-1

我有一个controlPanel（BoxLayout）：

controlPanel.setLayout(new BoxLayout(controlPanel, BoxLayout.Y_AXIS));

现在我构建了两个FlowLayout并将它们添加到contolPanel面板中：

JPanel fromDatePanel = new JPanel(new FlowLayout());
JPanel untilDatePanel = new JPanel(new FlowLayout());

fromDatePanel.add(new JLabel("From - "));
fromDatePanel.add(new JButton("..."));
untilDatePanel.add(new JLabel("Until - "));
untilDatePanel.add(new JButton("..."));

controlPanel.add(fromDatePanel);
controlPanel.add(untilDatePanel);

我得到这个：

在此处输入图像描述

为什么它会在布局之间产生间隙？JButton例如，如果我插入一个，它可以正常工作（它插入它们时没有间隙）。

如何消除两者之间的差距FlowLayout？（所以它会像蓝色的差距）

4

3 回答 3

2

GridBagLayout您可以使用（并使用GridBagConstraintwith a ）实现垂直布局（垂直居中gridwidth=REMAINDER）：

import java.awt.FlowLayout;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;

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

public class TestGridBagLayout {

    protected void initUI() {
        JFrame frame = new JFrame();
        JPanel controlPanel = (JPanel) frame.getContentPane();
        controlPanel.setLayout(new GridBagLayout());
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.gridwidth = GridBagConstraints.REMAINDER;

        JPanel fromDatePanel = new JPanel(new FlowLayout());
        JPanel untilDatePanel = new JPanel(new FlowLayout());

        fromDatePanel.add(new JLabel("From - "));
        fromDatePanel.add(new JButton("..."));
        untilDatePanel.add(new JLabel("Until - "));
        untilDatePanel.add(new JButton("..."));

        controlPanel.add(fromDatePanel, gbc);
        controlPanel.add(untilDatePanel, gbc);
        frame.setSize(600, 600);
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                TestGridBagLayout testMultiplePanels = new TestGridBagLayout();
                testMultiplePanels.initUI();

            }
        });
    }

}

关于添加到 a之间的差异JButton，这是由于. 返回首选大小，而将返回由无限维度解释的首选大小。JPanelBoxLayoutgetMaximumSize()BoxLayoutJButtonJPanelnullBoxLayout

如果你想保留你的BoxLayout，你可以覆盖JPanel.getMaximumSize()并返回getPreferredSize()：

import java.awt.Dimension;
import java.awt.FlowLayout;

import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;

public class TestGridBagLayout {

    protected void initUI() {
        JFrame frame = new JFrame();
        JPanel controlPanel = (JPanel) frame.getContentPane();
        controlPanel.setLayout(new BoxLayout(controlPanel, BoxLayout.Y_AXIS));
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JPanel fromDatePanel = new JPanel(new FlowLayout()) {
            @Override
            public Dimension getMaximumSize() {
                return getPreferredSize();
            }
        };
        JPanel untilDatePanel = new JPanel(new FlowLayout()) {
            @Override
            public Dimension getMaximumSize() {
                return super.getMaximumSize();
            }
        };

        fromDatePanel.add(new JLabel("From - "));
        fromDatePanel.add(new JButton("..."));
        untilDatePanel.add(new JLabel("Until - "));
        untilDatePanel.add(new JButton("..."));

        controlPanel.add(fromDatePanel);
        controlPanel.add(untilDatePanel);
        frame.setSize(600, 600);
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                TestGridBagLayout testMultiplePanels = new TestGridBagLayout();
                testMultiplePanels.initUI();

            }
        });
    }

}
于 2013-06-06T11:37:05.640 回答
2

请参阅使用不可见的组件作为填充关于Box.createVerticalGlue()。

于 2013-06-06T10:30:16.330 回答
1

在此处输入图像描述

我用过BorderLayout，效果很好。

        JPanel controlPanel = new JPanel();
        //  controlPanel.setLayout(new BoxLayout(controlPanel, BoxLayout.Y_AXIS));
        controlPanel.setLayout(new BorderLayout());

        JPanel fromDatePanel = new JPanel(new FlowLayout());
        JPanel untilDatePanel = new JPanel(new FlowLayout());

        fromDatePanel.add(new JLabel("From - "));
        fromDatePanel.add(new JButton("..."));
        untilDatePanel.add(new JLabel("Until - "));
        untilDatePanel.add(new JButton("..."));

        controlPanel.add(fromDatePanel, BorderLayout.NORTH);
        controlPanel.add(untilDatePanel, BorderLayout.CENTER);

编辑-1：

您可以在每个面板内添加嵌套面板。

嵌套面板

        JPanel controlPanel = new JPanel();
        controlPanel.setLayout(new BoxLayout(controlPanel, BoxLayout.Y_AXIS));
        // controlPanel.setLayout(new BorderLayout());

        JPanel fromDatePanel = new JPanel(new FlowLayout());
        JPanel untilDatePanel = new JPanel(new FlowLayout());
        JPanel thirdPnl = new JPanel(new FlowLayout());
        JPanel fourthPnl = new JPanel(new FlowLayout());

        JPanel thrdForthPnl = new JPanel(new BorderLayout()); 

        fourthPnl.add(new JLabel("Fourth"));
        fourthPnl.add(new JButton("4.1"));

        thirdPnl.add(new JLabel("Third"));
        thirdPnl.add(new JButton("3.1"));

        thrdForthPnl.add(thirdPnl, BorderLayout.NORTH);
        thrdForthPnl.add(fourthPnl, BorderLayout.CENTER);

        fromDatePanel.add(new JLabel("From - "));
        fromDatePanel.add(new JButton("..."));
        untilDatePanel.add(new JLabel("Until - "));
        untilDatePanel.add(new JButton("..."));

        controlPanel.add(fromDatePanel, BorderLayout.NORTH);
        controlPanel.add(untilDatePanel, BorderLayout.CENTER);
        controlPanel.add(thrdForthPnl, BorderLayout.SOUTH);
于 2013-06-06T10:59:38.503 回答