No Target Was Specified For System.Windows.Media.Animation.DoubleAnimation
I am using Syncfusion WPF components 28.1.41 in a my WPF .Net application. I am using the SfStepProgressBar and most of the time it behaves perfectly. However sometimes I seem to get an unhandled exception "No target specified for DoubleAnimation", and the stack trace always seems to show this is due to a call from the SfStepProgressBar. It is inconsistant as the same "inputs" mostly work, but sometimes don't. It's not that my code has failed to specify any "target", because my definitions would be the same each time.
My latest exception shows that it was this line in Storyboard.cs which raised the exception
And here is the stack trace
Here are the definitions of my storyboards used for the animation
<!-- Define the storyboard for Image zoom animation -->
<Storyboard x:Key="ZoomImageStoryboard">
<!-- Animate the ScaleX and ScaleY properties to zoom the image -->
<DoubleAnimation
Storyboard.TargetName="ImageTransform"
Storyboard.TargetProperty="ScaleX"
From="1.0" To="1.1" Duration="0:0:0.2" AutoReverse="True" RepeatBehavior="3x"/>
<DoubleAnimation
Storyboard.TargetName="ImageTransform"
Storyboard.TargetProperty="ScaleY"
From="1.0" To="1.1" Duration="0:0:0.2" AutoReverse="True" RepeatBehavior="3x"/>
</Storyboard>
<!-- Define the storyboard for Text zoom animation -->
<Storyboard x:Key="ZoomTextStoryboard">
<!-- Animate ScaleX (horizontal scaling) -->
<DoubleAnimation Storyboard.TargetName="TextTransform"
Storyboard.TargetProperty="ScaleX"
From="1.0" To="2.0" Duration="0:0:0.3" AutoReverse="True"/>
<!-- Animate ScaleY (vertical scaling) -->
<DoubleAnimation Storyboard.TargetName="TextTransform"
Storyboard.TargetProperty="ScaleY"
From="1.0" To="2.0" Duration="0:0:0.3" AutoReverse="True"/>
</Storyboard>
And here is a single DataTemplate used for one of the stamp states, which includes the triggering of the animation
<!--- Player has this stamp, and there is an unclaimed reward -->
<DataTemplate x:Key="RewardUnclaimedStamp">
<Grid Background="Transparent">
<Grid.RowDefinitions>
<RowDefinition/>
<RowDefinition/>
</Grid.RowDefinitions>
<!-- Show "Unclaimed" but give it some animation to attract the eye -->
<TextBlock Grid.Row="0" Text="Unclaimed!" FontSize="27" Foreground="LimeGreen" FontWeight="Bold" HorizontalAlignment="Center">
<TextBlock.RenderTransform>
<ScaleTransform x:Name="TextTransform"/>
</TextBlock.RenderTransform>
<TextBlock.RenderTransformOrigin>
<!-- Center of the TextBlock -->
<Point X="0.5" Y="0.5"/>
</TextBlock.RenderTransformOrigin>
<TextBlock.Triggers>
<EventTrigger RoutedEvent="TextBlock.Loaded">
<BeginStoryboard Storyboard="{StaticResource ZoomTextStoryboard}"/>
</EventTrigger>
</TextBlock.Triggers>
</TextBlock>
<TextBlock Grid.Row="1" Text="{Binding RewardTitle}"
Width="140" TextWrapping="Wrap"
FontSize="27" TextAlignment="Center" />
</Grid>
</DataTemplate>
If I was principally just doing things wrong, I would expect it not to work, or give me these exceptions all the time. But it works 99% of the time.
Is there anything you can spot, which you would advise me I am not applying correctly?
Thanks, Paul
Hi,
I spent quite some time producing a sample project that demonstrates the issue. I have tried to make this as brief as I could, but it needs to replicate the usage of my real application, This not the same codebase, but I am applying the same principles. Whilst I am not asking you to help debug my application, I will take on suggestions if you think I have not taken the correct approach. But I am sure you will agree that even if I am not doing this the best way, I should not be able to cause the SfStepProgressBar to indirectly raise this DoubleAnimation exception?
I think it important you understand how my real world application is attempting to use the progress bar:
- Another company provides membership based functionality, including a digital version of paper Stampcards (where the holder is given a new stamp on each visit, which may make them eligible for a reward)
- A member may have multiple stampcards associated with their account, and each stampcard may have a different number of stamps, with different rewards available at different stamp levels.
- Our application presents a UI of these stampcards using the SfStepProgressBar to represent any single stampcard at a time
- The user may use "Next" and "Prev" buttons to cycle between their stampcards, with loop-around.
- It uses MVVM so most of the code is in MainWindow_ViewModel.cs
- I have hardcoded the source of data (that would normally be download from the member's account, in a list
_StampcardsList in the VM constructor. A timer is used to simulate selecting the first stampcard, 2 seconds after launch
The property StampcardIndex dictates which stampcard of those available should be current, and represented via the progress bar's layout
Disable animation
Load the StampStepsCollection (ItemSource for progress bar) via LoadStampcardAtIndex()
Restore animation
Select the appropriate SelectedStampIndex (SelectedIndex for progressbar)
- In the VM ensure the USE_TIMER_FOR_DELAYED_MARKER conditional variable is commented out
- Run the application
- Press "Next"
- Note we get the exception
Demonstration #2
In this demo, it is representative of a workaround I saw necessary to add to my end application. In this I use a timer to separate the loading of the collection driving the progress bar, and setting of the SelectedIndex to show the active markers (which actually are not currently looking correct in this sample, but I didn't want to get distracted with that)
- In the VM ensure the USE_TIMER_FOR_DELAYED_MARKER conditional variable is NOT commented out
- Rebuild and run the application
- Use "Next" and "Prev" buttons to cycle between scratchcards
- Note this workaround does seem to have helped, including showing the marker animation. But.....
- Click and keep clicking "Next" as quick as you can. Sooner or later you will get the DoubleAnimation crash again
Attachment: WPF_Customer__Sample_830ac8d5.zip
Regards,
Yathavakrishnan M
Hi,
Thanks for your prompt response. With regard to Demonstration #1, this is exactly the problem I expected.
If you when you had that call stack you had pressed the "Show External Code" button, you would see that whilst my code has modified a property, and raised OnPropertyChanged (that the SfStepProgressBar has it's SelectedIndex property bound to), the callstack shows the progress bar has attempted to start an animation when it was disabled 
regards
Paul
