I am using a ViewModelViewHost in my ReactiveUI WPF application to display a view for an arbitrary viewmodel. When changing the viewmodel, the control fades in/out the view as a transition. I would like to disable this animation. I have found a Transition property but it seems this can only be used to change the transition, not disable it.
Is there any way to do this?
You could modify the default template for the TransitioningContentControl by for example setting the Duration properties of all animations to 0:
<rx:RoutedViewHost
Router="{Binding Router, Mode=OneTime}"
HorizontalContentAlignment="Stretch"
VerticalContentAlignment="Stretch">
<rx:RoutedViewHost.Style>
<Style TargetType="rx:TransitioningContentControl">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="rx:TransitioningContentControl">
<Grid
x:Name="PART_Container"
VerticalAlignment="{TemplateBinding VerticalAlignment}"
HorizontalAlignment="{TemplateBinding HorizontalAlignment}">
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="PresentationStates">
<VisualState x:Name="Normal">
<Storyboard>
<ObjectAnimationUsingKeyFrames
BeginTime="00:00:00"
Storyboard.TargetName="PART_PreviousContentPresentationSite"
Storyboard.TargetProperty="(UIElement.Visibility)">
<DiscreteObjectKeyFrame KeyTime="00:00:00">
<DiscreteObjectKeyFrame.Value>
<Visibility>Collapsed</Visibility>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="FadeTransition_OutIn">
<Storyboard>
<DoubleAnimation
BeginTime="00:00:00" Duration="00:00:00"
Storyboard.TargetName="PART_PreviousContentPresentationSite"
Storyboard.TargetProperty="(UIElement.Opacity)"
From="1" To="0"/>
<DoubleAnimation
BeginTime="00:00:00" Duration="00:00:00"
Storyboard.TargetName="PART_CurrentContentPresentationSite"
Storyboard.TargetProperty="(UIElement.Opacity)"
From="0" To="1"/>
</Storyboard>
</VisualState>
<VisualState x:Name="FadeDownTransition_OutIn">
<Storyboard>
<DoubleAnimation
BeginTime="00:00:00" Duration="00:00:00"
Storyboard.TargetName="PART_CurrentContentPresentationSite"
Storyboard.TargetProperty="(UIElement.RenderTransform).(TransformGroup.Children)[1].(TranslateTransform.Y)"
From="-30" To="0"/>
<DoubleAnimation
BeginTime="00:00:00" Duration="00:00:00"
Storyboard.TargetName="PART_PreviousContentPresentationSite"
Storyboard.TargetProperty="(UIElement.RenderTransform).(TransformGroup.Children)[1].(TranslateTransform.Y)"
From="0" To="30"/>
<DoubleAnimation
BeginTime="00:00:00" Duration="00:00:00"
Storyboard.TargetName="PART_CurrentContentPresentationSite"
Storyboard.TargetProperty="(UIElement.Opacity)"
From="0" To="1"/>
<DoubleAnimation
BeginTime="00:00:00" Duration="00:00:00"
Storyboard.TargetName="PART_PreviousContentPresentationSite"
Storyboard.TargetProperty="(UIElement.Opacity)"
From="1" To="0"/>
</Storyboard>
</VisualState>
<!-- SlideLeftTransition -->
<VisualState x:Name="SlideLeftTransition_In">
<Storyboard>
<DoubleAnimationUsingKeyFrames
Storyboard.TargetName="PART_CurrentContentPresentationSite"
Storyboard.TargetProperty="(UIElement.RenderTransform).(TransformGroup.Children)[1].(TranslateTransform.X)">
<EasingDoubleKeyFrame KeyTime="00:00:00" Value="-90"/>
<EasingDoubleKeyFrame KeyTime="00:00:00" Value="-90"/>
<EasingDoubleKeyFrame KeyTime="00:00:00" Value="0">
<EasingDoubleKeyFrame.EasingFunction>
<CircleEase EasingMode="EaseOut"/>
</EasingDoubleKeyFrame.EasingFunction>
</EasingDoubleKeyFrame>
</DoubleAnimationUsingKeyFrames>
<DoubleAnimationUsingKeyFrames
Storyboard.TargetName="PART_CurrentContentPresentationSite"
Storyboard.TargetProperty="(UIElement.Opacity)">
<DiscreteDoubleKeyFrame KeyTime="00:00:00" Value="0"/>
<DiscreteDoubleKeyFrame KeyTime="00:00:00" Value="1"/>
</DoubleAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames
Storyboard.TargetName="PART_PreviousContentPresentationSite"
Storyboard.TargetProperty="(UIElement.Visibility)">
<DiscreteObjectKeyFrame KeyTime="00:00:00">
<DiscreteObjectKeyFrame.Value>
<Visibility>Collapsed</Visibility>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="SlideLeftTransition_Out">
<Storyboard>
<DoubleAnimation
BeginTime="00:00:00" Duration="00:00:00"
Storyboard.TargetName="PART_PreviousContentPresentationSite"
Storyboard.TargetProperty="(UIElement.RenderTransform).(TransformGroup.Children)[1].(TranslateTransform.X)"
From="0" To="-90"/>
<ObjectAnimationUsingKeyFrames
Storyboard.TargetName="PART_CurrentContentPresentationSite"
Storyboard.TargetProperty="(UIElement.Visibility)">
<DiscreteObjectKeyFrame KeyTime="00:00:00">
<DiscreteObjectKeyFrame.Value>
<Visibility>Collapsed</Visibility>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<ContentPresenter
x:Name="PART_PreviousContentPresentationSite"
Content="{x:Null}"
ContentTemplate="{TemplateBinding ContentTemplate}"
HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
VerticalAlignment="{TemplateBinding VerticalContentAlignment}">
<ContentPresenter.RenderTransform>
<TransformGroup>
<TransformGroup.Children>
<ScaleTransform ScaleX="1" ScaleY="1" />
<TranslateTransform X="0" Y="0" />
</TransformGroup.Children>
</TransformGroup>
</ContentPresenter.RenderTransform>
</ContentPresenter>
<ContentPresenter
x:Name="PART_CurrentContentPresentationSite"
Content="{x:Null}"
ContentTemplate="{TemplateBinding ContentTemplate}"
HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
VerticalAlignment="{TemplateBinding VerticalContentAlignment}">
<ContentPresenter.RenderTransform>
<TransformGroup>
<TransformGroup.Children>
<ScaleTransform ScaleX="1" ScaleY="1" />
<TranslateTransform X="0" Y="0" />
</TransformGroup.Children>
</TransformGroup>
</ContentPresenter.RenderTransform>
</ContentPresenter>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</rx:RoutedViewHost.Style>
</rx:RoutedViewHost>
Simplifying @mm8's answer, the TransitioningContentControl base class has a Duration property that can be set to zero.
<rx:ViewModelViewHost Duration="0">
...
