Question

我有JPanel默认使用FlowLayout经理。我喜欢文档样式FlowLayout的优点，我在其中使用自动换行添加一个组件，但希望组件强制选择新行。

我读过如果我使用BoxLayout我可以插入一种component return key并强制组件在新行上开始。我需要有关我的决定的指导，哪种方法更好。

我在一行上有一个JLabel和JTextField，并希望将JTextArea包裹在JScrollPane下面。

Answer 1

使用FlowLayout 和 BorderLayout的组合。嵌套布局以获得理想的结果是个好主意。
JLabel和JTextField将与JPanel

FlowLayout

然后另一个JPanel BorderLayout将NORTH位置放在JTextArea位置，JScrollPane CENTER位于JPanel topPanel = new JPanel(); JLabel label = new JLabel("Text Field Label"); JTextField jtf = new JTextField(20); topPanel.add(label); topPanel.add(jtf); JPanel bothPanel = new JPanel(new BorderLayout()); JTextArea jta = new JTextArea(20, 40); bothPanel.add(topPanel, BorderLayout.NORTH); bothPanel.add(new JScrollPane(jta)); 1}}位置。

import java.awt.BorderLayout;
import java.awt.Color;

import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class FlowBorderDemo {

    public FlowBorderDemo() {
        JPanel topPanel = new JPanel();
        JLabel label = new JLabel("Text Field Label");
        label.setForeground(Color.white);
        JTextField jtf = new JTextField(20);
        topPanel.add(label);
        topPanel.add(jtf);
        topPanel.setBackground(Color.black);


        JPanel bothPanel = new JPanel(new BorderLayout());
        JTextArea jta = new JTextArea(20, 40);
        JScrollPane scrollPane = new JScrollPane(jta);
        scrollPane.setBorder(BorderFactory.createMatteBorder(3, 0, 0, 0, Color.GRAY));
        bothPanel.add(topPanel, BorderLayout.NORTH);
        bothPanel.add(scrollPane);
        bothPanel.setBorder(BorderFactory.createMatteBorder(3, 8, 3, 8, Color.GRAY));

        JLabel copyLabel = new JLabel("<html>&copy;2014 peeskillet</html>");
        copyLabel.setBackground(Color.LIGHT_GRAY);
        copyLabel.setHorizontalAlignment(JLabel.CENTER);
        bothPanel.add(copyLabel, BorderLayout.PAGE_END);


        JFrame frame = new JFrame();
        frame.add(bothPanel);
        frame.pack();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setLocationByPlatform(true);
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager
                            .getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException
                        | IllegalAccessException
                        | UnsupportedLookAndFeelException ex) {
                    ex.printStackTrace();
                }

                new FlowBorderDemo();
            }
        });
    }
}

查看Laying Out Components Within a Container

enter image description here

{{1}}

JPanel FlowLayout Force Component Wrap

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