C# WPF: How to get UserControl from MainWindow?

       DataContext="MainViewModel" x:Class="Skizzen_Editor.MainWindow"
      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"
      xmlns:local="clr-namespace:Skizzen_Editor"
      mc:Ignorable="d"
      Name="Win_SkizzenEditor" Background="Transparent"
 

 

 

here I've just changed in

but something is going wrong. It seems It doenst work.

Can you please suggest me a solution?

Or is it better to make a new UserControl and out the existing MainWindow.xaml inside of it? 

 

Thanks in advance