YTPlayer/MainWindow.xaml

<Window x:Class="YTPlayer.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:YTPlayer"
        mc:Ignorable="d"
        Title="MainWindow" Height="350" Width="525">
    <DockPanel>
        
        <WebBrowser Name="wbSample"></WebBrowser>
    </DockPanel>

</Window>