1.導入Excel類型庫
使用Visual C++的擴展指令#import導入Excel類型庫:
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#import "C:\\Program Files\\Common Files\\microsoft shared\\OFFICE14\\MSO.DLL" \
rename
(
"RGB"
,
"MsoRGB"
) \
rename
(
"SearchPath"
,
"MsoSearchPath"
)
#import "C:\\Program Files\\Common Files\\Microsoft Shared\\VBA\\VBA6\\VBE6EXT.OLB"
#import "C:\\Program Files\\Microsoft Office\\Office14\\EXCEL.EXE" \
rename
(
"DialogBox"
,
"ExcelDialogBox"
) \
rename
(
"RGB"
,
"ExcelRGB"
) \
rename
(
"CopyFile"
,
"ExcelCopyFile"
) \
rename
(
"ReplaceText"
,
"ExcelReplaceText"
) \
exclude(
"IFont"
,
"IPicture"
) no_dual_interfaces
|
#import指令會從指定的可執行文件,動態鏈接庫等COM組件中導出類型庫(type lib),在Debug和Release臨時目錄中生成對應的類型庫頭文件(type lib header file),以供C++程序使用。如以上三條指令在編譯后會生成excel.tlh, mso.lh和vbetext.olb三個頭文件,可以在Debug和Release目錄中找到。
2.訪問Excel暴露的COM對象
下面是一段比較完整的訪問Excel的實例代碼。首先用生成的數據填充單元格,然后用這些單元格的數據生成了一個圖表(Chart):
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try
{
Excel::_ApplicationPtr pExcelApp;
HRESULT
hr = pExcelApp.CreateInstance(L
"Excel.Application"
);
ATLASSERT(SUCCEEDED(hr));
pExcelApp->Visible =
true
;
// make Excel’s main window visible
Excel::_WorkbookPtr pWorkbook = pExcelApp->Workbooks->Open(lpszPathName);
// open excel file
Excel::_WorksheetPtr pWorksheet = pWorkbook->ActiveSheet;
pWorksheet->Name = L
"Chart Data"
;
Excel::RangePtr pRange = pWorksheet->Cells;
const
int
nplot = 100;
const
double
xlow = 0.0, xhigh = 20.0;
double
h = (xhigh-xlow)/(
double
)nplot;
pRange->Item[1][1] = L
"x"
;
// read/write cell’s data
pRange->Item[1][2] = L
"f(x)"
;
for
(
int
i=0;i<nplot;++i)
{
double
x = xlow+i*h;
pRange->Item[i+2][1] = x;
pRange->Item[i+2][2] =
sin
(x)*
exp
(-x);
}
Excel::RangePtr pBeginRange = pRange->Item[1][1];
Excel::RangePtr pEndRange = pRange->Item[nplot+1][2];
Excel::RangePtr pTotalRange =
pWorksheet->Range[(Excel::Range*)pBeginRange][(Excel::Range*)pEndRange];
Excel::_ChartPtr pChart = pExcelApp->ActiveWorkbook->Charts->Add();
// refer to :
// http://msdn.microsoft.com/en-us/library/microsoft.office.tools.excel.chart.chartwizard(v=vs.80).aspx
pChart->ChartWizard(
(Excel::Range*)pTotalRange,
(
long
)Excel::xlXYScatter,
6L,
(
long
)Excel::xlColumns,
1L,1L,
true
,
L
"My Graph"
,
L
"x"
,L
"f(x)"
);
pChart->Name = L
"My Data Plot"
;
pWorkbook->Close(VARIANT_TRUE);
// save changes
pExcelApp->Quit();
}
catch
(_com_error& error)
{
ATLASSERT(FALSE);
ATLTRACE2(error.ErrorMessage());
}
|
在這段代碼中,Excel::_ApplicationPtr , Excel::_WorkbookPtr 和 Excel::_WorksheetPtr 等均是Visual C++ 編譯器根據#import指令自動生成的智能指針,實際上就是C++模板類_com_ptr_t<T>的typedef,其定義可在excel.tlh等類型庫頭文件中找到。
另外,由於#import指令中沒有指定raw_interface_only修飾符,Visual C++對Excel的COM接口進行了適當的封裝,以簡化COM接口屬性和方法的調用,並且將HRESULT返回值都轉換成了C++異常,因此,上面的這段代碼不需要每一步都堅持HRESULT,而是改為捕獲C++異常。