c++获取excel数据

要在 C++ 中获取 Excel 数据，我们可以使用 COM 接口。以下是一个示例代码，可以打开一个 Excel 文件，读取其中的数据并输出到控制台：

#include <windows.h>
#include <ole2.h>
#include <iostream>

void read_excel(const wchar_t* filename) {
    HRESULT hr;
    CoInitialize(NULL);

    // 创建 Excel 应用程序对象
    IDispatch* pExcelApp = NULL;
    hr = CoCreateInstance(CLSID_Application, NULL, CLSCTX_LOCAL_SERVER, IID_IDispatch, (void**)&pExcelApp);
    if (FAILED(hr)) {
        std::cout << "Failed to create Excel application object!" << std::endl;
        return;
    }

    // 打开 Excel 文件
    VARIANT varFilename;
    VariantInit(&varFilename);
    varFilename.vt = VT_BSTR;
    varFilename.bstrVal = SysAllocString(filename);

    IDispatch* pWorkbooks = NULL;
    hr = pExcelApp->GetTypeInfo()->InvokeMember(L"Workbooks", DISPATCH_PROPERTYGET, NULL, pExcelApp, NULL, &pWorkbooks, NULL, NULL);
    if (FAILED(hr)) {
        std::cout << "Failed to get Workbooks object!" << std::endl;
        pExcelApp->Release();
        return;
    }

    IDispatch* pWorkbook = NULL;
    hr = pWorkbooks->GetTypeInfo()->InvokeMember(L"Open", DISPATCH_METHOD, NULL, pWorkbooks, &varFilename, &pWorkbook, NULL, NULL);
    if (FAILED(hr)) {
        std::cout << "Failed to open Excel file!" << std::endl;
        pWorkbooks->Release();
        pExcelApp->Release();
        return;
    }

    // 获取第一个工作表
    IDispatch* pWorksheets = NULL;
    hr = pWorkbook->GetTypeInfo()->InvokeMember(L"Worksheets", DISPATCH_PROPERTYGET, NULL, pWorkbook, NULL, &pWorksheets, NULL, NULL);
    if (FAILED(hr)) {
        std::cout << "Failed to get Worksheets object!" << std::endl;
        pWorkbook->Release();
        pWorkbooks->Release();
        pExcelApp->Release();
        return;
    }

    IDispatch* pWorksheet = NULL;
    VARIANT varIndex;
    VariantInit(&varIndex);
    varIndex.vt = VT_I4;
    varIndex.lVal = 1;
    hr = pWorksheets->GetTypeInfo()->InvokeMember(L"Item", DISPATCH_PROPERTYGET, NULL, pWorksheets, &varIndex, &pWorksheet, NULL, NULL);
    if (FAILED(hr)) {
        std::cout << "Failed to get first worksheet!" << std::endl;
        pWorksheets->Release();
        pWorkbook->Release();
        pWorkbooks->Release();
        pExcelApp->Release();
        return;
    }

    // 获取数据
    IDispatch* pRange = NULL;
    hr = pWorksheet->GetTypeInfo()->InvokeMember(L"Range", DISPATCH_PROPERTYGET, NULL, pWorksheet, &varIndex, &pRange, NULL, NULL);
    if (FAILED(hr)) {
        std::cout << "Failed to get Range object!" << std::endl;
        pWorksheet->Release();
        pWorksheets->Release();
        pWorkbook->Release();
        pWorkbooks->Release();
        pExcelApp->Release();
        return;
    }

    VARIANT varValue;
    VariantInit(&varValue);
    hr = pRange->GetTypeInfo()->InvokeMember(L"Value", DISPATCH_PROPERTYGET, NULL, pRange, NULL, &varValue, NULL, NULL);
    if (FAILED(hr)) {
        std::cout << "Failed to get cell value!" << std::endl;
        pRange->Release();
        pWorksheet->Release();
        pWorksheets->Release();
        pWorkbook->Release();
        pWorkbooks->Release();
        pExcelApp->Release();
        return;
    }

    // 输出数据到控制台
    SAFEARRAY* pArray = varValue.parray;
    long num_rows, num_cols;
    SafeArrayGetUBound(pArray, 1, &num_rows);
    SafeArrayGetUBound(pArray, 2, &num_cols);
    for (long i = 0; i <= num_rows; i++) {
        for (long j = 0; j <= num_cols; j++) {
            VARIANT varCell;
            VariantInit(&varCell);
            long indices[2] = { i, j };
            SafeArrayGetElement(pArray, indices, &varCell);
            std::wcout << varCell.bstrVal << L"\t";
            VariantClear(&varCell);
        }
        std::wcout << std::endl;
    }

    // 释放资源
    VariantClear(&varValue);
    pRange->Release();
    pWorksheet->Release();
    pWorksheets->Release();
    pWorkbook->Release();
    pWorkbooks->Release();
    pExcelApp->Release();

    CoUninitialize();
}

int main() {
    read_excel(L"C:\\test.xlsx");
    return 0;
}

这段代码使用了 COM 接口来创建 Excel 应用程序对象，打开 Excel 文件，获取工作表和数据。对于每个单元格，我们可以使用 `SafeArrayGetElement` 函数从数组中获取数据。最后，我们释放所有使用的资源。