C语言 DISPID_WORKBOOKS_OPEN 打开excel表格 读取表格内容 读取Rows

使用C语言打开Excel表格并读取表格内容需要使用Microsoft Excel Object Library，以下是一个简单的例子：

#include <windows.h>
#include <ole2.h>
#include "excel9.h" // Excel 2000
#pragma comment(lib, "ole32.lib")
#pragma comment(lib, "oleaut32.lib")
#pragma comment(lib, "excel9.lib")

int main()
{
    // 初始化COM
    CoInitialize(NULL);

    // 创建Excel应用程序对象
    IDispatch* pExcel;
    CoCreateInstance(CLSID_Application, NULL, CLSCTX_LOCAL_SERVER, IID_IDispatch, (void**)&pExcel);

    // 获取Workbooks集合对象
    IDispatch* pWorkbooks;
    {
        VARIANT result;
        VariantInit(&result);
        DISPPARAMS params = { NULL, NULL, 0, 0 };
        pExcel->Invoke(DISPID_WORKBOOKS, IID_NULL, LOCALE_USER_DEFAULT, DISPATCH_PROPERTYGET, &params, &result, NULL, NULL);
        pWorkbooks = result.pdispVal;
    }

    // 打开Excel表格
    IDispatch* pWorkbook;
    {
        VARIANT result;
        VariantInit(&result);
        DISPPARAMS params = { NULL, NULL, 0, 0 };
        VARIANT filename;
        filename.vt = VT_BSTR;
        filename.bstrVal = SysAllocString(L"path/to/your/excel/file.xlsx");
        params.cArgs = 1;
        params.rgvarg = &filename;
        pWorkbooks->Invoke(DISPID_WORKBOOKS_OPEN, IID_NULL, LOCALE_USER_DEFAULT, DISPATCH_METHOD, &params, &result, NULL, NULL);
        pWorkbook = result.pdispVal;
    }

    // 获取Worksheets集合对象
    IDispatch* pWorksheets;
    {
        VARIANT result;
        VariantInit(&result);
        DISPPARAMS params = { NULL, NULL, 0, 0 };
        pWorkbook->Invoke(DISPID_WORKBOOK_WORKSHEETS, IID_NULL, LOCALE_USER_DEFAULT, DISPATCH_PROPERTYGET, &params, &result, NULL, NULL);
        pWorksheets = result.pdispVal;
    }

    // 获取第一个Worksheet对象
    IDispatch* pWorksheet;
    {
        VARIANT result;
        VariantInit(&result);
        DISPPARAMS params = { NULL, NULL, 0, 0 };
        VARIANT index;
        index.vt = VT_I4;
        index.lVal = 1;
        params.cArgs = 1;
        params.rgvarg = &index;
        pWorksheets->Invoke(DISPID_VALUE, IID_NULL, LOCALE_USER_DEFAULT, DISPATCH_PROPERTYGET, &params, &result, NULL, NULL);
        pWorksheet = result.pdispVal;
    }

    // 读取行数和列数
    int rowCount, colCount;
    {
        VARIANT result;
        VariantInit(&result);
        DISPPARAMS params = { NULL, NULL, 0, 0 };
        pWorksheet->Invoke(DISPID_VALUE, IID_NULL, LOCALE_USER_DEFAULT, DISPATCH_PROPERTYGET, &params, &result, NULL, NULL);
        IDispatch* pRange = result.pdispVal;
        VARIANT rowCountVar, colCountVar;
        VariantInit(&rowCountVar);
        VariantInit(&colCountVar);
        params.cArgs = 2;
        params.rgvarg = (VARIANTARG*)&rowCountVar;
        pRange->Invoke(DISPID_VALUE, IID_NULL, LOCALE_USER_DEFAULT, DISPATCH_PROPERTYGET, &params, &result, NULL, NULL);
        rowCount = rowCountVar.lVal;
        params.rgvarg = (VARIANTARG*)&colCountVar;
        pRange->Invoke(DISPID_VALUE, IID_NULL, LOCALE_USER_DEFAULT, DISPATCH_PROPERTYGET, &params, &result, NULL, NULL);
        colCount = colCountVar.lVal;
        pRange->Release();
    }

    // 读取数据
    for (int i = 1; i <= rowCount; i++)
    {
        for (int j = 1; j <= colCount; j++)
        {
            VARIANT result;
            VariantInit(&result);
            DISPPARAMS params = { NULL, NULL, 0, 0 };
            VARIANT row, col;
            row.vt = VT_I4;
            col.vt = VT_I4;
            row.lVal = i;
            col.lVal = j;
            params.cArgs = 2;
            params.rgvarg = (VARIANTARG*)&col;
            pWorksheet->Invoke(DISPID_VALUE, IID_NULL, LOCALE_USER_DEFAULT, DISPATCH_PROPERTYGET, &params, &result, NULL, NULL);
            IDispatch* pCell = result.pdispVal;
            BSTR value;
            pCell->Invoke(DISPID_VALUE, IID_NULL, LOCALE_USER_DEFAULT, DISPATCH_PROPERTYGET, &params, &result, NULL, NULL);
            value = result.bstrVal;
            printf("%S\t", value);
            SysFreeString(value);
            pCell->Release();
        }
        printf("\n");
    }

    // 释放资源
    pWorksheet->Release();
    pWorksheets->Release();
    pWorkbook->Release();
    pWorkbooks->Release();
    pExcel->Release();
    CoUninitialize();

    return 0;
}

这个例子使用了DISPID_WORKBOOKS_OPEN来打开Excel表格，然后通过DISPID_WORKBOOK_WORKSHEETS和DISPID_VALUE来获取第一个Worksheet对象，以及获取行数和列数。接着，它通过DISPID_VALUE和DISPATCH_PROPERTYGET来获取单元格的值。需要注意的是，对于每一个DISPATCH对象，我们都需要在使用完之后调用Release()方法来释放资源。