C语言 GetIDsOfNames 获取Range Excel表格使用实例

以下是一个简单的 C 代码示例，演示如何使用 `GetIDsOfNames` 和 `Invoke` 方法来获取 Excel 表格中的 Range 对象，并设置单元格的值。

#include <stdio.h>
#include <windows.h>
#include "ole2.h"
#include "oleauto.h"

int main()
{
    HRESULT hr;
    CLSID clsid;
    IDispatch *pExcelApp = NULL, *pWorkbook = NULL, *pWorksheet = NULL, *pRange = NULL;
    VARIANT vtWorkbooks, vtWorkbook, vtWorksheets, vtWorksheet, vtRange, vtValue;

    // 初始化 COM 库
    hr = CoInitialize(NULL);
    if (FAILED(hr))
    {
        printf("CoInitialize failed: %x\n", hr);
        return 1;
    }

    // 获取 Excel 应用程序对象
    hr = CLSIDFromProgID(L"Excel.Application", &clsid);
    if (FAILED(hr))
    {
        printf("CLSIDFromProgID failed: %x\n", hr);
        CoUninitialize();
        return 1;
    }

    hr = CoCreateInstance(&clsid, NULL, CLSCTX_LOCAL_SERVER, &IID_IDispatch, (void **)&pExcelApp);
    if (FAILED(hr))
    {
        printf("CoCreateInstance failed: %x\n", hr);
        CoUninitialize();
        return 1;
    }

    // 打开工作簿
    vtWorkbooks.vt = VT_DISPATCH;
    vtWorkbooks.pdispVal = pExcelApp;
    hr = Invoke(pExcelApp, L"Workbooks", &vtWorkbooks, 1, &vtWorkbook);
    if (FAILED(hr))
    {
        printf("Invoke Workbooks failed: %x\n", hr);
        pExcelApp->Release();
        CoUninitialize();
        return 1;
    }

    hr = Invoke(pWorkbook, L"Open", L"C:\\test.xlsx", NULL, 0);
    if (FAILED(hr))
    {
        printf("Invoke Open failed: %x\n", hr);
        pWorkbook->Release();
        pExcelApp->Release();
        CoUninitialize();
        return 1;
    }

    // 获取工作表对象
    vtWorksheets.vt = VT_DISPATCH;
    vtWorksheets.pdispVal = pWorkbook;
    hr = Invoke(pWorkbook, L"Worksheets", &vtWorksheets, 1, &vtWorksheet);
    if (FAILED(hr))
    {
        printf("Invoke Worksheets failed: %x\n", hr);
        pWorkbook->Release();
        pExcelApp->Release();
        CoUninitialize();
        return 1;
    }

    // 获取 Range 对象
    vtRange.vt = VT_BSTR;
    vtRange.bstrVal = SysAllocString(L"A1:B2");
    hr = Invoke(pWorksheet, L"Range", &vtRange, 1, &vtRange);
    if (FAILED(hr))
    {
        printf("Invoke Range failed: %x\n", hr);
        pWorksheet->Release();
        pWorkbook->Release();
        pExcelApp->Release();
        CoUninitialize();
        return 1;
    }

    // 设置单元格的值
    vtValue.vt = VT_BSTR;
    vtValue.bstrVal = SysAllocString(L"Hello World!");
    hr = SetProperty(pRange, L"Value", &vtValue);
    if (FAILED(hr))
    {
        printf("SetProperty Value failed: %x\n", hr);
        pRange->Release();
        pWorksheet->Release();
        pWorkbook->Release();
        pExcelApp->Release();
        CoUninitialize();
        return 1;
    }

    // 释放所有对象
    VariantClear(&vtValue);
    VariantClear(&vtRange);
    pRange->Release();
    VariantClear(&vtWorksheet);
    pWorksheet->Release();
    VariantClear(&vtWorksheets);
    pWorkbook->Release();
    VariantClear(&vtWorkbook);
    pExcelApp->Release();
    CoUninitialize();

    return 0;
}

// Invoke 函数用于调用 COM 对象的方法
HRESULT Invoke(IDispatch *pObj, LPCWSTR szName, VARIANT *pvResult, int cArgs, ...)
{
    HRESULT hr;
    DISPID dispid;
    DISPPARAMS dispparams = {0};
    VARIANTARG *pArgs = NULL;
    EXCEPINFO excepinfo;

    // 获取方法的 DISPID
    hr = pObj->GetIDsOfNames(IID_NULL, (LPOLESTR *)&szName, 1, LOCALE_SYSTEM_DEFAULT, &dispid);
    if (FAILED(hr))
    {
        printf("GetIDsOfNames failed: %x\n", hr);
        return hr;
    }

    if (cArgs > 0)
    {
        pArgs = new VARIANTARG[cArgs];
        va_list marker;
        va_start(marker, cArgs);
        for (int i = 0; i < cArgs; i++)
        {
            pArgs[i] = va_arg(marker, VARIANTARG);
        }
        va_end(marker);
        dispparams.cArgs = cArgs;
        dispparams.rgvarg = pArgs;
    }

    // 调用方法
    hr = pObj->Invoke(dispid, IID_NULL, LOCALE_SYSTEM_DEFAULT, DISPATCH_METHOD, &dispparams, pvResult, &excepinfo, NULL);
    if (FAILED(hr))
    {
        printf("Invoke %S failed: %x\n", szName, hr);
        return hr;
    }

    if (pArgs != NULL)
    {
        delete[] pArgs;
    }

    return S_OK;
}

// SetProperty 函数用于设置 COM 对象的属性值
HRESULT SetProperty(IDispatch *pObj, LPCWSTR szName, VARIANT *pvValue)
{
    HRESULT hr;
    DISPID dispid;
    DISPID namedArgs[] = {DISPID_PROPERTYPUT};
    DISPPARAMS dispparams = {0};
    VARIANTARG rgvarg[2];
    EXCEPINFO excepinfo;

    // 获取属性的 DISPID
    hr = pObj->GetIDsOfNames(IID_NULL, (LPOLESTR *)&szName, 1, LOCALE_SYSTEM_DEFAULT, &dispid);
    if (FAILED(hr))
    {
        printf("GetIDsOfNames failed: %x\n", hr);
        return hr;
    }

    // 设置属性值
    rgvarg[1] = *pvValue;
    rgvarg[0].vt = VT_EMPTY;
    dispparams.cArgs = 1;
    dispparams.rgvarg = rgvarg;
    dispparams.cNamedArgs = 1;
    dispparams.rgdispidNamedArgs = namedArgs;
    hr = pObj->Invoke(dispid, IID_NULL, LOCALE_SYSTEM_DEFAULT, DISPATCH_PROPERTYPUT, &dispparams, NULL, &excepinfo, NULL);
    if (FAILED(hr))
    {
        printf("Invoke %S failed: %x\n", szName, hr);
        return hr;
    }

    return S_OK;
}

上述代码中的 `Invoke` 函数用于调用 COM 对象的方法，其中 `pObj` 参数为要调用的对象，`szName` 参数为方法名，`pvResult` 参数为返回值，`cArgs` 参数为参数个数，后面的可变参数为具体的参数。`SetProperty` 函数用于设置 COM 对象的属性值，其中 `pObj` 参数为要设置属性的对象，`szName` 参数为属性名，`pvValue` 参数为属性值。