[面试] C/C++ —— MFC（三）

CWnd 窗口基类的仿真

class CWnd
{
public:
BOOL CreateEx( DWORD dwExStyle,      // extended window style
...
);
BOOL ShowWindow(int nCmdShow);
BOOL UpdateWindow();
public:
HWND m_hWnd;
};

BOOL CWnd::CreateEx(DWORD dwExStyle,      // extended window style
....
)
{
m_hWnd = ::CreateWindowEx(dwExStyle, ....);
return m_hWnd ? true:false;
}

BOOL CWnd::ShowWindow(int nCmdShow)
{
return ::ShowWindow(m_hWnd, nCmdShow);
}

BOOL CWnd::UpdateWindow()
{
return ::UpdateWindow(m_hWnd);
}

int WINAPI WinMain(  HINSTANCE hInstance, ....)
{

WNDCLASS wndcls;
wndcls.cbClsExtra = 0;
wndcls.cbWndExtra = 0;
// ...
RegisterClass(&wndcls);
CWnd wnd;
wnd.CreateEx(...);
wnd.ShowWindow(SW_SHOWNORMAL);
wnd.UpdateWindow();
...
}

C++ 对象（CWnd）与窗口之间的关系

public:
HWND m_hWnd;