How to get WPF Window to autosize to content and no more
You need to use SizeToContent property, check the msdn link.
Example:
<Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" … SizeToContent="WidthAndHeight">