Electron.NET/ElectronNET.WebApp/Controllers/ClipboardController.cs

using Microsoft.AspNetCore.Mvc;
using ElectronNET.API;
using System.Linq;

namespace ElectronNET.WebApp.Controllers
{
    public class ClipboardController : Controller
    {
        public IActionResult Index()
        {
            Electron.IpcMain.On("copy-to", (text) => 
            {
                Electron.Clipboard.WriteText(text.ToString());
            });

            Electron.IpcMain.On("paste-to", async (text) =>
            {
                Electron.Clipboard.WriteText(text.ToString());
                string pasteText = await Electron.Clipboard.ReadTextAsync();

                var mainWindow = Electron.WindowManager.BrowserWindows.First();
                Electron.IpcMain.Send(mainWindow, "paste-from", pasteText);
            });

            return View();
        }
    }
}