java - JSpinner 显示不正确

Question

过去一个月我一直在开发 GUI，我发现 JSpinner 无法正确显示。只出现边框，没有数字，没有箭头，看图:

我可以判断某个组件何时启用或未启用，但这不是问题所在。

入门类，其中 MAIN 方法是:

import java.awt.Component;

import javax.swing.JFrame;
import javax.swing.JPopupMenu;

public class Starter extends JFrame {

    public final int WIDTH = 205, HEIGHT = 280;

    private static final long serialVersionUID = 1L;

    public Starter() throws InterruptedException {
        super("Editor");
        setDefaultCloseOperation(DO_NOTHING_ON_CLOSE);
        setLocation(0, 0);
        setSize(WIDTH + 5, HEIGHT + 50);
        setVisible(true);
        setResizable(false);
        setLocation(80, 180);
        setDefaultCloseOperation(DISPOSE_ON_CLOSE);
        JPopupMenu.setDefaultLightWeightPopupEnabled(false);

        loadCaterogy(new EditorObjectProperties());
    }

    public void loadCaterogy(EditorCategoryTemplate category) {
        for (Component component : category.getCategoryComponents()) {
            add(component);
        }
        repaint();
    }

    public static void main(String[] args) {
        try {
            new Starter();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}

编辑器类别 - 所有组件都在其中:

import java.awt.Font;
import java.awt.TextArea;

import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JSpinner;
import javax.swing.SpinnerNumberModel;

public class EditorObjectProperties extends EditorCategoryTemplate {

    public JLabel xLabel;
    public JSpinner xSpinner;
    public JLabel yLabel;
    public JSpinner ySpinner;
    public JLabel angleLabel;
    public JSpinner angleSpinner;
    public JLabel widthLabel;
    public JSpinner widthSpinner;
    public JButton deleteButton;

    public JLabel textLabel;
    public TextArea textArea;

    public void addCategoryComponents() {
        xLabel = new JLabel("x:");
        xLabel.setFont(new Font("Tahoma", Font.PLAIN, 14));
        xLabel.setBounds(25, 15, 15, 14);
        add(xLabel);

        xSpinner = new JSpinner(new SpinnerNumberModel(0, 0, WIDTH, 1));
        xSpinner.setBounds(42, 12, 50, 20);
        xSpinner.setEnabled(false);
        add(xSpinner);

        yLabel = new JLabel("y:");
        yLabel.setFont(new Font("Tahoma", Font.PLAIN, 14));
        yLabel.setBounds(102, 12, 15, 20);
        add(yLabel);

        ySpinner = new JSpinner(new SpinnerNumberModel(0, 0, HEIGHT, 1));
        ySpinner.setBounds(117, 12, 50, 20);
        ySpinner.setEnabled(false);
        add(ySpinner);

        angleLabel = new JLabel("angle:");
        angleLabel.setFont(new Font("Tahoma", Font.PLAIN, 14));
        angleLabel.setBounds(25, 47, 50, 20);
        add(angleLabel);

        angleSpinner = new JSpinner(new SpinnerNumberModel(0, -5, 360, 5));
        angleSpinner.setBounds(72, 49, 95, 20);
        angleSpinner.setEnabled(false);
        add(angleSpinner);

        widthLabel = new JLabel("width:");
        widthLabel.setFont(new Font("Tahoma", Font.PLAIN, 14));
        widthLabel.setBounds(25, 87, 50, 20);
        add(widthLabel);

        widthSpinner = new JSpinner(new SpinnerNumberModel(10, 10, WIDTH, 10));
        widthSpinner.setBounds(72, 86, 95, 20);
        widthSpinner.setEnabled(false);
        add(widthSpinner);

        textLabel = new JLabel("text:");
        textLabel.setFont(new Font("Tahoma", Font.PLAIN, 14));
        textLabel.setBounds(25, 173, 50, 20);
        add(textLabel);

        textArea = new TextArea();
        textArea.setBounds(72, 127, 95, 112);
        textArea.setEnabled(false);
        add(textArea);

        deleteButton = new JButton("Delete Object");
        deleteButton.setBounds(10, 250, 174, 25);
        deleteButton.setEnabled(false);
        add(deleteButton);
        add(new JLabel());
    }
}

还有抽象类别模板，其中一些幕后方法是:

import java.awt.Component;
import java.util.ArrayList;

public abstract class EditorCategoryTemplate {

    public final int WIDTH = 205, HEIGHT = 280;

    public ArrayList<Component> components;

    public EditorCategoryTemplate() {
        this.components = new ArrayList<Component>();
        start();
    }

    public abstract void addCategoryComponents();

    public void add(Component component) {
        components.add(component);
    }

    public ArrayList<Component> getCategoryComponents() {
        return components;
    }

    private void start() {
        addCategoryComponents();
    }
}

Answer 1

您的问题与 Swing 线程无关，而与布局以及未正确使用它们有关，实际上您存在三个主要问题:

1. 您尝试将组件添加到容器(这里是 JFrame 的 contentPane)，就好像容器使用空布局一样，但实际上它没有，而是使用 BorderLayout 作为其默认布局。
2. 在组件添加到 GUI 之前，您过早地在 JFrame 上调用 setVisible(true)
3. 仅使用绝对定位这一事实就是一个主要问题。如果您希望组件在所有平台上正确定位和调整大小，Swing GUI 需要正确使用布局管理器。

请注意，这并不是说您的线程是正确的，事实并非如此，但是解决这个问题并不能解决您的 GUI 和布局问题，而这些问题并不是由此引起的。

因此，为了“快速修复”，您可以通过以下方式修复问题 1 和 2:

public Starter() throws InterruptedException {
    super("Editor");
    setDefaultCloseOperation(DO_NOTHING_ON_CLOSE);
    setLocation(0, 0);
    setSize(WIDTH + 5, HEIGHT + 50);

    // **** REMOVE ****
    // setVisible(true); 

    setResizable(false);
    setLocation(80, 180);
    setDefaultCloseOperation(DISPOSE_ON_CLOSE);
    JPopupMenu.setDefaultLightWeightPopupEnabled(false);

    // **** ADD ****
    getContentPane().setLayout(null);   

    loadCaterogy(new EditorObjectProperties());

    // **** ADD ****
    setVisible(true);  
}

为了获得更强大的修复，我会更多地使用布局管理器。例如，这可能是一个起点:

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

import javax.swing.*;

public class EditorEg extends JPanel {
    private static final int MAX_X = 205;
    private static final int MAX_Y = 280;
    private static final int TA_ROWS = 8;
    private static final int TA_COLS = 16;
    private JSpinner xSpinner = new JSpinner(new SpinnerNumberModel(0, 0, MAX_X, 1));
    private JSpinner ySpinner = new JSpinner(new SpinnerNumberModel(0, 0, MAX_Y, 1));
    private JSpinner angleSpinner = new JSpinner(new SpinnerNumberModel(0, -5, 360, 5));
    private JSpinner widthSpinner = new JSpinner(new SpinnerNumberModel(10, 10, MAX_X, 10));
    private JTextArea textArea = new JTextArea(TA_ROWS, TA_COLS);
    private JButton deleteButton = new JButton("Delete");

    public EditorEg() {
        JPanel xyPanel = new JPanel(new GridBagLayout());
        int gap = 2;
        Insets insets = new Insets(gap, gap, gap, gap);
        GridBagConstraints gbc = new GridBagConstraints(0, 0, 1, 1, 1.0, 1.0,
                GridBagConstraints.BASELINE, GridBagConstraints.HORIZONTAL, insets, 0, 0);
        gbc.weightx = 0.2;
        xyPanel.add(new JLabel("x:"), gbc);
        gbc.gridx++;
        gbc.weightx = 1.0;
        xyPanel.add(xSpinner, gbc);
        gbc.gridx++;
        gbc.weightx = 0.2;
        xyPanel.add(new JLabel("y:"), gbc);
        gbc.gridx++;
        gbc.weightx = 1.0;
        xyPanel.add(ySpinner, gbc);

        JPanel angleWidthPanel = new JPanel(new GridBagLayout());
        gap = 3;
        insets = new Insets(gap, gap, gap, gap);
        gbc = new GridBagConstraints(0, 0, 1, 1, 1.0, 1.0,
                GridBagConstraints.BASELINE, GridBagConstraints.HORIZONTAL, insets, 0, 0);
        angleWidthPanel.add(new JLabel("angle:"), gbc);
        gbc.gridx++;
        angleWidthPanel.add(angleSpinner, gbc);
        gbc.gridx--;
        gbc.gridy++;
        angleWidthPanel.add(new JLabel("width:"), gbc);
        gbc.gridx++;
        angleWidthPanel.add(widthSpinner, gbc);

        JScrollPane scrollPane = new JScrollPane(textArea);
        scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
        scrollPane.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);

        JPanel scrollWrapper = new JPanel(new BorderLayout());
        scrollWrapper.setBorder(BorderFactory.createTitledBorder("Text"));
        scrollWrapper.add(scrollPane);

        setLayout(new GridBagLayout());
        gap = 4;
        setBorder(BorderFactory.createEmptyBorder(gap, gap, gap, gap));
        insets = new Insets(gap, gap, gap, gap);

        gbc = new GridBagConstraints(0, 0, 1, 1, 1.0, 1.0,
                GridBagConstraints.BASELINE, GridBagConstraints.HORIZONTAL, insets, 0, 0);
        add(xyPanel, gbc);
        gbc.gridy++;
        add(angleWidthPanel, gbc);
        gbc.gridy++;
        add(scrollWrapper, gbc);
        gbc.gridy++;
        add(deleteButton, gbc);
    }

    private static void createAndShowGui() {
        EditorEg mainPanel = new EditorEg();

        JFrame frame = new JFrame("Editor");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().add(mainPanel);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> createAndShowGui());
    }
}