CODEWITHSUNDEEP
c#wpfuser-controlswindows-phone-8.1windows-phone
superpuccio
superpuccio

Reputation: 12972

Accessing an element inside a UserControl resource

I have a xaml file where I defined a UserControl with a storyboard as a resource this way:

<UserControl.Resources>
        <Storyboard x:Key="RotateImage">
            <DoubleAnimation x:Name="RotateImageAnimation" From="0" To="360" RepeatBehavior="Forever"  Duration="00:00:00.5" Storyboard.TargetName="rotateTransform" Storyboard.TargetProperty="Angle"/>
        </Storyboard>            
</UserControl.Resources>

I'd like to access the RotateImageAnimation from the code behind, but if I write something like:

public void Foo(){
    RotateImageAnimation.To = 170;
}

I get a runtime NullPointerException. How can I access the element within the resource? Thank you in advance.

Upvotes: 1

Views: 1817

Answers (2)

123 456 789 0
123 456 789 0

Reputation: 10865

Access your resources using the following code:

public void Foo(){
    var storyBoard = this.Resources["RotateImage"] as Storyboard;
    // Get the storboard's value to get the DoubleAnimation and manipulate it.
    var rotateImageAnimation = (DoubleAnimation)storyBoard.Children.FirstOrDefault();
}

Upvotes: 3

Ahmed Rashad Mohamed
Ahmed Rashad Mohamed

Reputation: 842

Adding on llll's Answer, After you got the storyboard object, you can access the double Animation using storyboard's Children property.

var storyBoard = this.Resources["RotateImage"] as Storyboard;
var rotateImageAnimation = (DoubleAnimation)storyBoard.Children[0];

Please note accessing the animation using children[0] is the easiest as your storyboard is simple.

Upvotes: 1

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