Question

I’m creating an Excel chart using C++. My problem is that I want to create multiple charts in same workbook.
This is my code:

    CoInitialize(NULL);
    Excel::_ApplicationPtr XL;
    XL.CreateInstance(L"Excel.Application");
    XL->Visible=true;
            XL->Workbooks->Add(Excel::xlWorksheet);
    Excel::_WorksheetPtr pSheet = XL->ActiveSheet;
            pSheet->Name = "Name";
            ...
            Excel::_ChartPtr pChart=XL->ActiveWorkbook->Charts->Add();
            pChart->Name =arr1;
            ...
            CoUninitialize();

… represents part of code where I fill table with data.
When I run it just once it creates new workbook with one worksheet and one plot. But when I want to put it inside for loop it opens multiple excel workbooks, all with pair sheet/plot. But I want them all to be inside one workbook.
Btw, I put for loop after this line: XL->Visible=true; and finish it before CoUninitialize();.

Thanks for the help!

Answer 1

Well, I don’t know the Excel COM API, and it’s been ages since I’ve used COM the last time myself, but, I think it’s obvious, that those statements

XL->Workbooks->Add(Excel::xlWorksheet);
Excel::_WorksheetPtr pSheet = XL->ActiveSheet;
pSheet->Name = "Name";

instruct Excel to add a new workbook (Workbooks is in the plural, and its Add methods is reasonable to assume to create a new one), in which you then create a new sheet.

Given this statement

Excel::_ChartPtr pChart = XL->ActiveWorkbook->Charts->Add();

I assume there should be also a XL->ActiveWorkbook->Sheets with a method Add(), that creates a new sheet in the current workbook, returning a pointer to it. So instead of XL->Workbooks->Add I’d try XL->ActiveWorkbook->Sheets->Add() to create a new sheet in the currently active workbook.

Note that I didn’t read any documentation for this answer, this is just my assumptions from the naming of the methods and knowing the way Microsoft OOP schemes used to work (years ago).