Create DataTemplate in code behind

Question

How do i add controls to datatemplates programmatically?

For Example. Below I\'ve created TextBlock and DataTemplate.

TextBlock text = new TextBlock(         


        

Answer 1

I know it is an work-around, but I published a tip in code project (http://www.codeproject.com/Tips/808808/Create-Data-and-Control-Templates-using-Delegates) that allows you to create a data-template using a delegate. For example:

TemplateGenerator.CreateDataTemplate(() => new TextBox());

This will be enough to create a datatemplate that creates a new textbox. If you want a binding too, it could be written like:

TemplateGenerator.CreateDataTemplate
(
  () =>
  {
    var result = new TextBox();
    result.SetBinding(TextBox.TextProperty, "PathForTheBinding");
    return result;
  }
);

The code of the TemplateGenerator is the following:

/// <summary>
/// Class that helps the creation of control and data templates by using delegates.
/// </summary>
public static class TemplateGenerator
{
  private sealed class _TemplateGeneratorControl:
    ContentControl
  {
    internal static readonly DependencyProperty FactoryProperty = DependencyProperty.Register("Factory", typeof(Func<object>), typeof(_TemplateGeneratorControl), new PropertyMetadata(null, _FactoryChanged));

    private static void _FactoryChanged(DependencyObject instance, DependencyPropertyChangedEventArgs args)
    {
      var control = (_TemplateGeneratorControl)instance;
      var factory = (Func<object>)args.NewValue;
      control.Content = factory();
    }
  }

  /// <summary>
  /// Creates a data-template that uses the given delegate to create new instances.
  /// </summary>
  public static DataTemplate CreateDataTemplate(Func<object> factory)
  {
    if (factory == null)
      throw new ArgumentNullException("factory");

    var frameworkElementFactory = new FrameworkElementFactory(typeof(_TemplateGeneratorControl));
    frameworkElementFactory.SetValue(_TemplateGeneratorControl.FactoryProperty, factory);

    var dataTemplate = new DataTemplate(typeof(DependencyObject));
    dataTemplate.VisualTree = frameworkElementFactory;
    return dataTemplate;
  }

  /// <summary>
  /// Creates a control-template that uses the given delegate to create new instances.
  /// </summary>
  public static ControlTemplate CreateControlTemplate(Type controlType, Func<object> factory)
  {
    if (controlType == null)
      throw new ArgumentNullException("controlType");

    if (factory == null)
      throw new ArgumentNullException("factory");

    var frameworkElementFactory = new FrameworkElementFactory(typeof(_TemplateGeneratorControl));
    frameworkElementFactory.SetValue(_TemplateGeneratorControl.FactoryProperty, factory);

    var controlTemplate = new ControlTemplate(controlType);
    controlTemplate.VisualTree = frameworkElementFactory;
    return controlTemplate;
  }
}

And it has a method for ControlTemplates too.

Answer 2

Although Archedius's method works, officially it is deprecated and instead recommended way to programmatically create a template is to load XAML from a string or a memory stream using the Load method of the XamlReader class like this...

public DataTemplate Create(Type type)
{
    StringReader stringReader = new StringReader(
    @"<DataTemplate 
        xmlns=""http://schemas.microsoft.com/winfx/2006/xaml/presentation""> 
            <" + type.Name + @" Text=""{Binding " + ShowColumn + @"}""/> 
        </DataTemplate>");
    XmlReader xmlReader = XmlReader.Create(stringReader);
    return XamlReader.Load(xmlReader) as DataTemplate;
}

Official line taken from msdn: http://msdn.microsoft.com/en-us/library/system.windows.frameworkelementfactory.aspx

Code example from Fredrik Hedblad's post here: Problems with XamlReader generating DataTemplate

Answer 3

You have first to declare a DataTemplate:

DataTemplate template = new DataTemplate { DataType = typeof(< Type of the object the template refers>) };

Then declare a layout panel like StackPanel in this way

FrameworkElementFactory stackPanelFactory = new FrameworkElementFactory(typeof(StackPanel));
stackPanelFactory.SetValue(StackPanel.OrientationProperty, Orientation.Vertical);

and finally attach the TextBlock piece at it:

FrameworkElementFactory title = new FrameworkElementFactory(typeof(TextBlock));
title.SetBinding(TextBlock.TextProperty, new Binding("< name of your binding >"));
stackPanelFactory.AppendChild(title);

in order to display the StackPanel created in this way you have to attach it to the VisualTree:

template.VisualTree = stackPanelFactory;

Hope it helps! :)