java - 使用布局将面板设置在屏幕中央

Question

我尝试通过使用将子面板的位置设置在父面板的中心

parent_panel.setLayout(new BorderLayout());
parent_panel.add(child_panel, BorderLayout.CENTER);

但是它被添加在水平屏幕的中间但垂直在顶部。

我需要做什么才能将它垂直和水平地添加到屏幕中央？

Answer 1

如果我没理解错的话，你想要一个类似这样的界面:

+-------- Parent panel --------+|                              ||                              ||    +--- Child panel ----+    ||    |                    |    ||    |                    |    ||    |                    |    ||    |                    |    ||    +--------------------+    ||                              ||                              |+------------------------------+

...and you have no other components being added to the parent panel.

If this is the case, you have two choices that I know of (based on this question, which I apparently answered):

1. Use a GridBagLayout with an empty GridBagConstraints object, like this:

   parent_panel.setLayout(new GridBagLayout());
   parent_panel.add(child_panel, new GridBagConstraints());
   

2. 使用 BoxLayout，像这样:

   parent_panel.setLayout(new BoxLayout(parent_panel, BoxLayout.PAGE_AXIS));
   Box horizontalBox = Box.createHorizontalBox(); 
   horizontalBox.add(Box.createHorizontalGlue()); 
   horizontalBox.add(child_panel); 
   horizontalBox.add(Box.createHorizontalGlue()); 
   Box verticalBox = Box.createVerticalBox(); 
   verticalBox.add(Box.createVerticalGlue()); 
   verticalBox.add(horizontalBox); // one inside the other
   verticalBox.add(Box.createVerticalGlue());