下面的代码将演示如何使用它们：(代码来自http://www.newlc.com/article.php3?id_article=141)

void CMyAppUi::BringToForeground()
{
 // Construct en empty TApaTask object
 // giving it a reference to the Window Server session
 TApaTask task(iEikonEnv->WsSession( ));
               
 // Initialise the object with the window group id of
 // our application (so that it represent our app)
 task.SetWgId(CEikonEnv::Static()->RootWin().Identifier());

 // Request window server to bring our application
 // to foreground
 task.BringToForeground();
}

下面的代码经我的测试是可行的

// Bring the application "theApp" to background
 TApaTaskList tasklist(iCoeEnv->WsSession());
 TApaTask     task(tasklist.FindApp(_L("theApp")));
 task.SendToBackground();  // or BringToForeground()

三、Summary

      演示了AppUi的HandleForgroundEventL ()方法和应用程序主动请求改变Foucs的方法