技術標籤：# Java題解

圖片檢視軟體，支援6張圖片。通過點選不同的按鈕，可以檢視不同的圖片。

MyFrame:

package com.itheima;

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

public class MyFrame extends JFrame{
    JButton button1,button2,button3
            ,button4,button5,
 
button6;
    JLabel label;
    PictureListener pictureListener;

    public MyFrame() {
        init();
        setVisible(true);
        pack();
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
    void init(){
        setLayout(new FlowLayout());
        button1 = new JButton("圖片1"
 
);
        button1.setFont(new Font("微軟雅黑",Font.PLAIN,12));//設定按鈕字型和大小
        add(button1);
        button2 = new JButton("圖片2");
        button2.setFont(new Font("微軟雅黑",Font.PLAIN,12));
        add(button2);
        button3 = new JButton("圖片3");
        button3.
 
setFont(new Font("微軟雅黑",Font.PLAIN,12));
        add(button3);
        button4 = new JButton("圖片4");
        button4.setFont(new Font("微軟雅黑",Font.PLAIN,12));
        add(button4);
        button5 = new JButton("圖片5");
        button5.setFont(new Font("微軟雅黑",Font.PLAIN,12));
        add(button5);
        button6 = new JButton("圖片6");
        button6.setFont(new Font("微軟雅黑",Font.PLAIN,12));
        add(button6);
        label = new JLabel();
        label.setPreferredSize(new Dimension(180,150));//設定標籤大小
        add(label);
        pictureListener = new PictureListener();
        button1.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                ImageIcon icon = new ImageIcon("1.jpg");
                Image temp = icon.getImage().getScaledInstance(label.getWidth(),//將圖片大小縮放成與標籤同比例
                        label.getHeight(), icon.getImage().SCALE_DEFAULT);
                icon = new ImageIcon(temp);
                label.setIcon(icon);
            }
        });
        button2.addActionListener(pictureListener);
        button3.addActionListener(pictureListener);
        button4.addActionListener(pictureListener);
        button5.addActionListener(pictureListener);
        button6.addActionListener(pictureListener);


    }
    private class PictureListener implements ActionListener {
        @Override
        public void actionPerformed(ActionEvent e) {
            if(e.getSource() == button2){
                ImageIcon icon = new ImageIcon("2.jpg");
                Image temp = icon.getImage().getScaledInstance(label.getWidth(),
                        label.getHeight(), icon.getImage().SCALE_DEFAULT);
                icon = new ImageIcon(temp);
                label.setIcon(icon);
            }
            if(e.getSource() == button3){
                ImageIcon icon = new ImageIcon("3.jpg");
                Image temp = icon.getImage().getScaledInstance(label.getWidth(),
                        label.getHeight(), icon.getImage().SCALE_DEFAULT);
                icon = new ImageIcon(temp);
                label.setIcon(icon);
            }
            if(e.getSource() == button4){
                ImageIcon icon = new ImageIcon("4.jpg");
                Image temp = icon.getImage().getScaledInstance(label.getWidth(),
                        label.getHeight(), icon.getImage().SCALE_DEFAULT);
                icon = new ImageIcon(temp);
                label.setIcon(icon);
            }
            if(e.getSource() == button5){
                ImageIcon icon = new ImageIcon("5.jpg");
                Image temp = icon.getImage().getScaledInstance(label.getWidth(),
                        label.getHeight(), icon.getImage().SCALE_DEFAULT);
                icon = new ImageIcon(temp);
                label.setIcon(icon);
            }
            if(e.getSource() == button6){
                ImageIcon icon = new ImageIcon("6.jpg");
                Image temp = icon.getImage().getScaledInstance(label.getWidth(),
                        label.getHeight(), icon.getImage().SCALE_DEFAULT);
                icon = new ImageIcon(temp);
                label.setIcon(icon);
            }
        }
    }
}

button1的監聽器是用匿名內部類實現的。

Main:

package com.itheima;
public class Main {
    public static void main(String[] args) {
        MyFrame myFrame = new MyFrame();
        myFrame.setBounds(100,100,240,300);
        myFrame.setTitle("匿名內部類的簡單應用");
    }
}

注意： 圖片路徑是放在專案路徑下的。