EnumChildWindows never calls its callback - c++

Question

I'm trying to manipulate a specific Internet Explorer 11 window. Using WinSpy++ I find that
The top level window's class is an IEFrame with the title of the document as the text (as returned by GetWindowText)
The actual web view class is called "Internet Explorer_Server" and is a child of the former.
I wrote a simple test case for finding the web view of IE11 opened on "https://encrypted.google.com/" in three different ways:
HWND FindIE_A()
{
// Use FindWindow, works!
HWND hWndTop = ::FindWindowA( NULL, "Google - Internet Explorer" );
// Find the web view window, the callback (FindIEServer) is NEVER called!
HWND hWnd = NULL;
::EnumChildWindows( hWndTop, &FindIEServer, (LPARAM)&hWnd );
return hWnd;
}
HWND FindIE_B()
{
// Use EnumChildWindows with NULL as parent, works!
HWND hWndTop = NULL;
::EnumChildWindows( NULL, &FindIEMain, (LPARAM)&hWndTop );
// Find the web view window, the callback (FindIEServer) is NEVER called!
HWND hWnd = NULL;
::EnumChildWindows( hWndTop, &FindIEServer, (LPARAM)&hWnd );
return hWnd;
}
HWND FindIE_C()
{
// Simple EnumWindows, works!
HWND hWndTop = NULL;
::EnumWindows( &FindIEMain, (LPARAM)&hWndTop );
// Find the web view window, the callback (FindIEServer) is NEVER called!
HWND hWnd = NULL;
::EnumChildWindows( hWndTop, &FindIEServer, (LPARAM)&hWnd );
return hWnd;
}
The callbacks that are very simple; get a property from the window and compare against a hard-coded value:
BOOL CALLBACK FindIEServer( HWND hWnd, LPARAM lParam )
{
char className[64];
::GetClassNameA( hWnd, className, sizeof(className) );
if ( !strcmp( className, "Internet Explorer_Server" ) )
{
*(HWND*)lParam = hWnd;
return FALSE;
}
return TRUE;
}
BOOL CALLBACK FindIEMain( HWND hWnd, LPARAM lParam )
{
char text[128];
::GetWindowTextA( hWnd, text, sizeof(text) );
if ( !strcmp( text, "Google - Internet Explorer" ) )
{
*(HWND*)lParam = hWnd;
return FALSE;
}
return TRUE;
}
EnumChildWindows failed (by not calling the callback AT ALL!) every time when provided with a parent window. Why?

Answer 1

The problem is that when I look for the window title, I was assuming there was only one window with that title. However Internet Explorer does some shenanigans and creates multiple windows with the same title however only one of them has the class IEFrame.
It just so happens that the first window found was the wrong one, it didn't have any children (and thus EnumChildWindows doesn't have anything to iterate over). Just adding an extra check for title + class works.
However as #wakjah suggested, it is better integrate IE (or any other browser) directly into your code. With google I found lots of documentation on how to do this with both IE and Chrome.