CODEWITHSUNDEEP
c#.netwpfxamlexpression-blend
jeremy303
jeremy303

Reputation: 9241

Design time data for both ViewModel and DependencyProperties?

I've been using the d:DataContext property to provide design-time representations of my view models to my views, but I've now encountered a situation where my view has also has XAML bindings to a number of a number DependencyPropertymembers I've declared in the view control that I'd also like to populate with design time data.

How can I provide design time data for both my ViewModel (via sample data) and the control's dependency properties?

Obviously I can just roll all of the properties into my ViewModel to avoid the problem, but I'd rather not, if possible.

Upvotes: 0

Views: 328

Answers (2)

jeremy303
jeremy303

Reputation: 9241

A workable solution for my case was to use d:DataContext to provide design-time data representing my view model and use the Binding FallbackValue property to provide the design-time data for my View UserControl's dependency properties.

If no DataContext is provided, these fallback values will leak into run-time, but for a MVVM view this shouldn't really be an issue.

<UserControl
         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
         x:Name="myView" 
         x:Class="Example.MyView" 
         mc:Ignorable="d"                        
         d:DataContext="{d:DesignData /SampleData/MyViewModelSampleData.xaml}">

        <Label Content="{Binding ElementName=myView, Path=ADependencyPropertyOnMyView}"/>

</UserControl>

Upvotes: 0

Peter Ritchie
Peter Ritchie

Reputation: 35870

It would be hard to tell you how to do anything specific with the source of those dependency properties without knowing what the source of the dependency properties is. ViewModel is easy: just load it with data at design time. Technically, the answer is to simply populate those properties with values at design time.

Upvotes: 1

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