TextBlock Class

Rather than presenting a single string, a TextBlock can also present a series of strings contained in different Run elements, where each element can have different character-level font attributes. The LineBreak object represents an explicit new line in a TextBlock, and is generally used between surrounding Run elements. LineBreak and Run share a base class (Inline), which makes it possible for a TextBlock to hold a strongly typed InlineCollection of its text model content. That InlineCollection is also the TextBlock XAML content property, and the end result is that to specify items in the TextBlock model you simply specify various Run and LineBreak elements as child elements of the TextBlock.

The following XAML example shows how to define several differently formatted text strings in a TextBlock by using Run objects, separated with LineBreak.

<!-- Display formatted text as Run objects within a TextBlock. -->
<Canvas>
<TextBlock
  FontFamily="Arial" Width="400" Text="Sample text formatting runs">
  <LineBreak/>
  <Run Foreground="Maroon" FontFamily="Courier New" FontSize="24">Courier New 24</Run>
  <LineBreak/>
  <Run Foreground="Teal" FontFamily="Times New Roman" FontSize="18" FontStyle="Italic">Times New Roman Italic 18</Run>
  <LineBreak/>
  <Run Foreground="SteelBlue" FontFamily="Verdana" FontSize="14" FontWeight="Bold">Verdana Bold 14</Run>
</TextBlock>
</Canvas>

The following illustration shows the rendered formatted text from the previous XAML content example.

TextBlock rendering multiple Run objects

LineBreak forces the text in each Run to display on a separate line. Without the LineBreak, the text in each Run would flow together as one line and would often be clipped due to exceeding the TextBlock object width or the width of the Silverlight content area. The following illustration shows how the formatted text would render without using LineBreak objects.

There are really two properties involved in the TextBlock text model: Text, and Inlines. Changing the value of Text is not always advisable, because it can flatten any existing font element formatting on the individual Run items as well as strip the LineBreak elements for a TextBlock that was originally constructed with inlines and not just Text. For details, see Inlines.