java 使用布局在屏幕中央设置面板

Setting panel at center of screen by using layout

提问by stillStudent

I tried setting the position of child-panel at the center of parent-panel by using

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);

But it's getting added at the middle of horizontal screen but vertically at top.

但它被添加在水平屏幕的中间但垂直在顶部。

What do I need to do to add it at center of screen vertically and horizontally?

我需要做什么才能将它垂直和水平添加到屏幕中央？

回答by Michael Myers

If I understand correctly, you want an interface something like this:

如果我理解正确，你想要一个这样的界面：

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

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

...并且您没有其他组件添加到父面板。

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

如果是这种情况，我知道您有两个选择（基于这个问题，我显然已经回答了）：

1. Use a GridBagLayoutwith an empty GridBagConstraintsobject, like this:

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

2. Use a BoxLayout, like this:

   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()); 
   

1. 将 aGridBagLayout与空GridBagConstraints对象一起使用，如下所示：

   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());