StackPanel

Arranges child elements into a single line horizontal or vertical.

Arranges child elements into a single line that can be either horizontal or vertical

(msdn.microsoft.com/en-us/library/system.windows.controls.stackpanel.aspx)

This control measures in the direction of stacking at Double.PositiveInfinity

<stackpanel Name="StackPanel1" 
    Height=40 
    Width=200 
    Orientation="Vertical" 
    Grid.ColumnSpan="1" 
    Grid.Row="2"/gt 
  
   <Label Content="Single" FontSize="15" /> 
   <Button> Button One</Button> 
</stackpanel> 

Similar to the WrapPanel except it does not wrap the content
Instead it stretches its content in one direction, allowing you to stack them
This control stretches its content by default, although this can be changed by overridding the HorizontalAlignment or VerticalAlignment properties of the child elements