Java Swing GridBagLayout – 添加没有空格的按钮

如何删除gridBagLayout引起的间距并使它们粘在一起？
这是我的代码只需添加3个按钮.
我读了这个问题,但没有完整的解决方案How to fix gap in GridBagLayout;
我只想将所有按钮放在JFrame的顶部.

import java.awt.BorderLayout;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class MyProblem {

    private JFrame frame = new JFrame();

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

    public MyProblem() {
        frame.setLayout(new GridBagLayout());
        GridBagConstraints gc = new GridBagConstraints();
        gc.weightx = 1;
        gc.weighty = 1;
        gc.gridx = 0;
        gc.gridy = 0;
        gc.fill = GridBagConstraints.HORIZONTAL;
        gc.anchor = GridBagConstraints.NORTH;
        for (int i = 0; i < 3; i++) {
            JPanel jPanel = new JPanel(new BorderLayout());
            jPanel.setSize(80, 80);
            jPanel.add(new JButton("Button " + i),BorderLayout.PAGE_START);
            frame.add(jPanel, gc);
            gc.gridy++;
        }

        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(500, 500);
        frame.setVisible(true);
    }

}

我的按钮如何：

我希望我的按钮看起来像：

解决方法:

布局会产生一列按钮,所以..

更改：

        gc.fill = GridBagConstraints.HORIZONTAL;

至：

        gc.fill = GridBagConstraints.BOTH;

编辑1

I want to keep buttons to the same height as described in picture and just putting them at the top.

使用组合布局将它们限制在顶部相当容易.在这种情况下,我们可能会将带有按钮的面板添加到带有BorderLayout的面板的PAGE_START中.边框布局的那一部分将拉伸子组件的宽度(我们的面板与GridLayout)来填充可用空间,但它将尊重其中任何内容的高度 – 为组件提供所需的垂直空间.

编辑2

这是一个实现上述想法的MCVE.外面板(带有青色边框)用于约束按钮面板的高度(带橙色边框).有关其工作原理的更多详细信息,请参阅源代码中的注释.

import java.awt.*;
import javax.swing.*;
import javax.swing.border.LineBorder;

public class MyProblem {

    private JFrame frame = new JFrame();

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

    public MyProblem() {
        frame.setLayout(new BorderLayout()); // actually the default

        // we will use this panel to constrain the panel with buttons
        JPanel ui = new JPanel(new BorderLayout());
        frame.add(ui);
        ui.setBorder(new LineBorder(Color.CYAN, 3));

        // the panel (with GridLayout) for the buttons
        JPanel toolPanel = new JPanel(new GridLayout(0,1,0,4)); // added some gap
        toolPanel.setBorder(new LineBorder(Color.ORANGE, 3));
        // toolPanel will appear at the top of the ui panel
        ui.add(toolPanel, BorderLayout.PAGE_START); 
        for (int i = 0; i < 3; i++) {
            toolPanel.add(new JButton("Button " + i));
        }

        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        //frame.setSize(500, 500); // instead..
        frame.pack(); // pack will make it as small as it can be.
        frame.setMinimumSize(frame.getSize()); // nice tweak..
        frame.setVisible(true);
    }
}

标签：gridbaglayout,java,swing,layout-manager
来源： https://codeday.me/bug/20190727/1558450.html