在另一个JPanel之上的JPanel

Question

I have been using JPanels for a while and now want to place a JPanel on top of another JPanel.

I have looked at using JLayer but I was wondering If there is a solution to just set the layer of the bottom and top, I don't want to set each components layer if possible.

Example

JPanel bottomPanel = new JPanel();      # Set as bottom panel
JPanel topPanel = new JPanel();         # Set as top panel
JPanel sidePanel = new JPanel();        # Don't have to set
JPanel anotherSidePanel = new JPanel(); # Don't have to set

If this isn't possible what is the best solution for this, Thanks.

Answer 1

You can have the main panel use a BorderLayout .

Then you can do something like:

mainPanel.add(leftSide, BorderLayout.LINE_START);
mainPanel.add(rightSide, BorderLayout.LINE_END);
JLayeredPane lp = new JLayeredPane();
mainPanel.add(lp, BorderLayout.CENTER);

Answer 2

It sounds like what you want is a layout manager. There are a few different ones that suit different needs. There's a link at the bottom of this post.

My personal favorite is GridLayout. So for what you want to do, you can do this:

JPanel panel = new JPanel();
panel.setLayout(new GridLayout(2, 1));
//the first number is the number of rows, the second is the number of columns

JPanel topPanel = new JPanel();
JPanel bottomPanel = new JPanel();
panel.add(topPanel);
panel.add(bottomPanel);

That will do what you want.

If you wanted to read more about them, here's a link: Oracle Docs on Layout Managers