1.导入Excel类型库
使用Visual C++的扩展指令#import导入Excel类型库:
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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
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#import指令会从指定的可执行文件,动态链接库等COM组件中导出类型库(type lib),在Debug和Release临时目录中生成对应的类型库头文件(type lib header file),以供C++程序使用。如以上三条指令在编译后会生成excel.tlh, mso.lh和vbetext.olb三个头文件,可以在Debug和Release目录中找到。
2.访问Excel暴露的COM对象
下面是一段比较完整的访问Excel的实例代码。首先用生成的数据填充单元格,然后用这些单元格的数据生成了一个图表(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());
} |
在这段代码中,Excel::_ApplicationPtr , Excel::_WorkbookPtr 和 Excel::_WorksheetPtr 等均是Visual C++ 编译器根据#import指令自动生成的智能指针,实际上就是C++模板类_com_ptr_t<T>的typedef,其定义可在excel.tlh等类型库头文件中找到。
另外,由于#import指令中没有指定raw_interface_only修饰符,Visual C++对Excel的COM接口进行了适当的封装,以简化COM接口属性和方法的调用,并且将HRESULT返回值都转换成了C++异常,因此,上面的这段代码不需要每一步都坚持HRESULT,而是改为捕获C++异常。