Question

当我更改JLabel的文本时，我对元素的整个GUI定位进行了更改。我是GUI的新手，因此我的知识仅限于它正在做的事情。

package GUI;

import javax.swing.*;

import com.tri_voltage.md.util.Tools;

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class GUI extends JFrame {
    /**
     * 
     */
    private static final long serialVersionUID = 1L;
    JButton b1 = new JButton("1"),b2=new JButton("2"),b3=new JButton("3"),b4=new JButton("4"),b5=new JButton("5"),b6=new JButton("6");
    JLabel l1= new JLabel("Label 1"),l2= new JLabel("Label 2"),l3=new JLabel("Label 3"),l4=new JLabel("Label 4"),l5=new JLabel("Label 5"),l6=new JLabel("Label 6");
    JPanel mainPane = new JPanel(), adminPane = new JPanel(), messagePane=new JPanel();
    JLayeredPane layeredPane = new JLayeredPane();
    private final int HEIGHT_0 = 0,HEIGHT_1=30,HEIGHT_2=60;
    private final int JBUTTON_WIDTH = 100,JBUTTON_HEIGHT = 25,JBUTTON_RIGHT = 305,JBUTTON_LEFT = 0;
    private final int JLABEL_WIDTH =50,JLABEL_HEIGHT =25,JLABEL_LEFT=0,JLABEL_RIGHT=150;
    private final int JPANEL_WIDTH = 1000,JPANEL_HEIGHT=1000;

    public GUI() {
        load();
    }
    public void load() {
        setTitle("Employee Console");
        setSize(JPANEL_WIDTH,JPANEL_HEIGHT);

        setVisible(true);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        mainPane = Tools.createPanel(0, 0, JPANEL_WIDTH, 700, new GridBagLayout());
        adminPane = Tools.createPanel(0, 700, JPANEL_WIDTH, 300, "Admin Console", new GridBagLayout());
        messagePane = Tools.createPanel(105, 0, 200, 90, new GridBagLayout());
        loadButtons();
        loadLabels();
        layeredPane.setPreferredSize(new Dimension(1000,1000));
        layeredPane.setSize(1000, 1000);
        add(layeredPane);
        //refresh();
    }
    public void loadButtons() {
        GridBagConstraints constraints = new GridBagConstraints();

        constraints.anchor = GridBagConstraints.CENTER;
        constraints.fill = GridBagConstraints.HORIZONTAL;
        constraints.weightx = 0.12;
        constraints.gridx = 2;
        constraints.ipady = 0;
        constraints.ipadx = 0;

        b1 = Tools.createButton(JBUTTON_LEFT, 0, JBUTTON_WIDTH, JBUTTON_HEIGHT, "Button 1", new ButtonListener(this));
        b2 = Tools.createButton(JBUTTON_LEFT, 30, JBUTTON_WIDTH, JBUTTON_HEIGHT, "Button 2", new ButtonListener(this));
        b3 = Tools.createButton(JBUTTON_LEFT, 60, JBUTTON_WIDTH, JBUTTON_HEIGHT, "Button 3", new ButtonListener(this));
        b4 = Tools.createButton(JBUTTON_RIGHT, 0, JBUTTON_WIDTH, JBUTTON_HEIGHT, "Button 4", new ButtonListener(this));
        b5 = Tools.createButton(JBUTTON_RIGHT, 30, JBUTTON_WIDTH, JBUTTON_HEIGHT, "Button 5", new ButtonListener(this));
        b6 = Tools.createButton(JBUTTON_RIGHT, 60, JBUTTON_WIDTH, JBUTTON_HEIGHT, "Button 6", new ButtonListener(this));
        mainPane.add(b1);
        mainPane.add(b2);
        mainPane.add(b3);
        mainPane.add(b4);
        mainPane.add(b5);
        mainPane.add(b6);
        layeredPane.add(mainPane,1);
    }

    public void loadLabels() {
        l1 = Tools.createLabel(JLABEL_LEFT,HEIGHT_0, JLABEL_WIDTH, JLABEL_HEIGHT, l1.getText());
        l2 = Tools.createLabel(JLABEL_LEFT,HEIGHT_1, JLABEL_WIDTH, JLABEL_HEIGHT, l2.getText());
        l3 = Tools.createLabel(JLABEL_LEFT,HEIGHT_2, JLABEL_WIDTH, JLABEL_HEIGHT, l3.getText());
        l4 = Tools.createLabel(JLABEL_RIGHT,HEIGHT_0, JLABEL_WIDTH, JLABEL_HEIGHT, l4.getText());
        l5 = Tools.createLabel(JLABEL_RIGHT,HEIGHT_1, JLABEL_WIDTH, JLABEL_HEIGHT, l5.getText());
        l6 = Tools.createLabel(JLABEL_RIGHT,HEIGHT_2, JLABEL_WIDTH, JLABEL_HEIGHT, l6.getText());
        messagePane.add(l1);
        messagePane.add(l2);
        messagePane.add(l3);
        messagePane.add(l4);
        messagePane.add(l5);
        messagePane.add(l6);
        layeredPane.add(messagePane,0);
    }
    public void refresh() {
        repaint();
    }
    public void actionPerformed(ActionEvent e) {
        switch (e.getActionCommand()) {

        }
    }

}

class ButtonListener implements ActionListener {
    private final GUI gui;
    private String screen = "main";


    ButtonListener(GUI gui) {
        this.gui = gui;
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        switch (e.getActionCommand()) {
            case "Button 1":
                JOptionPane.showMessageDialog(new JFrame(),"Button 1 has been pressed!");
                break;

            case "Button 2": 
                gui.l1.setText(null);
                break;

        }
    }
}

工具：

package com.tri_voltage.md.util;

import java.awt.Color;
import java.awt.Font;
import java.awt.LayoutManager;
import java.awt.Toolkit;
import java.awt.event.ActionListener;
import java.awt.event.KeyListener;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.LineNumberReader;

import javax.swing.BorderFactory;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JComboBox;
import javax.swing.JComponent;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.event.MenuListener;

import com.tri_voltage.md.util.MediaType;

public class Tools {

    private final static Font defaultFont = new Font("Verdana", Font.PLAIN, 15);

    private final static ImageIcon defaultImageIcon = null;//TODO: Find a suitable image icon

    public static ImageIcon loadMediaTypeImageIcon(String type) {
        return loadMediaTypeImageIcon(MediaType.valueOf(type));
    }

    public static ImageIcon loadMediaTypeImageIcon(MediaType type) {
        return loadImageIcon(type.getImagePath());
    }

    public static ImageIcon loadImageIcon(String path) {
        if (path.equalsIgnoreCase("NONE"))
            return defaultImageIcon;
        return new ImageIcon(Toolkit.getDefaultToolkit().createImage(ClassLoader.getSystemResource(path)));
    }

    public static String readLine(InputStream stream, long lineNumber) {
        try {
            BufferedReader reader = new BufferedReader(new InputStreamReader(stream));
            for (long l = 0; l < lineNumber; l ++)
                reader.readLine();
            String line = reader.readLine();
            return line;
        } catch (IOException e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Gets the last line number within the file (fileLocation) that is being called.
     * @param fileLocation
     * @return The last line number of the file. <b>(NOTE: Keep in mind that the first line number of a file is 0!)</b>
     * @throws IOException
     */
    public static int getLastLineNumber(String location) {
        try {
            @SuppressWarnings("resource")
            LineNumberReader lnr = new LineNumberReader(new FileReader(new File(location)));
            lnr.skip(9223372036854775807L);
            return lnr.getLineNumber();
        } catch (IOException e) {
            e.printStackTrace();
            return 0;
        }
    }

    public static JPanel createPanel(int x, int y, int width, int height, String title, LayoutManager layout, JComponent... components) {
        JPanel panel = createPanel(x, y, width, height, layout);
        if (title != null || title != "")
            panel.setBorder(BorderFactory.createTitledBorder(title));
        if (components != null)
            for (JComponent component : components)
                if (component != null)
                    panel.add(component);
        return panel;
    }

    public static JPanel createPanel(int x, int y, int width, int height, LayoutManager layout, JComponent... components) {
        JPanel panel = createPanel(x, y, width, height, layout);
        if (components != null)
            for (JComponent component : components)
                if (component != null)
                    panel.add(component);
        return panel;
    }

    public static JPanel createPanel(int x, int y, int width, int height, LayoutManager layout) {
        JPanel panel = new JPanel();
        panel.setLayout(layout);
        panel.setBounds(x, y, width, height);
        return panel;
    }

    public static JButton createButton(int x, int y, int width, int height, String title, ActionListener listener) {
        JButton button = new JButton();
        if (title == null || title == "")
            button.setText("Button");
        else
            button.setText(title);
        button.setBounds(x, y, width, height);
        if (listener != null)
            button.addActionListener(listener);
        return button;
    }

    public static JTextField createTextField(int x, int y, int width, int height, String actionCommand, KeyListener keyListener, ActionListener actionListener) {
        JTextField textField = new JTextField();
        textField.setBounds(x, y, width, height);
        if (keyListener != null)
            textField.addKeyListener(keyListener);
        if (actionListener != null)
            textField.addActionListener(actionListener);
        if (actionCommand != null)
            textField.setName(actionCommand);
        return textField;
    }

    public static JTextField createTextField(int x, int y, int width, int height, String actionCommand, KeyListener listener) {
        JTextField textField = new JTextField();
        textField.setBounds(x, y, width, height);
        if (listener != null)
            textField.addKeyListener(listener);
        if (actionCommand != null)
            textField.setName(actionCommand);
        return textField;
    }

    public static JCheckBox createCheckBox(int x, int y, int width, int height, String name, ActionListener listener) {
        JCheckBox checkBox = new JCheckBox(name);
        checkBox.setBounds(x, y, width, height);
        if (listener != null)
            checkBox.addActionListener(listener);
        return checkBox;
    }

    public static JComboBox<String> createComboBox(int x, int y, int width, int height, String actionCommand, String[] options, ActionListener listener) {
        JComboBox<String> comboBox = new JComboBox<String>(options);
        comboBox.setBounds(x, y, width, height);
        if (actionCommand != null)
            comboBox.setActionCommand(actionCommand);
        return comboBox;
    }

    public static JLabel createLabel(int x, int y, int width, int height, String title, Color background, Color foreground) {
        JLabel label = createLabel(x, y, width, height, title, background);
        label.setForeground(foreground);
        return label;
    }

    public static JLabel createLabel(int x, int y, int width, int height, String title, Color background) {
        JLabel label = createLabel(x, y, width, height, title);
        label.setBackground(background);
        return label;
    }

    public static JLabel createLabel(int x, int y, int width, int height, String title) {
        JLabel label = new JLabel();
        if (title != null || title != "")
            label.setText(title);
        label.setBounds(x, y, width, height);
        return label;
    }

    public static JMenu createMenu(String name, JMenuBar parent, MenuListener listener) {
        JMenu menu = new JMenu(name);
        menu.addMenuListener(listener);
        parent.add(menu);
        return menu;
    }

    public static JMenu createMenu(String name, JMenuBar parent) {
        return createMenu(name, parent, null);
    }

    public static JMenuItem createMenuItem(String name, JMenu parent, ActionListener listener) {
        JMenuItem item = new JMenuItem(name);
        item.addActionListener(listener);
        parent.add(item);
        return item;
    }

    /**
     * @return the defaultfont
     */
    public static Font getDefaultfont() {
        return defaultFont;
    }

}

以下是附图：按下按钮2之前：

按下按钮2后：

Answer 1

您应该使用布局等容器并向其添加元素。这可以确保元素是固定的。如果你没有使用任何容器，那么当你调整所有元素时，不会随之调整大小。这也是问题所在。当您的标签尺寸发生变化时，整个内容都会受到影响。

只需查看此链接即可了解有关学习布局的更多信息。

http://www.tutorialspoint.com/swing/swing_layouts.htm

当使用JLabel的setText（）时，Java，GUI会更改所有内容

1 个答案: