lab4/LR4/MainWindow.xaml

<Window x:Class="LR4.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:LR4"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800">
    <Grid Background="AliceBlue">
        <StackPanel>
            <StackPanel Orientation="Horizontal" HorizontalAlignment="Center" Margin="0,50,0,0">
                <GroupBox Header="Число А" Width="145" Margin="5">
                    <TextBox Foreground="#808080" Background="Beige" Name="x1"  >1</TextBox>
                </GroupBox>
                <GroupBox Header="Число Б" Width="145" Margin="5">
                    <TextBox Foreground="#808080" Background="Beige" Name="x2"  >1</TextBox>
                </GroupBox>
            </StackPanel>
            <StackPanel>
                <GroupBox Header="Выберите нужную функцию" Width="300" >
                    <ComboBox Foreground="#808080" SelectionChanged="Fun_SelectionChanged" Name="Fun" Height="20"></ComboBox>
                </GroupBox>
                <Border Margin="5" BorderThickness="1" CornerRadius="3" BorderBrush="#bababa" Background="Beige" Width="299" Height="20">
                    <Button Background="#0000" BorderBrush="#0000" Foreground="#808080" Content="Вычислить" Click="Result" ></Button>
                </Border>
                <GroupBox Header="Результат" Width="300">
                    <TextBlock Foreground="#808080" Background="Beige" Name="result"></TextBlock>
                </GroupBox>
            </StackPanel>
        </StackPanel>
        
    </Grid>
</Window>