double click on appbar of this window: ``` <Controls:MetroWindow x:Class="WpfApplication9.MainWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:Controls="clr-namespace:MahApps.Metro.Controls;assembly=MahApps.Metro" Title="MainWindow" Height="350" Width="525" FlowDirection="RightToLeft"> <Grid> </Grid> </Controls:MetroWindow> ```