Question

I have a Silverlight 4 application where I have some states defined in XAML, and use VisualStateManager.GoToState(this, "stateName", false) which works as expected.

The problem however is that some of the state’s properties are bound to the UI so the user can customize things such as the colour. It is possible to do this when in that state (lets say state A). The changes do not reflect until I change to another state, and then back to state A. The problem is not the binding from the UI to the underlying properties (they have the expected values), but rather the state needs to be refreshed – or at least that is my conclusion.

At first I just tried VisualStateManager.GoToState(this, "StateA", false) but found out that “if the control is already in the stateName state, GoToState takes no action returns true”.

I then tried with no success, although it is really not a nice solution:

VisualStateManager.GoToState(this, "StateB", false);
VisualStateManager.GoToState(this, "StateA", false);

Does anyone know how I can force a refresh, or a workaround?

UPDATE:
I managed to get it to work with a combination of the answer below and using the following code when the dependency property changed. The Storyboard.Stop() and Storyboard.Begin() seemed to take into account the new value of the properties set from the UI.

if (VisualStateManager.GoToState(this, "StateA", false))
{
    VisualState stateA = (VisualState)VisualStateGroup.States[0];
    stateA.Storyboard.Stop();
    stateA.Storyboard.Begin();
}

Answer 1

This code should work:

VisualStateManager.GoToState(this, "StateB", false);
VisualStateManager.GoToState(this, "StateA", false);

That is a typical Silverlight/WPF way to force a refresh. While it seems hacky, I’ve seen this exact same approach in Microsoft and Silverlight toolkit code.

Now, my guess is that the control hasn’t loaded yet or you aren’t invoking the state change when the properties change.

You need to do two things:

1. In OnApplyTemplate or the control’s loaded event, put your control into the proper state. DependencyProperties are often updated before the control actually finishes loading the templates. In this scenario, even if you called GoToState, there is no template so it won’t do anything because there is no template.

2. Make sure that in the Property Change handler for the dependency property, you are calling the state changes.

For you reference, you register a PropertyChanged handler like this:

 public static readonly DependencyProperty MinValueProperty =
        DependencyProperty.Register("MinValue", typeof(double), typeof(ScaleValueConverter), new PropertyMetadata(0.0d,OnMinValuePropertyChanged));