Get Child Window HWND

EnumWindow(hwnd_parent, Fun, lparam)

FindWindow(class_name, window_name)

FindWindowEx(hwnd_parent, xxx, class_name, window_name)

GetDlgItem(ID)

SendMessage()交互

1. 子窗口 没title.  FindWindow不好使

2. GetDlgItem只能通过控件ID获取控件, 不能获取 子窗口.

3. m_ie.Create(NULL, L"bb", WS_CHILD | WS_VISIBLE | WS_POPUP,  rect, this, 111);

    Create窗口的ID, GetWindowLong(hwnd, GWL_ID); 获取不到.    但tree可以获取到.