CODEWITHSUNDEEP
c#xamlresourceswindows-8.1datatemplate
jr.
jr.

Reputation: 1847

How do I create a new instance of a Xaml DataTemplate that has been defined as a resource?

I need to dynamically generate a DataTemplate that is defined as a resource. A seemingly simple task that I found answered nowhere, simply or otherwise. Examples of dynamically generating a DataTemplate ** yes ** but not generating instances of an existing template.

Example of a derived UserControl that contains a DataTemplate by the name of "template" that I want to create a new instance of.

<utilities:UserControlBase x:Class="Photomete.ImageView"
 xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
 xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
 xmlns:local="using:Photomete"
 xmlns:utilities="using:Utilities"
 xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
 xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
 xmlns:viewModels="using:Photomete"
 xmlns:cm="using:Caliburn.Micro"
 xmlns:ia="clr-namespace:Microsoft.Xaml.Interactions.Core;assembly=Microsoft.Xaml.Interactions.dll"
 mc:Ignorable="d"
 FontSize="6"
 d:DesignHeight="300"
 d:DesignWidth="400">

<utilities:UserControlBase.Resources>
    <DataTemplate x:Name="template">
        <ScrollViewer x:Name="imageScroller"
            VerticalScrollBarVisibility="Visible"
            RenderTransformOrigin="0.5,0.5"
            HorizontalScrollBarVisibility="Visible">
            <Image x:Name="image"
                Source="{Binding Source}" />
        </ScrollViewer>
    </DataTemplate>
</utilities:UserControlBase.Resources>

<Viewbox x:Name="viewBox">
    <!-- Content is set in code behind -->
</Viewbox>

My answer follows.

Upvotes: 1

Views: 276

Answers (1)

jr.
jr.

Reputation: 1847

Surprisingly the answer came by fully reading the DateTemplate class documentation! Cast the resource as a DataTemplate and call LoadContent() on it!

object template;
if( !imageView.Resources.TryGetValue( "template", out template ) ) {
  var root = ((DataTemplate) template).LoadContent() as ScrollViewer;
  imageView.ViewBox.Child = root;
}

or as an extension method:

public static T GenerateDataTemplateInstance<T>( this FrameworkElement element, string name ) where T : class
{
  // ******
  object template;
  if( ! element.Resources.TryGetValue( name, out template ) ) {
    return null;
  }

  // ******
  return ((DataTemplate) template).LoadContent() as T;
}

calling the method:

var scrollViewer = userControl.GenerateDataTemplateInstance<ScrollViewer>( "template" );

Upvotes: 1

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