<p>I am using a RichTextBox in WPF, and am trying to set the default paragraph spacing to 0 (so that there is no paragraph spacing).  While I could do this in XAML, I would like to achieve it programmatically if possible.  Any ideas?</p>

Using Line Height
```
```
RichTextBox rtb = new RichTextBox();    
Paragraph p = rtb.Document.Blocks.FirstBlock as Paragraph;    
p.LineHeight = 10;
```
```