This article defines the text with underline decoration with dashes, overline decoration with dashes and underlinedecoration in WPF and XAML.
TextDecorations - A text decoration is a visual ornament that you can add to text.
Underline decoration with dashes
Now Drag and drop a TextBlock control on the form.
XAML code
<Window x:Class="MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="525">
<StackPanel>
<TextBlock FontSize="24" Width="180" VerticalAlignment="Center">
Rohatash Kumar
<TextBlock.TextDecorations>
<TextDecoration Location="Underline"
PenThicknessUnit="FontRecommended">
<TextDecoration.Pen>
<Pen Brush="Red" Thickness="1">
<Pen.DashStyle>
<DashStyle Dashes="5"/>
</Pen.DashStyle>
</Pen>
</TextDecoration.Pen>
</TextDecoration>
</TextBlock.TextDecorations>
</TextBlock>
</StackPanel>
</Window>
The form looks like this.

Figure1.gif
Overline decoration with dashes
The below code defines the Overline decoration with dashes in XAML.
XAML code
<StackPanel>
<TextBlock FontSize="24" Width="180" VerticalAlignment="Center">Rohatash Kumar
<TextBlock.TextDecorations>
<TextDecoration Location="OverLine"
PenThicknessUnit="FontRecommended">
<TextDecoration.Pen>
<Pen Thickness="3">
<Pen.Brush>
<LinearGradientBrush
StartPoint="0,0.5" EndPoint="1,0.5">
<LinearGradientBrush.GradientStops>
<GradientStop Color="LimeGreen" Offset="0" />
<GradientStop Color="Yellow" Offset="1" />
</LinearGradientBrush.GradientStops>
</LinearGradientBrush>
</Pen.Brush>
<Pen.DashStyle>
<DashStyle Dashes="0.5, 3, 1, 2" />
</Pen.DashStyle>
</Pen>
</TextDecoration.Pen>
</TextDecoration>
</TextBlock.TextDecorations>
</TextBlock>
</StackPanel>
The form looks like this.

Figure2.gif
underline decoration
The below code defines the underline decoration in XAML.
XAML code
<Window x:Class="MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="525">
<Grid >
<TextBlock TextDecorations=" underline" Height="23" FontWeight="Bold" HorizontalAlignment="Left" Margin="10,10,0,0" Name="TextBlock1" Text="Rohatash Kumar" VerticalAlignment="Top" FontFamily="Verdana" Foreground="Blue" />
</Grid>
</Window>
The window form looks like this.

Figure3.gif