如何让全透明窗口响应鼠标消息

如

SetWindowLong(this->GetSafeHwnd(),GWL_EXSTYLE, 
  GetWindowLong(this->GetSafeHwnd(),GWL_EXSTYLE) | 0x80000); 
HINSTANCE hInst=LoadLibrary("User32.DLL"); 
if(hInst) 
{ 
  typedef BOOL (WINAPI * MYFUNC)(HWND,COLORREF,BYTE,DWORD); 
  MYFUNC fun=NULL; 

  //取得SetLayeredWindowAttributes函数指针 
  fun=(MYFUNC)GetProcAddress(hInst,"SetLayeredWindowAttributes"); 
  if(fun) 
  fun(this->GetSafeHwnd(),RGB(236,233,216),50,1); 
  FreeLibrary(hInst);

}

SetWindowPos(&CWnd::wndTopMost,0,0,0,0,SWP_NOMOVE|SWP_NOSIZE); 
//这是设置窗口透明的代码