从视图模型（WPF）在视图中调用动画

Question

What I have: A style resource which contains animation definitions and a view definition, a viewmodel which contains Data, Properties and ICommands.

Currently the application can call VM functions via Button Clicks (using ICommand), View with binding to VM Properties & it is able to run animations from a button.click event trigger.

What I am looking to do; If a style is applied to a listbox(for example) How do I trigger animations from the VM directly? IE if some property on the data changes, is it possible to cause an animation to run? I know I could do this with a UserControl, but I'm trying to seperate my program into more clearly defined Views and Viewmodels. I don't want Code in my View, and I don't want animations in my VM.

Answer 1

You almost answered your own question there when you said that it is able to run animations from a button.click event trigger . The actual answer is yes, you can start an animation using a DataTrigger that is data bound to a view model property, or an EventTrigger using a custom RoutedEvent in the same way:

<Style>
    <Style.Triggers>
        <DataTrigger Binding="{Binding IsAnimationRunning}" Value="True">
            <DataTrigger.EnterActions>
                <BeginStoryboard>
                    <Storyboard>
                        <SomeAnimation />
                    </Storyboard>
                </BeginStoryboard>
            </DataTrigger.EnterActions>
        </DataTrigger>
    </Style.Triggers>
</Style>

This would start the animation whenever the IsAnimationRunning property is changed from false to true .

Answer 2

EDIT: On further research, I think what you need is: WPF Command with Click Event Handler

The idea is that you should call the ICommand within the event, allowing further event subscriptions. It still feels messy, since it pretty much ignores the standard command binding syntax, but it amounts to the same thing, since the command binding is still in the view.