Question

我的这个 Java程序怎么改，才能使得按钮具有缩小图片的功能

import java.awt.BorderLayout;

import javax.swing.*;
public class lianxi13 extends JFrame{
JPanel n;
JLabel n1;
JLabel n2;
ImageIcon n3;
JButton n4;
public lianxi13(){
super("fds");
setSize(286,168);
this.setVisible(true);
n=new JPanel();
n.setLayout(new BorderLayout());
n3=new ImageIcon("D://8.jpg");
n1=new JLabel(n3);
n2=new JLabel("带图标的组件");
n.add(n1,BorderLayout.WEST);
n.add(n2,BorderLayout.EAST);
n4=new JButton("缩小");
n.add(n4);
this.add(n);

}
public static void main(String[] args) {
new lianxi13();

}

}

Answer 1

public lianxi13(){

super("fds");

setSize(286,168);

n=new JPanel();

    n.setLayout(new BorderLayout());

    n3=new ImageIcon("D://8.jpg");

 

    Image scaleImg=n3.getImage().getScaledInstance(50, 50, Image.SCALE_AREA_AVERAGING);

    ImageIcon scaleIcon=new ImageIcon(scaleImg);

    n1=new JLabel(scaleIcon);

    

    n2=new JLabel("带图标的组件");

    n.add(n1,BorderLayout.WEST);

    n.add(n2,BorderLayout.EAST);

    n4=new JButton("缩小");

    n.add(n4);

    this.add(n);

this.setVisible(true);

}

public static void main(String[] args) {

new lianxi13();

}

Answer 2

 n4.addActionListener(new ActionListener() {
		@Override
		public void actionPerformed(ActionEvent e) {
			try {
				BufferedImage bi = new BufferedImage((int)(n3.getIconWidth()*0.8),(int)(n3.getIconHeight()*0.8),BufferedImage.TYPE_3BYTE_BGR);
				bi.getGraphics().drawImage(n3.getImage(), 0, 0, (int)(n3.getIconWidth()*0.8), (int)(n3.getIconHeight()*0.8),null);
				bi.getGraphics().dispose();
				n3.setImage(bi);
				repaint();
			} catch (Exception e1) {
				e1.printStackTrace();
			}
			
		}
	});

把这个代码加上试试。加在n4=new JButton("缩小");的后面

Answer 3

你都没有设置响应时间么。