MyMovies/MyMoviesWPF/MVVM/View/LogInControl.xaml

<UserControl x:Class="MyMoviesWPF.MVVM.View.LogInControl"
             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:materialDesign="http://materialdesigninxaml.net/winfx/xaml/themes"      
             xmlns:local="clr-namespace:MyMoviesWPF.MVVM.View"
             mc:Ignorable="d" 
             d:DesignHeight="450" d:DesignWidth="800">
    <Grid>

        <TextBox 
                HorizontalAlignment="Left" Margin="32,54,0,0" VerticalAlignment="Top" Width="368" Height="50"
                Text="{Binding EnteredLogin}" FontFamily="Segoe UI" 
                Style="{DynamicResource MaterialDesignOutlinedTextBox}"  BorderBrush="{DynamicResource MaterialDesignBodyLight}" 
                materialDesign:HintAssist.Hint="Login" BorderThickness="1.5" />


        <PasswordBox 
                Name="Password" 
                HorizontalAlignment="Left" Margin="32,142,0,0" VerticalAlignment="Top" Width="368" Height="50"
                Style="{DynamicResource MaterialDesignOutlinedPasswordBox}"  BorderBrush="{DynamicResource MaterialDesignBodyLight}" 
                materialDesign:HintAssist.Hint="Password" BorderThickness="1.5" />

        <Button 
                    Content="Войти"
                    FontFamily="Segoe UI" FontSize="20" FontStyle="Normal" FontWeight="Normal" Foreground="White"
                    Command="{Binding SignIn}" CommandParameter="{Binding ElementName=Password}" Margin="32,278,400,140" Cursor="Hand" />
    </Grid>
</UserControl>