Build your own cloud spreadsheet (like Microsoft Excel, google sheets)

https://www.codeproject.com/Articles/892137/Online-Spreadsheet-a-low-latency-html-websocket-Cl

Dapper的WebForm和MVC範例

WebForm
https://github.com/dotnetgenetics/ASP.NET-WebForm-Dapper

MVC
https://github.com/dotnetgenetics/ASP.NETMVCDapper

ReoGrid：可以把WinForm做成類似Excel xlsx編輯器的套件

https://github.com/unvell/ReoGrid

可以把WinForm做成類似Excel xlsx編輯器的套件
完全免費，MIT授權，支援Formula，電腦不需要安裝Excel
https://reogrid.net/document/formula/

安裝套件 https://reogrid.net/document/installation/
ReoGrid for Windows Form
PM> Install-Package unvell.ReoGrid.dll

ReoGrid for WPF
PM> Install-Package unvell.ReoGridWPF.dll

官方文件:
https://reogrid.net/document/

DEMO(官方的範例滿多的)
https://github.com/unvell/ReoGrid/tree/master/Demo

ReoScript
https://reogrid.net/document/script-execution/

其他參考資料:
http://necotech.org/archives/365
https://www.unvell.com/jp/
https://www.codeproject.com/Articles/691749/Free-NET-Spreadsheet-Control

範例(視窗載入時建立ReoGridControl):
        private void Form1_Load(object sender, EventArgs e)
        {
            //https://www.codeproject.com/Articles/691749/Free-NET-Spreadsheet-Control
            // create instance
            var grid = new ReoGridControl()
            {
                // put to fill the parent control
                Dock = DockStyle.Fill,
            };


            this.Controls.Add(grid);

           
        }

如果要編譯ReoGrid原始碼，舊版Visual Studio (比如2013)認不得$
請安裝新版Microsoft.Net.Compilers
https://www.nuget.org/packages/Microsoft.Net.Compilers/

其他:
SpreadsheetGear(付費)
https://www.spreadsheetgear.com

Spreadsheet.net (付費)

https://www.grapecity.com/en/spreadnet

SpreadsheetGear vs. SyncFusion vs. ComponentOne
https://josephfluckiger.blogspot.com/2013/03/spreadsheetgear-vs-syncfusion-vs.html