How would I databind a Paragraph to a TextBlock?

Question

How would I take a Paragraph object and databind them to the TextBlock for use in a DataTemplate? A plain bind does nothing, just a ToString() of the Paragraph object.

The InLines property would let me add a list of TextRun's that make up the Paragraph manually, but that can't be bound to and I could really do with a binding based solution.

Edited question to focus on what I really need to do.

Answer 1

You could try to create your own DataTemplate for Paragraph objects that wraps each one in its own FlowDocument, which is then presented via a RichTextBox (readonly, of course)

Answer 2

I'm not sure if you can bind a Paragraph directly to a TextBlock's inlines. However, I was able to find the class BindableRun that lets you bind to the Run's Text property. Would that work for you instead?

EDIT: Modified my answer to reflect the edited question.

Answer 3

Here's an example using a nested ItemsControl. Unfortunately, it will make one TextBlock per Inline instead of putting the whole Paragraph into one TextBlock:

<Grid xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:sys="clr-namespace:System;assembly=mscorlib"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"&gt;
    <Grid.Resources>
        <FlowDocument x:Key="document">
            <Paragraph><Run xml:space="preserve">This is the first paragraph.  </Run><Run>The quick brown fox jumps over the lazy dog.</Run></Paragraph>
            <Paragraph><Run xml:space="preserve">This is the second paragraph.  </Run><Run>Two driven jocks help fax my big quiz.</Run></Paragraph>
            <Paragraph><Run xml:space="preserve">This is the third paragraph.  </Run><Run>Sphinx of black quartz, judge my vow!</Run></Paragraph>
        </FlowDocument>
        <DataTemplate DataType="{x:Type Paragraph}">
            <ItemsControl ItemsSource="{Binding Inlines}" IsHitTestVisible="False">
                <ItemsControl.ItemsPanel>
                    <ItemsPanelTemplate>
                        <WrapPanel/>
                    </ItemsPanelTemplate>
                </ItemsControl.ItemsPanel>
            </ItemsControl>
        </DataTemplate>
    </Grid.Resources>
    <ListBox ItemsSource="{Binding Blocks, Source={StaticResource document}}"/>
</Grid>

If you want one Paragraph per element you should probably do as suggested and use a read-only RichTextBox, or do what this person did and derive from TextBlock so that the Inlines property can be bound.

Answer 4

I had a similar need and solved it along the lines of Andy's answer... I created a BindableTextBlock:

class BindableTextBlock : TextBlock
{
    public Inline BoundInline
    {
        get { return (Inline)GetValue(BoundInlineProperty); }
        set { SetValue(BoundInlineProperty, value); }
    }

    public static readonly DependencyProperty BoundInlineProperty =
        DependencyProperty.Register("BoundInline", typeof(Inline), typeof(BindableTextBlock),
            new UIPropertyMetadata((PropertyChangedCallback)((d, e) => { ((BindableTextBlock)d).Inlines.Clear(); ((BindableTextBlock)d).Inlines.Add(e.NewValue as Inline); })));
}

Then in my XAML I can bind to the BoundInline dependency property:

    <DataTemplate x:Key="TempTemplate">
        <t:BindableTextBlock TextWrapping="Wrap" BoundInline="{Binding Path=TextInlines}" Grid.Column="1" Grid.Row="1" Grid.ColumnSpan="2" />
    </DataTemplate>

The one drawback to this is that you can only bind a single root Inline to the textblock, which worked fine for my situation as my content is all wrapped in a top-level Span.