Question

I’m new to WPF, and I get error everytime I run my code

DoubleAnimation da = new DoubleAnimation();
TranslateTransform tt = (OPMenuScreen.RenderTransform as TransformGroup).Children[0] as TranslateTransform;

da.By = -250;
tt.BeginAnimation(TranslateTransform.XProperty, da);

Why can’t I get OPMenuScreen to move to a -250 Xproperty for TranslateTransform?

Answer 1

Following on from comments…

I’m not sure that the Children property is null in your example – I think it’s more likely that either your RenderTransform is null or it is not an instance of TransformGroup. Either way, you should just need to make sure that you have the following specified in your XAML:

Note: I have no idea what type OPMenuScreen is, so I’ll use Control for the example

<Control ...>
    <Control.RenderTransform>
        <TransformGroup>
            <TranslateTransform />
        </TransformGroup>
    </Control.RenderTransform>
</Control>