将二维数组写进excel中 C++，不使用第三方库

在C++中，可以使用Windows API来操作Excel，以下是一个示例代码，可以将二维数组写入Excel中：

#include <Windows.h>
#include <string>

void writeToExcel(int** data, int rows, int cols, std::string fileName)
{
    // 初始化COM库
    CoInitialize(NULL);

    // 创建Excel应用程序对象
    IDispatch* pExcelApp;
    CLSID clsid;
    CLSIDFromProgID(L"Excel.Application", &clsid);
    CoCreateInstance(clsid, NULL, CLSCTX_LOCAL_SERVER, IID_IDispatch, (void**)&pExcelApp);

    // 设置Visible属性为true，即可看到Excel打开的界面
    VARIANT var;
    var.vt = VT_BOOL;
    var.boolVal = TRUE;
    IDispatch* pExcelAppDisp;
    pExcelApp->QueryInterface(IID_IDispatch, (void**)&pExcelAppDisp);
    DISPID dispid;
    LPOLESTR szMember = L"Visible";
    pExcelAppDisp->GetIDsOfNames(IID_NULL, &szMember, 1, LOCALE_SYSTEM_DEFAULT, &dispid);
    pExcelAppDisp->Invoke(dispid, IID_NULL, LOCALE_SYSTEM_DEFAULT, DISPATCH_PROPERTYPUT, &var, NULL, NULL, NULL);

    // 获取Workbooks集合对象
    IDispatch* pWorkbooks;
    szMember = L"Workbooks";
    pExcelAppDisp->GetIDsOfNames(IID_NULL, &szMember, 1, LOCALE_SYSTEM_DEFAULT, &dispid);
    VARIANT result;
    pExcelAppDisp->Invoke(dispid, IID_NULL, LOCALE_SYSTEM_DEFAULT, DISPATCH_PROPERTYGET, &result, NULL, NULL, NULL);
    pWorkbooks = result.pdispVal;

    // 打开Excel文件或创建一个新文件
    IDispatch* pWorkbook;
    VARIANT vFileName;
    vFileName.vt = VT_BSTR;
    vFileName.bstrVal = SysAllocStringLen(NULL, fileName.size());
    MultiByteToWideChar(CP_ACP, 0, fileName.c_str(), fileName.size(), vFileName.bstrVal, fileName.size());
    szMember = L"Open";
    pWorkbooks->GetIDsOfNames(IID_NULL, &szMember, 1, LOCALE_SYSTEM_DEFAULT, &dispid);
    pWorkbooks->Invoke(dispid, IID_NULL, LOCALE_SYSTEM_DEFAULT, DISPATCH_METHOD, &result, NULL, NULL, NULL);
    pWorkbook = result.pdispVal;

    // 获取Worksheets集合对象
    IDispatch* pWorksheets;
    szMember = L"Worksheets";
    pWorkbook->GetIDsOfNames(IID_NULL, &szMember, 1, LOCALE_SYSTEM_DEFAULT, &dispid);
    pWorkbook->Invoke(dispid, IID_NULL, LOCALE_SYSTEM_DEFAULT, DISPATCH_PROPERTYGET, &result, NULL, NULL, NULL);
    pWorksheets = result.pdispVal;

    // 获取第一个Worksheet对象
    IDispatch* pWorksheet;
    szMember = L"Item";
    VARIANT index;
    index.vt = VT_I4;
    index.lVal = 1;
    pWorksheets->GetIDsOfNames(IID_NULL, &szMember, 1, LOCALE_SYSTEM_DEFAULT, &dispid);
    pWorksheets->Invoke(dispid, IID_NULL, LOCALE_SYSTEM_DEFAULT, DISPATCH_PROPERTYGET, &result, 1, &index, NULL);
    pWorksheet = result.pdispVal;

    // 将数据写入Worksheet中
    for (int i = 0; i < rows; i++)
    {
        for (int j = 0; j < cols; j++)
        {
            VARIANT value;
            value.vt = VT_I4;
            value.lVal = data[i][j];
            szMember = L"Cells";
            pWorksheet->GetIDsOfNames(IID_NULL, &szMember, 1, LOCALE_SYSTEM_DEFAULT, &dispid);
            VARIANT xIndex;
            xIndex.vt = VT_I4;
            xIndex.lVal = i + 1;
            VARIANT yIndex;
            yIndex.vt = VT_I4;
            yIndex.lVal = j + 1;
            VARIANT cell;
            VARIANT params[2] = { xIndex, yIndex };
            pWorksheet->Invoke(dispid, IID_NULL, LOCALE_SYSTEM_DEFAULT, DISPATCH_PROPERTYGET, &cell, 2, params, NULL);
            szMember = L"Value";
            cell.pdispVal->GetIDsOfNames(IID_NULL, &szMember, 1, LOCALE_SYSTEM_DEFAULT, &dispid);
            cell.pdispVal->Invoke(dispid, IID_NULL, LOCALE_SYSTEM_DEFAULT, DISPATCH_PROPERTYPUT, &value, NULL, NULL, NULL);
        }
    }

    // 保存并关闭Excel文件
    szMember = L"Save";
    pWorkbook->GetIDsOfNames(IID_NULL, &szMember, 1, LOCALE_SYSTEM_DEFAULT, &dispid);
    pWorkbook->Invoke(dispid, IID_NULL, LOCALE_SYSTEM_DEFAULT, DISPATCH_METHOD, NULL, NULL, NULL, NULL);
    szMember = L"Close";
    pWorkbook->GetIDsOfNames(IID_NULL, &szMember, 1, LOCALE_SYSTEM_DEFAULT, &dispid);
    pWorkbook->Invoke(dispid, IID_NULL, LOCALE_SYSTEM_DEFAULT, DISPATCH_METHOD, NULL, NULL, NULL, NULL);

    // 释放COM资源
    pExcelAppDisp->Release();
    pExcelApp->Release();
    CoUninitialize();
}

调用示例：

int data[3][4] = {
    {1, 2, 3, 4},
    {5, 6, 7, 8},
    {9, 10, 11, 12}
};
writeToExcel((int**)data, 3, 4, "test.xlsx");

该示例代码中，使用了Windows API的COM接口来操作Excel，实现了将二维数组写入Excel的功能。