c++ - AccessibleObjectFromWindow 返回 E_FAIL 代码

Question

请检查以下代码，它应该连接到当前正在运行的 Excel:

#include <windows.h>
#include <oleacc.h>
#import "C:\Program Files (x86)\Common Files\microsoft shared\OFFICE14\MSO.DLL" no_implementation rename("RGB", "ExclRGB") rename("DocumentProperties", "ExclDocumentProperties") rename("SearchPath", "ExclSearchPath")
#import "C:\Program Files (x86)\Common Files\microsoft shared\VBA\VBA6\VBE6EXT.OLB" no_implementation
#import "C:\Program Files (x86)\Microsoft Office\Office14\EXCEL.EXE" rename("DialogBox", "ExclDialogBox") rename("RGB", "ExclRGB") rename("CopyFile", "ExclCopyFile") rename("ReplaceText", "ExclReplaceText")

BOOL CALLBACK EnumChildProc(HWND hwnd, LPARAM)
{
   WCHAR szClassName[64];
   if(GetClassNameW(hwnd, szClassName, 64))
   {
      if(_wcsicmp(szClassName, L"EXCEL7") == 0)
      {
         //Get AccessibleObject
         Excel::Window* pWindow = NULL;
         HRESULT hr = AccessibleObjectFromWindow(hwnd, OBJID_NATIVEOM, __uuidof(Excel::Window), (void**)&pWindow);
         if(hr == S_OK)
         {
            //Excel object is now in pWindow pointer, from this you can obtain the document or application
            Excel::_Application* pApp = NULL;
            pApp = pWindow->GetApplication();
            pWindow->Release();
         }
         return false;     // Stops enumerating through children
      }
   }
   return true;
}

int main( int argc, CHAR* argv[])
{
    //The main window in Microsoft Excel has a class name of XLMAIN
    HWND excelWindow = FindWindow(L"XLMAIN", NULL);
    //Use the EnumChildWindows function to iterate through all child windows until we find _WwG
    EnumChildWindows(excelWindow, (WNDENUMPROC) EnumChildProc, (LPARAM)1);
    return 0;
}

事实是 Excel 确实在当前时刻运行，但 AccessibleObjectFromWindow 返回 E_FAIL。我还尝试循环运行此代码并切换到 Excel 以专注于它的应用程序。同理，AccessibleObjectFromWindow 返回 E_FAIL。我现在正在互联网上搜索答案，但之前找到的所有答案都没有给我任何帮助。因此，如果有人可以提供解释，我们将不胜感激。

Answer 1

从一些代码示例中找到答案:

int main( int argc, CHAR* argv[])
{
    CoInitialize( NULL );
    ...

在开始使用任何其他对象之前通过调用 CoInitialize(NULL) 解决了该问题。