带有刻度的JSlider问题

Question

我第一次尝试使用JSlider，并尝试咨询How to Use Sliders 来学习基础知识。 但是当我尝试让刻度看起来像这样时：

 sliderInterior = new JSlider(JSlider.HORIZONTAL,-100,100,0);
 sliderInterior.setMinorTickSpacing(5);
 sliderInterior.setMajorTickSpacing(10);
 sliderInterior.setPaintTicks(true);

蜱虫只是没有出现。有什么问题？

编辑 按要求做了SSCCE。问题依然存在，JSlider 根本没有滴答声。

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package Interface;

import javax.swing.JOptionPane;
import javax.swing.JSlider;

    public class JSliderTicks extends javax.swing.JDialog {

    public JSliderTicks(java.awt.Frame parent, boolean modal) {
        super(parent, modal);
        initComponents();

        slider = new JSlider(JSlider.HORIZONTAL,0,10,5);
        slider.setMinorTickSpacing(1);
        slider.setMajorTickSpacing(2);
        slider.setPaintTicks(true);

        JOptionPane.showMessageDialog(null, slider);

        setVisible(true);
    }


    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        slider = new javax.swing.JSlider();

        setDefaultCloseOperation(javax.swing.WindowConstants.DISPOSE_ON_CLOSE);

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGap(85, 85, 85)
                .addComponent(slider, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap(115, Short.MAX_VALUE))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGap(117, 117, 117)
                .addComponent(slider, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap(160, Short.MAX_VALUE))
        );

        pack();
    }// </editor-fold>                        

    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        /* Set the Nimbus look and feel */
        //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
        /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
         * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
         */
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(JSliderTicks.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(JSliderTicks.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(JSliderTicks.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(JSliderTicks.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>

        /* Create and display the dialog */
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                JSliderTicks dialog = new JSliderTicks(new javax.swing.JFrame(), true);
                dialog.addWindowListener(new java.awt.event.WindowAdapter() {
                    @Override
                    public void windowClosing(java.awt.event.WindowEvent e) {
                        System.exit(0);
                    }
                });
                dialog.setVisible(true);
            }
        });
    }
    // Variables declaration - do not modify                     
    private javax.swing.JSlider slider;
    // End of variables declaration                   
}

我只更改了构造函数，因为我使用的是 JDialog Form，其余的都是自动实现的。

我刚刚注意到，如果我使用 JOptionPane，JSlider 可以正常工作，但在 JDialog 中它保持不变。

Answer 1

它在这个 SSCCE 中工作得很好。

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

class SliderTicks {

    public static void main(String[] args) {
        Runnable r = new Runnable() {

            @Override
            public void run() {
                JSlider sliderInterior = new JSlider(JSlider.HORIZONTAL, -100, 100, 0);
                sliderInterior.setMinorTickSpacing(5);
                sliderInterior.setMajorTickSpacing(10);
                sliderInterior.setPaintTicks(true);

                JOptionPane.showMessageDialog(null, sliderInterior);
            }
        };
        // Swing GUIs should be created and updated on the EDT
        // http://docs.oracle.com/javase/tutorial/uiswing/concurrency
        SwingUtilities.invokeLater(r);
    }
}

Answer 2

发生的情况是您正在构造函数中创建一个new JSlider，而此时已经在initComponents 中创建并添加了一个。此外，JOptionPane 也搞砸了，因为一个组件只能添加到一个父容器中。我删除了 JOptionPane 并重新初始化了 JSlider 并且它可以工作。我还相应地设置了minimum、maximum 和value。

    initComponents();

    //slider = new JSlider(JSlider.HORIZONTAL,0,10,5);
    slider.setMinimum(0);
    slider.setMaximum(10);
    slider.setValue(5);
    slider.setMinorTickSpacing(1);
    slider.setMajorTickSpacing(2);
    slider.setPaintTicks(true);

    //JOptionPane.showMessageDialog(null, slider);

    //setVisible(true);                              <<---- already set visible