Scool/Views/AddTeacher.axaml

<UserControl xmlns="https://github.com/avaloniaui"
             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"
             mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
             xmlns:vm="using:scool.ViewModels"
			       x:DataType="vm:MainWindowViewModel"
             x:Class="scool.Views.AddTeacher">

  <Grid>
    <StackPanel Orientation="Vertical" HorizontalAlignment="Center" Margin="15">
      <Button Command="{Binding ToData}" HorizontalAlignment="Right" Margin="0,0,0,10">Назад</Button>
      <StackPanel Orientation="Horizontal">
        <TextBox Watermark="Фамилия"  Text="{Binding AddTeacherVM.TSurname}"/>
        <TextBox Margin="10,0,0,0" Watermark="Имя"  Text="{Binding AddTeacherVM.TName}"/>
        <TextBox Margin="10,0,0,0" Watermark="Отчество"  Text="{Binding AddTeacherVM.TPatronymic}"/>
      </StackPanel>
      <DatePicker Margin="0,15,20,0" SelectedDate="{Binding AddTeacherVM.TBirthday}"/>
      <StackPanel Orientation="Horizontal">
        <RadioButton Content="Мужской" Margin="0,0,20,0" IsChecked="{Binding AddTeacherVM.TGenderM}"/>
        <RadioButton Content="Женский" Margin="0,0,0,0"/>
      </StackPanel>
      <StackPanel Orientation="Horizontal">
        <TextBlock Text="Стаж работы" VerticalAlignment="Center" Margin="0,0,20,0"/>
        <TextBox Text="{Binding AddTeacherVM.TExp}"/>
      </StackPanel>
      <TextBox Watermark="email@mail.com" Margin="0,10,10,0" Text="{Binding AddTeacherVM.TMail}"/>
      <TextBox Watermark="880005553535" Margin="0,10,10,0" Text="{Binding AddTeacherVM.TPhone}"/>
      <StackPanel Orientation="Horizontal">
        <ComboBox Margin="0,10,10,0" Width="400" ItemsSource="{Binding AddTeacherVM.CollSub}" SelectedItem="{Binding AddTeacherVM.SelectSubject}" MaxDropDownHeight="250">
          <ComboBox.ItemTemplate>
            <DataTemplate>
              <TextBlock Text="{Binding Subject1}"/>
            </DataTemplate>
          </ComboBox.ItemTemplate>
        </ComboBox>
        <ListBox ItemsSource="{Binding AddTeacherVM.CollSubSelect}" Width="300" Height="150" Margin="30,10,0,0">
          <ListBox.ItemTemplate>
            <DataTemplate>
              <TextBlock Text="{Binding Subject1}"/>
            </DataTemplate>
          </ListBox.ItemTemplate>
        </ListBox>
      </StackPanel>
      <StackPanel Orientation="Horizontal" HorizontalAlignment="Center">
        <Button Margin="0,10,0,0" Command="{Binding AddTeacherVM.AddNew}" Content="Добавить"/>
      </StackPanel>
    </StackPanel>
  </Grid>
  
</UserControl>