java - 初学者 GUI 幻灯片代码无法正常工作(可能是循环或按钮问题，不确定)

Question

我正在创建一个图片幻灯片，其中有一个按钮可以切换到下一张图像，并且应该循环播放它们。

我尝试为我的循环切换到 case 语句和嵌套 boolean 语句。

/*
 *
 */


import java.util.Scanner;
import javax.swing.*;

import java.awt.Color;
import java.awt.event.*;

public class SlideShow implements ActionListener {

    JFrame frame;
    JPanel picture;
    JLabel label, picture1;
    JButton button;
    JPanel contentPane;
    int x = 0;




    public SlideShow() {
        /* Create and set up the frame */
        frame = new JFrame("SlideShow");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        /* Create a content pane with a BoxLayout and empty borders */
        contentPane = new JPanel();
        contentPane.setLayout(new BoxLayout(contentPane, BoxLayout.PAGE_AXIS));
        contentPane.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10));
        contentPane.setBackground(Color.white);

        /* Create a label that shows a die face */
        picture1 = new JLabel(new ImageIcon("attachment_142650738.jpg"));
        picture1.setAlignmentX(JLabel.CENTER_ALIGNMENT);
        picture1.setBorder(BorderFactory.createEmptyBorder(0, 0, 10, 0));
        contentPane.add(picture1);

        button = new JButton("Next photo");
        button.setAlignmentX(JButton.CENTER_ALIGNMENT);
        button.addActionListener(this);
        contentPane.add(button);

        /* Add content pane to frame */
        frame.setContentPane(contentPane);

        /* Size and then display the frame. */
        frame.pack();
        frame.setVisible(true);
    }








    //ActionPerformed//
    public void actionPerformed(ActionEvent event) {
        String[] array = {
            "attachment_142650738.jpg", // 0
            "attachment_142650739.jpg", // 1
            "attachment_142650741.jpg", // 2
            "attachment_142650742.jpg" // 3     
        };


        x += 0;
        if (x == 1) {
            picture1.setIcon(new ImageIcon("attachment_142650738.jpg"));
        } else if (x == 2) {
            picture1.setIcon(new ImageIcon("attachment_142650738.jpg"));
        } else if (x == 3) {
            picture1.setIcon(new ImageIcon("attachment_142650738.jpg"));
        } else if (x == 4) {
            picture1.setIcon(new ImageIcon("attachment_142650738.jpg"));
        } else if (x == 5) {
            x = 0;
            picture1.setIcon(new ImageIcon("attachment_142650738.jpg"));
        }


    }




    //GUI//
    private static void runGUI() {
        JFrame.setDefaultLookAndFeelDecorated(true);

        SlideShow ok = new SlideShow();


    }


    public static void main(String[] args) {
        /* Methods that create and show a GUI should be
           run from an event-dispatching thread */
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                runGUI();
            }
        });
    }
}

当前没有错误，但按钮没有结果。

Answer 1

您将 SlideShow 类的成员 x 初始化为零 (0) - 这是不必要的，因为无论如何它都是隐式初始化的。

在方法 actionPerformed 中，您有这行代码

x += 0;

您没有更改x的值。因此它保持为零，因此不会执行任何条件语句。