MyMovies/MyMoviesWPF/MVVM/View/UserView.xaml

<UserControl x:Class="MyMoviesWPF.MVVM.View.UserView"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             xmlns:local="clr-namespace:MyMoviesWPF.MVVM.View"
             xmlns:viewmodel="clr-namespace:MyMoviesWPF.MVVM.ViewModel" 
             mc:Ignorable="d" 
             d:DesignHeight="450" d:DesignWidth="800">

    <Grid>
        <StackPanel Grid.Column="2" Margin="0,10,0,10" Orientation="Vertical" HorizontalAlignment="Center" Width="350">
            <StackPanel Height="35" Orientation="Horizontal">
                <Button Width="175" Content="Регистрация" Command="{Binding OpenMainSR}" CommandParameter="SignUp"/>
                <Button Width="175" Content="Вход"        Command="{Binding OpenMainSR}" CommandParameter="LogIn"/>
            </StackPanel>
            <StackPanel Height="35" Orientation="Horizontal" HorizontalAlignment="Center" VerticalAlignment="Bottom">
                <Button Style="{DynamicResource MaterialDesignRaisedSecondaryDarkButton}" Width="175" Content="Корзина" Cursor="Hand" />
            </StackPanel>
        </StackPanel>            
    </Grid>
</UserControl>