15/Pages/AuthPage.xaml

<Page x:Class="Praktika13_Chistyakov.Pages.AuthPage"
      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:Praktika13_Chistyakov.Pages"
      mc:Ignorable="d" 
      d:DesignHeight="450" d:DesignWidth="800"
      Title="Авторизация">

    <Grid Background="White">
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*"/>
            <ColumnDefinition Width="50"/>
            <ColumnDefinition Width="170"/>
            <ColumnDefinition Width="*"/>
        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
            <RowDefinition Height="*"/>
            <RowDefinition Height="105"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>
        <Label Content="Логин" HorizontalAlignment="Right" VerticalAlignment="Top" Height="73" Width="136" RenderTransformOrigin="3.73,0.337" Grid.ColumnSpan="2"/>
        <TextBox x:Name="TextBoxLogin" Grid.Column="2" HorizontalAlignment="Left" Height="73" TextWrapping="Wrap" Text="TextBox" VerticalAlignment="Top" Width="361" Grid.ColumnSpan="2"/>
        <Label Content="Пароль" HorizontalAlignment="Left" Margin="204,78,0,0" VerticalAlignment="Top" Height="73" Width="136" Grid.ColumnSpan="2"/>
        <PasswordBox x:Name="PasswordBox" Grid.Column="2" HorizontalAlignment="Left" Margin="0,78,0,0" VerticalAlignment="Top" Grid.ColumnSpan="2" Width="361" Height="73"/>
        <Button Click="ButtonEnter_OnClick"  Content="Вход" Grid.Column="2" HorizontalAlignment="Left" Margin="0,10,0,0" Grid.Row="1" VerticalAlignment="Top" Width="361" Grid.ColumnSpan="2" Height="27"/>
        <Button Content="Регистрация" Grid.Column="2" HorizontalAlignment="Left" Margin="0,55,0,0" Grid.Row="1" VerticalAlignment="Top" Width="361" Grid.ColumnSpan="2" Height="27"/>

    </Grid>
</Page>