Question

I created a Textbox Template as well as states for it. The states are mainly there so that I can use storyboards to display / hide visual elements.

For example, I have an “Error” States Group, which has transitions such as “New Errors” and “No Errors”.

I also have triggers that check if the control’s “Validate.HasError” is set to “True” or “False”.

I would like to change my control’s state by using these triggers, so that I can play the right animation whenever the control fails validation.

In other words, can I change the control’s state to “New Errors” or “No Errors” by using these triggers ?

I would preferably like to change the states without having to use code-behind (i.e.: VisualStateManager.GoToState(…))

Answer 1

Instead of using states, I simply assigned different storyboards when the Trigger’s actions get activated or deactivated:

<ControlTemplate.Triggers>
    <Trigger Property="Validation.HasError" Value="true">
        <Trigger.ExitActions>
            <BeginStoryboard x:Name="HideError_BeginStoryboard" Storyboard="{StaticResource HideError}"/>
        </Trigger.ExitActions>
        <Trigger.EnterActions>
            <BeginStoryboard Storyboard="{StaticResource DisplayError}"/>
        </Trigger.EnterActions>
    </Trigger>
</ControlTemplate.Triggers>