如何检索原先的Task Manager应用程序使用的任务列表

原先的Task Manager应用程序显示顶层窗口的列表。为了显示该列表，窗口
必须可见、包含一个标题以及不能被其他窗口拥有。调用CWnd:: GetWindow可以
检索顶层窗口的列表，调用IsWindowVisible、GetWindowTextLength以及GetOwner
void GetTadkList (CListBox&list)
{
     //Get first Window in window list.
     ASSERT_VALID (AfxGetMainWnd ());
     //Walk window list.
     while (pWnd)
     {
         // I window visible, has a caption, and does not have an owner?
         if (pWnd ->IsWindowVisible () &&
         if (pWnd ->IsWindowVisible () &&
            pWnd ->GetWindowTextLength () &&! pWnd ->GetOwner ())
         {
            //Add caption o window to list box.
            pWnd ->GetWindowText  (strCaption);
            list.AddString (strCaption);
         }
         //Get next window in window list.
         pWnd=pWnd->GetWindow (GW_HWNDNEXT);
     }