asdfwa/MedicallCenter/MainWindow.xaml

<Window x:Class="MedicallCenter.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:MedicallCenter"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800" Loaded="Window_Loaded" Closing="Window_Closing"
        >
    <Grid>
        <Frame NavigationUIVisibility="Hidden" x:Name="MainFrame"/>
    </Grid>
</Window>