Implementera anpassad beräkningsmotor för att utöka den standardmässiga beräkningsmotorn för Aspose.Cells med C++

#include <iostream>
#include <cwctype>
#include "Aspose.Cells.h"
#include <chrono>

using namespace Aspose::Cells;

class CustomEngine : public AbstractCalculationEngine
{
public:
    void Calculate(CalculationData& data) override
    {
        U16String funcName = data.GetFunctionName();
        std::u16string upperName;
        for (int i = 0; i < funcName.GetLength(); ++i)
        {
            upperName.push_back(std::towupper(funcName[i]));
        }
		if (upperName == u"TODAY")
		{
			auto now = std::chrono::system_clock::now();
			std::time_t now_time = std::chrono::system_clock::to_time_t(now);
			std::tm local_tm;

#ifdef _WIN32
			localtime_s(&local_tm, &now_time);
#else
			localtime_r(&now_time, &local_tm);
#endif

            Date today{ local_tm.tm_year + 1900, local_tm.tm_mon + 1, local_tm.tm_mday };
			data.SetCalculatedValue(Date{ today.year, today.month, today.day + 1 });
		}
    }

    bool GetProcessBuiltInFunctions() override { return true; }
};

class ImplementCustomCalculationEngine
{
public:
    static void Run()
    {
        Workbook workbook;
        Worksheet sheet = workbook.GetWorksheets().Get(0);
        Cell a1 = sheet.GetCells().Get(u"A1");
        Style style = a1.GetStyle();
        style.SetNumber(14);
        a1.SetStyle(style);
        a1.SetFormula(u"=TODAY()");
        workbook.CalculateFormula();
        std::cout << "The value of A1 with default calculation engine: " << a1.GetStringValue().ToUtf8() << std::endl;
        CustomEngine engine;
        CalculationOptions opts;
        opts.SetCustomEngine(&engine);
        workbook.CalculateFormula(opts);
        std::cout << "The value of A1 with custom calculation engine: " << a1.GetStringValue().ToUtf8() << std::endl;
        std::cout << "Press any key to continue..." << std::endl;
        std::cin.get();
    }
};

int main()
{
    Aspose::Cells::Startup();
    ImplementCustomCalculationEngine::Run();
    Aspose::Cells::Cleanup();
    return 0;
}