.NET 8でSPREAD for WPFを使う方法を解説！

using System.Collections.ObjectModel;
using System.ComponentModel;
using System.ComponentModel.DataAnnotations;

namespace SpreadGrid_net8
{
    public class Sale : INotifyPropertyChanged
    {
        string? code;
        [Display(ShortName = "コード")]
        public string? Code
        {
            set { code = value; NotifyPropertyChanged(nameof(Code)); }
            get => code;
        }

        string? name;
        [Display(ShortName = "名称")]
        public string? Name
        {
            set { name = value; NotifyPropertyChanged(nameof(Name)); }
            get => name;
        }

        int? price1;
        [Display(ShortName = "仕入単価")]
        public int? Price1
        {
            set { price1 = value; NotifyPropertyChanged(nameof(Price1)); }
            get => price1;
        }

        int? price2;
        [Display(ShortName = "売上単価")]
        public int? Price2
        {
            set { price2 = value; NotifyPropertyChanged(nameof(Price2)); }
            get => price2;
        }

        int? quantity;
        [Display(ShortName = "数量")]
        public int? Quantity
        {
            set { quantity = value; NotifyPropertyChanged(nameof(Quantity)); }
            get => quantity;
        }

        public event PropertyChangedEventHandler? PropertyChanged;
        protected void NotifyPropertyChanged(string propertyName)
        {
            PropertyChanged?.Invoke(this,
                new PropertyChangedEventArgs(propertyName));
        }
    }

    public class SaleCollection : ObservableCollection<Sale>
    {
        public SaleCollection()
        {
            Add(new Sale { Code = "A001", Name = "えごま", 
                Price1 = 120, Price2 = 240, Quantity = 100 });
            Add(new Sale { Code = "A002", Name = "グレープシード",
                Price1 = 120, Price2 = 280, Quantity = 100 });
            Add(new Sale { Code = "B001", Name = "ウォールナッツ",
                Price1 = 1000, Price2 = 2400, Quantity = 50 });
            Add(new Sale { Code = "B002", Name = "ココナッツ", 
                Price1 = 4000, Price2 = 7000, Quantity = 60 });
            Add(new Sale { Code = "B003", Name = "スイートアーモンド", 
                Price1 = 90, Price2 = 180, Quantity = 2000 });
            Add(new Sale { Code = "C001", Name = "オリーブ", 
                Price1 = 2000, Price2 = 4000, Quantity = 100 });
            Add(new Sale { Code = "C002", Name = "ビーワックス", 
                Price1 = 1500, Price2 = 3200, Quantity = 80 });
            Add(new Sale { Code = "C003", Name = "馬油", 
                Price1 = 3200, Price2 = 7000, Quantity = 60 });
        }
    }
}

<Window
        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:SpreadGrid_net8"
        xmlns:sg="http://schemas.grapecity.com/windows/spreadgrid/2012"
        d:DataContext="{d:DesignInstance Type=local:SaleCollection}"
        x:Class="SpreadGrid_net8.MainWindow"
        mc:Ignorable="d"
        Title="MainWindow" Height="420" Width="600" 
        WindowStartupLocation="CenterScreen">
    <Window.Resources>
        <local:SaleCollection x:Key="SaleCollection"/>
    </Window.Resources>
    <Grid>
        <sg:GcSpreadGrid x:Name="GcSpreadGrid" 
                         AutoGenerateColumns="False" 
                         ItemsSource="{DynamicResource SaleCollection}" 
                         LayoutMode="Template">
            <sg:GcSpreadGrid.Columns>
                <sg:Column Locked="True">
                    <sg:Column.DataField>
                        <sg:BindingDataField Binding="{Binding Code}"/>
                    </sg:Column.DataField>
                </sg:Column>
                <sg:Column Locked="True" Background="Khaki">
                    <sg:Column.DataField>
                        <sg:BindingDataField Binding="{Binding Name}"/>
                    </sg:Column.DataField>
                </sg:Column>
                <sg:Column>
                    <sg:Column.DataField>
                        <sg:BindingDataField Binding="{Binding Price1}"/>
                    </sg:Column.DataField>
                    <sg:Column.CellType>
                        <sg:GeneralCellType FormatString="#,##0 円"/>
                    </sg:Column.CellType>
                </sg:Column>
                <sg:Column>
                    <sg:Column.DataField>
                        <sg:BindingDataField Binding="{Binding Price2}"/>
                    </sg:Column.DataField>
                    <sg:Column.CellType>
                        <sg:GeneralCellType FormatString="#,##0 円"/>
                    </sg:Column.CellType>
                </sg:Column>
                <sg:Column>
                    <sg:Column.DataField>
                        <sg:BindingDataField Binding="{Binding Quantity}"/>
                    </sg:Column.DataField>
                    <sg:Column.CellType>
                        <sg:GeneralCellType FormatString="#,##0"/>
                    </sg:Column.CellType>
                </sg:Column>
                <sg:Column Name="Sales" 
                           Locked="True" 
                           Header="売上" 
                           Foreground="Blue"
                           Formula="Price2*Quantity">
                    <sg:Column.CellType>
                        <sg:GeneralCellType FormatString="#,##0 円"/>
                    </sg:Column.CellType>
                </sg:Column>
                <sg:Column Name="Profit" 
                           Locked="True" 
                           Header="粗利"
                           Formula="(Price2 - Price1)*Quantity">
                    <sg:Column.CellType>
                        <sg:GeneralCellType FormatString="#,##0 円"/>
                    </sg:Column.CellType>
                </sg:Column>
            </sg:GcSpreadGrid.Columns>
            <sg:GcSpreadGrid.LayoutTemplate>
                <sg:LayoutTemplate>
                    <sg:LayoutTemplate.ColumnDefinitions>
                        <sg:TemplateColumnDefinition Width="90"/>
                        <sg:TemplateColumnDefinition Width="90"/>
                        <sg:TemplateColumnDefinition Width="90"/>
                        <sg:TemplateColumnDefinition Width="90"/>
                        <sg:TemplateColumnDefinition Width="100"/>
                    </sg:LayoutTemplate.ColumnDefinitions>
                    <sg:LayoutTemplate.RowTemplate>
                        <sg:RowTemplate>
                            <sg:RowTemplate.RowDefinitions>
                                <sg:TemplateRowDefinition Height="20"/>
                                <sg:TemplateRowDefinition Height="20"/>
                            </sg:RowTemplate.RowDefinitions>
                            <sg:RowTemplate.Cells>
                                <sg:CellTemplate RowIndex="0" 
                                                 ColumnIndex="0" 
                                                 DataColumnName="Code" 
                                                 RowSpan="2"/>
                                <sg:CellTemplate RowIndex="0" 
                                                 ColumnIndex="1" 
                                                 DataColumnName="Name" 
                                                 ColumnSpan="2"/>
                                <sg:CellTemplate RowIndex="0" 
                                                 ColumnIndex="3" 
                                                 DataColumnName="Quantity" 
                                                 RowSpan="2"/>
                                <sg:CellTemplate RowIndex="0" 
                                                 ColumnIndex="4" 
                                                 DataColumnName="Sales"/>
                                <sg:CellTemplate RowIndex="1" 
                                                 ColumnIndex="1" 
                                                 DataColumnName="Price1"/>
                                <sg:CellTemplate RowIndex="1" 
                                                 ColumnIndex="2" 
                                                 DataColumnName="Price2"/>
                                <sg:CellTemplate RowIndex="1" 
                                                 ColumnIndex="4" 
                                                 DataColumnName="Profit"/>
                            </sg:RowTemplate.Cells>
                        </sg:RowTemplate>
                    </sg:LayoutTemplate.RowTemplate>
                </sg:LayoutTemplate>
            </sg:GcSpreadGrid.LayoutTemplate>
        </sg:GcSpreadGrid>
    </Grid>
</Window>

・・・（中略）・・・
        <sg:GcSpreadGrid x:Name="GcSpreadGrid" 
                         AutoGenerateColumns="False" 
                         ItemsSource="{DynamicResource SaleCollection}" 
                         LayoutMode="Template">

・・・（中略）・・・

・・・（中略）・・・
                <sg:Column Name="Sales" 
                           ・・・（中略）・・・
                           Formula="Price2*Quantity">
                           ・・・（中略）・・・
                </sg:Column>
                <sg:Column Name="Profit" 
                           ・・・（中略）・・・
                           Formula="(Price2 - Price1)*Quantity">
                           ・・・（中略）・・・
                </sg:Column>
・・・（中略）・・・

using GrapeCity.Wpf.SpreadSheet;
using System.Windows;

namespace SpreadSheet_net8
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();

            // シートの設定
            var sheet = GcSpreadSheet.Workbook.ActiveSheet;
            sheet.ColumnCount = 10;
            sheet.RowCount = 100;
            SetData(sheet);
            SetOutline(sheet);
        }

        public void SetData(GrapeCity.Spreadsheet.IWorksheet sheet)
        {
            var baseData = new[] 
            { 
                "a1", "a2", "A", "b1", "b2", "B", "AB", "c1", "c2", "C"
            };

            // 列ヘッダの設定
            for (var i = 0; i < sheet.ColumnCount; i++)
            {
                sheet.ColumnHeader.Cells[i].Value = baseData[i];
            }

            // 値の設定
            for (var i = 0; i < sheet.RowCount; i++)
            {
                for (var j = 0; j < sheet.ColumnCount; j++)
                {
                    sheet.SetValue(i, j, $"{baseData[j]}_{i + 1}");
                }
            }
        }

        public void SetOutline(GrapeCity.Spreadsheet.IWorksheet sheet)
        {
            // アウトライン行の設定
            for (var i = 0; i < 10; i++)
            {
                sheet.Range($"{(i * 10) + 1}:{(i * 10) + 9}").Group();
            }

            // アウトライン列の設定
            sheet.Range("A:F").Group();
            sheet.Range("A:B").Group();
            sheet.Range("D:E").Group();
            sheet.Range("H:I").Group();
        }
    }
}