java - 从容器的实例中删除组件是否保留在内存中？

Question

我有一个容器，可以在几个屏幕大小的 Pane 之间切换其主要内容。我没有使用 CardLayout，而是使用 remove(previous);添加(当前)；验证();

在这个容器中，我有每个 Pane 的数据字段，它们在启动时被初始化，这样我就可以轻松地在它们之间切换引用。

我的问题:
如果移除之前的pane并添加新的/当前的pane，那么之前pane的实例对象占用的内存是否还在内存中？

因为我考虑过将前一个 Pane 设置为 null 并在将其添加到容器之前重新创建当前 Pane 以尝试降低内存使用量，但不确定它是否真的会产生任何影响。

谢谢。 :)

编辑:这实际上不是我的课，但它演示了我将如何切换 View :

public class ViewManager {

   public static final int VIEW_LOGIN = 0;
   public static final int VIEW_CALENDAR = 1;
   public static final int VIEW_HELP = 2;
   public static final int VIEW_SETTINGS = 3;
   public static final int VIEW_PREFERENCES = 4;
   public static final int VIEW_STATS = 5;

   private static LoginPane login = new LoginPane();
   private static CalendarView calendar = new CalendarView();
   private static HelpPane help = new HelpPane();
   private static SettingsPane accountSettings = new SettingsPane();
   private static PreferencesPane preferences = new PreferencesPane();
   private static StatsPane stats = new StatsPane();

   private static int previousView;

   private static Object [] views = {login, calendar, help, accountSettings, preferences, stats};

   // Without settings old views to null and re-creating incoming view request
   public static void switchTo(int currentView){
      if(currentView == previousView) return;

      MainFrame.getContent().remove(views[previousView]);
      MainFrame.getContent().add(views[currentView]);        
      MainFrame.getContent().validate();
   }

    // Settings to null and re-creating incoming view request
   public static void switchToNullify(int currentView){
      if(currentView == previousView) return;

      MainFrame.getContent().remove(views[previousView]);
      views[previousView] = null;

      if(currentView == VIEW_LOGIN)            views[VIEW_LOGIN] = new LoginPane();
      else if(currentView == VIEW_CALENDAR)    views[VIEW_CALENDAR] = new CalendarView();
      else if(currentView == VIEW_HELP)        views[VIEW_HELP] = new HelpPane();
      else if(currentView == VIEW_SETTINGS)    views[VIEW_ACCOUNT_SETTINGS] = new SettingsPane();
      else if(currentView == VIEW_PREFERENCES) views[VIEW_PREFERENCES] = new PreferencesPane();
      else if(currentView == VIEW_STATS)       views[VIEW_STATS] = new StatsPane();

      MainFrame.getContent().add(views[currentView]);
      MainFrame.getContent().validate();
   }
}

Answer 1

If you remove the previous pane and add the new / current one, does the memory taken up by the previous pane's instance object remain in memory?

是的，除非您删除对该对象的所有 引用。完成此操作后，它将有资格进行垃圾回收。

Because I considered setting the previous pane to null...

好主意!