SharpCalculator/SharpCalculator.Avalonia/MainWindow.axaml

<Window
    xmlns="https://github.com/avaloniaui"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:ag="clr-namespace:AvaloniaAutoGrid;assembly=AvaloniaAutoGrid"
    x:Class="SharpCalculator.Avalonia.MainWindow"
    Title="SharpCalculator"
    Icon="avares://SharpCalculator.Avalonia/assets/icon.ico"
    FontFamily="Consolas" FontSize="24"
    MinWidth="460" MinHeight="570"
    Width="460" Height="570">

    <!-- ReSharper disable Xaml.MissingGridIndex -->
    <ag:AutoGrid Margin="10" 
                 ColumnDefinitions="*"
                 RowDefinitions="1* 40 1* 330">
        <TextBox Name="Input"
                 TextChanged="Input_OnTextChanged"
                 BorderThickness="2"
                 BorderBrush="#AAAAAA"
                 TextWrapping="Wrap"
                 ScrollViewer.HorizontalScrollBarVisibility="Disabled"
                 ScrollViewer.VerticalScrollBarVisibility="Auto"/>
        
        <StackPanel Orientation="Horizontal">
            <TextBlock VerticalAlignment="Center"
                       Foreground="#AAAAAA"
                       Text="="/>
            <TextBox Name="Output" 
                     Margin="16 0 0 0" 
                     VerticalAlignment="Center"
                     VerticalContentAlignment="Center"
                     IsReadOnly="True"
                     BorderThickness="0"
                     TextWrapping="NoWrap"
                     ScrollViewer.HorizontalScrollBarVisibility="Auto"
                     ScrollViewer.VerticalScrollBarVisibility="Disabled"/>
        </StackPanel>
        
        <TextBox Name="History"
                 Foreground="Gray"
                 BorderThickness="1"
                 BorderBrush="Gray"
                 IsReadOnly="True"
                 TextWrapping="NoWrap"
                 FontSize="18"
                 ScrollViewer.HorizontalScrollBarVisibility="Auto"
                 ScrollViewer.VerticalScrollBarVisibility="Auto"/>
        
        <!-- ReSharper disable once Xaml.MissingGridIndex -->
        <ag:AutoGrid 
                ColumnDefinitions="*"
                RowDefinitions="*"
                ColumnCount="7" RowCount="5"
                VerticalAlignment="Bottom"
                MinWidth="440" MaxWidth="440" 
                MinHeight="320" MaxHeight="320">
            
            <!--  1st row  -->
            
            <Button Classes="button gray"
                Click="ClearButton_OnClick" Content="AC"/>

            <Button Classes="button gray"
                Click="MathButton_OnClick" Content="("/>
            
            <Button Classes="button gray"
                Click="MathButton_OnClick" Content=")" />
            
            <Button Classes="button orange"
                Click="MathButton_OnClick" Content="/"/>

            <Button Classes="button gray"
                Click="MathButton_OnClick" Content="1/x"/>

            <Button Classes="button gray"
                Click="MathButton_OnClick" Content="sin"/>

            <Button Classes="button gray"
                Click="MathButton_OnClick" Content="asin"/>

            <!--  2nd row  -->

            <Button Classes="button"
                Click="MathButton_OnClick" Content="7"/>

            <Button Classes="button"
                Click="MathButton_OnClick" Content="8"/>
            
            <Button Classes="button"
                Click="MathButton_OnClick" Content="9"/>
            
            <Button Classes="button orange"
                Click="MathButton_OnClick" Content="*"/>

            <Button Classes="button gray"
                Click="MathButton_OnClick" Content="^"/>

            <Button Classes="button gray"
                Click="MathButton_OnClick" Content="cos"/>

            <Button Classes="button gray"
                Click="MathButton_OnClick" Content="acos"/>

            <!--  3th row  -->

            <Button Classes="button"
                Click="MathButton_OnClick" Content="4"/>

            <Button Classes="button"
                Click="MathButton_OnClick" Content="5"/>

            <Button Classes="button"
                Click="MathButton_OnClick" Content="6"/>

            <Button Classes="button orange"
                Click="MathButton_OnClick" Content="-"/>

            <Button Classes="button gray"
                FontSize="22"
                Click="MathButton_OnClick" Content="10^x"/>

            <Button Classes="button gray"
                Click="MathButton_OnClick" Content="tg"/>

            <Button Classes="button gray"
                Click="MathButton_OnClick" Content="atg"/>

            <!--  4th row  -->

            <Button Classes="button"
                Click="MathButton_OnClick" Content="1"/>

            <Button Classes="button"
                Click="MathButton_OnClick" Content="2"/>

            <Button Classes="button"
                Click="MathButton_OnClick" Content="3"/>

            <Button Classes="button orange"
                Click="MathButton_OnClick" Content="+"/>

            <Button Classes="button gray"
                Click="MathButton_OnClick" Content="e"/>

            <Button Classes="button gray"
                Click="MathButton_OnClick" Content="ctg"/>

            <Button Classes="button gray"
                Click="MathButton_OnClick" Content="actg"/>

            <!--  5th row  -->

            <Button Classes="button"
                Click="MathButton_OnClick" Content="0"/>

            <Button Classes="button"
                Click="MathButton_OnClick" Content="."/>

            <Button Classes="button"
                Click="MathButton_OnClick" Content="%"/>

            <Button Classes="button orange"
                Click="ResultButton_OnClick" Content="="/>

            <Button Classes="button gray"
                Click="MathButton_OnClick" Content="π"/>

            <Button Classes="button gray"
                FontSize="22"
                Click="MathButton_OnClick" Content="rand"/>

            <Button Classes="button gray" 
                Click="MathButton_OnClick" Content="ln"/>
            </ag:AutoGrid>
    </ag:AutoGrid>
</Window>