBehavior SourceObject="{Binding ElementName=TestButton}" EventName="Click" /> -->
        </i:Interaction.Behaviors>
    </Grid>
</Page>

The following will then happen in EventTriggerBehavior when the page is being loaded:
1. EventName binding triggering OnEventNameChanged setting the event name
2. OnAttached is triggered and does ReadLocalValue to check against DependencyProperty.UnsetValue, because this is true it sets the resolvedSource to the parent Grid.
3. OnAttached invokes SetResolvedSource which will invoke RegisterEvent because the resolvedSource is not null.
4. RegisterEvent code will throw an exception in because the event cannot be found in the sourceObjectType.

The different between {x:Bind ...} and {Binding ...} is that at 2 that {x:Bind ...} The ReadLocalValue returns in the beginning DependencyProperty.UnsetValue, but with {Binding ...} the value null.

A fix for this issue would be changing the default value of SourceObjectProperty PropertyMetadata with DependencyProperty.UnsetValue.
Or instead of a ReadLocalValue for DependencyProperty.UnsetValue a normal check against null because the target is almost always a binding or code assigned value?

Hello,

I use InvokeCommandAction in order to invoke command from a page. Everything works very well, however, if I enable NavigationCacheMode on a page then I start to have a trouble.

Example
The first page has NavigationCacheMode="Enabled" and contains some InvokeCommandAction. If I navigate to different page, then I go back, the InvokeCommandAction is called twice.

xmlns:i="using:Microsoft.Xaml.Interactivity"
xmlns:iCore="using:Microsoft.Xaml.Interactions.Core"

<GridView ...>
    <i:Interaction.Behaviors>
        <iCore:EventTriggerBehavior EventName="ItemClick">
            <iCore:InvokeCommandAction Command="{Binding MyCommand}" />
        </iCore:EventTriggerBehavior>
    </i:Interaction.Behaviors>
</GridView>

// I use MVVM Light Toolkit
public RelayCommand MyCommand { get; private set; }
MyCommand = new RelayCommand(() => {  ... });

I have a GridView hooked up to an observable collection of type Person ( POCO ).
I want to reroute the tapped event to a command in my viewmodel through use of InvokeCommandAction.
By using this I also use a CommandParameter, this is bound to a SelectedPerson ( of type Person ) property on the viewmodel in TwoWay mode ( general binding no x:Bind ).

If the selectedPerson is NULL and the Observable collection is NULL you'll get an invalid cast exception of the TappedRoutedEventArgs to Person.

I would have thought I would get NULL as input in my method ( that is linked to the command ).

Changing every reference to Person in this chain to object fixes the problem, but that would not be that great I guess.
Also when there are items in the observable collection everything works.

Repo: https://github.com/Depechie/TapCommand
Due to issue #102 I was unable to test this with the samples project to debug myself...