使用GridBagConstraint.anchor = NORTH获取两个元素

Question

我想在GridBagLayout中将两个元素放在彼此的顶部，两个元素都应位于布局的顶部（第二个元素应从第一个元素的底部开始）。

此外，第二个元素将空间填充到底部。

gbc.anchor = GridBagConstraint.NORTH适用于第一个元素，但第二个元素不会粘在可用空间的顶部。 相反，它会粘在布局后半部分的顶部。

这是我的代码：

import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;

import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JPanel;


public class TestFrame extends JFrame{

    public TestFrame(){
        this.setDefaultCloseOperation(EXIT_ON_CLOSE);

        this.setLayout(new GridBagLayout());
        GridBagConstraints gbc = new GridBagConstraints();

        gbc.anchor = GridBagConstraints.NORTH;
        gbc.weighty = 1.0;

        JPanel one = new JPanel();
        one.setPreferredSize(new Dimension(200,200));
        one.setBorder(BorderFactory.createLineBorder(Color.BLACK));

        JPanel two = new JPanel();
        two.setPreferredSize(new Dimension(200,200));
        two.setBorder(BorderFactory.createLineBorder(Color.BLACK));

        this.add(one, gbc);

        gbc.gridy = 1;
        gbc.fill = GridBagConstraints.VERTICAL;

        this.add(two, gbc);

        this.pack();
        this.setVisible(true);
    }

    public static void main(String[] args){
        new TestFrame();
    }
}

Answer 1

我刚刚找到了解决方案： 如果我将第一个元素的wheighty设置为0.0而将第二个元素的weighty设置为1.0，则它会按计划运行。

import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;

import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JPanel;


public class TestFrame extends JFrame{

    public TestFrame(){
        this.setDefaultCloseOperation(EXIT_ON_CLOSE);

        this.setLayout(new GridBagLayout());
        GridBagConstraints gbc = new GridBagConstraints();

        gbc.anchor = GridBagConstraints.NORTH;
        gbc.weighty = 0.0;

        JPanel one = new JPanel();
        one.setPreferredSize(new Dimension(200,200));
        one.setBorder(BorderFactory.createLineBorder(Color.BLACK));

        JPanel two = new JPanel();
        two.setPreferredSize(new Dimension(200,200));
        two.setBorder(BorderFactory.createLineBorder(Color.BLACK));

        this.add(one, gbc);

        gbc.gridy = 1;
        gbc.weighty = 0.0;
        gbc.fill = GridBagConstraints.VERTICAL;

        this.add(two, gbc);

        this.pack();
        this.setVisible(true);
    }

    public static void main(String[] args){
        new TestFrame();
    }
}