C语言 Win32 api Worksheets 读写excel表格实例

以下是一个利用 C 语言 Win32 API 实现读写 Excel 表格的示例：

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

void ReadExcel()
{
    LPDISPATCH lpDisp;
    VARIANT var;
    CLSID clsid;
    HRESULT hr;
    LPTSTR pszFile = TEXT("test.xls");

    // 初始化 COM 库
    CoInitialize(NULL);

    // 获取 Excel 应用程序对象
    hr = CLSIDFromProgID(L"Excel.Application", &clsid);
    if (FAILED(hr))
    {
        printf("Failed to get Excel Application CLSID!\n");
        return;
    }
    hr = CoCreateInstance(&clsid, NULL, CLSCTX_LOCAL_SERVER, &IID_IDispatch, (void**)&lpDisp);
    if (FAILED(hr))
    {
        printf("Failed to create Excel Application object!\n");
        return;
    }

    // 打开 Excel 文件
    VARIANT vtFalse = {0};
    vtFalse.vt = VT_BOOL;
    vtFalse.boolVal = VARIANT_FALSE;
    VARIANT vtFileName;
    vtFileName.vt = VT_BSTR;
    vtFileName.bstrVal = SysAllocString(pszFile);
    hr = IDispatch_Invoke(lpDisp, 0x783, &IID_NULL, LOCALE_SYSTEM_DEFAULT, DISPATCH_METHOD, &vtFalse, NULL, NULL, NULL);
    if (FAILED(hr))
    {
        printf("Failed to open Excel file %s!\n", pszFile);
        return;
    }

    // 获取工作表对象
    IDispatch* pWorkbook = NULL;
    hr = IDispatch_Invoke(lpDisp, 0x50, &IID_NULL, LOCALE_SYSTEM_DEFAULT, DISPATCH_PROPERTYGET, NULL, NULL, NULL, &var);
    if (FAILED(hr))
    {
        printf("Failed to get Workbooks object!\n");
        return;
    }
    pWorkbook = var.pdispVal;
    if (!pWorkbook)
    {
        printf("Failed to get Workbook object!\n");
        return;
    }
    IDispatch* pWorksheet = NULL;
    VARIANT vtIndex;
    vtIndex.vt = VT_I4;
    vtIndex.lVal = 1;
    hr = IDispatch_Invoke(pWorkbook, 0x22e, &IID_NULL, LOCALE_SYSTEM_DEFAULT, DISPATCH_PROPERTYGET, &vtIndex, NULL, NULL, &var);
    if (FAILED(hr))
    {
        printf("Failed to get Worksheet object!\n");
        return;
    }
    pWorksheet = var.pdispVal;
    if (!pWorksheet)
    {
        printf("Failed to get Worksheet object!\n");
        return;
    }

    // 读取单元格数据
    VARIANT vtRange;
    vtRange.vt = VT_BSTR;
    vtRange.bstrVal = SysAllocString(L"A1");
    hr = IDispatch_Invoke(pWorksheet, 0x6c, &IID_NULL, LOCALE_SYSTEM_DEFAULT, DISPATCH_PROPERTYGET, &vtRange, NULL, &var, NULL);
    if (FAILED(hr))
    {
        printf("Failed to get cell value!\n");
        return;
    }
    printf("A1: %ls\n", var.bstrVal);

    // 写入单元格数据
    VARIANT vtValue;
    vtValue.vt = VT_BSTR;
    vtValue.bstrVal = SysAllocString(L"Hello, world!");
    hr = IDispatch_Invoke(pWorksheet, 0x6c, &IID_NULL, LOCALE_SYSTEM_DEFAULT, DISPATCH_PROPERTYPUT, &vtRange, &vtValue, NULL, NULL);
    if (FAILED(hr))
    {
        printf("Failed to set cell value!\n");
        return;
    }

    // 保存并关闭 Excel 文件
    hr = IDispatch_Invoke(pWorkbook, 0x1f4, &IID_NULL, LOCALE_SYSTEM_DEFAULT, DISPATCH_METHOD, &vtFalse, NULL, NULL, NULL);
    if (FAILED(hr))
    {
        printf("Failed to save Excel file %s!\n", pszFile);
        return;
    }
    hr = IDispatch_Invoke(pWorkbook, 0x1f3, &IID_NULL, LOCALE_SYSTEM_DEFAULT, DISPATCH_METHOD, NULL, NULL, NULL, NULL);
    if (FAILED(hr))
    {
        printf("Failed to close Excel file %s!\n", pszFile);
        return;
    }

    // 释放资源
    SysFreeString(vtFileName.bstrVal);
    SysFreeString(vtRange.bstrVal);
    SysFreeString(vtValue.bstrVal);
    pWorksheet->Release();
    pWorkbook->Release();
    lpDisp->Release();

    // 反初始化 COM 库
    CoUninitialize();
}

int main()
{
    ReadExcel();
    return 0;
}

该示例主要利用了 Excel 应用程序对象和工作表对象的 IDispatch 接口来实现读写 Excel 表格。其中，通过调用 `CLSIDFromProgID` 和 `CoCreateInstance` 获取 Excel 应用程序对象，然后通过调用 `IDispatch_Invoke` 方法打开 Excel 文件和获取工作表对象；接着，通过调用 `IDispatch_Invoke` 方法获取单元格数据和写入单元格数据；最后，通过调用 `IDispatch_Invoke` 方法保存并关闭 Excel 文件，释放资源并反初始化 COM 库。