Swing的组件图标

以图片做图标的方法

package Swing;

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

public class ImageIconDemo extends JFrame{
    
    public static void main(String[] args) {
    
        new ImageIconDemo();
    }
//以图片做图标
    public ImageIconDemo() {
    
        //创造一个名为ImageIcon的标签
        JLabel label = new JLabel("ImageIcon");
        //获取图片的地址
        URL url = ImageIconDemo.class.getResource("fj.jpg");
        //将图片属性转到imageIcon上
        ImageIcon imageIcon = new ImageIcon(url);
        //将图片设置在标签上
        label.setIcon(imageIcon);
        //设置图标居中
       label.setHorizontalAlignment(SwingConstants.CENTER);
       //创造一个容器并向容器中添加面板
       Container container=getContentPane();
       //将标签添加到容器中
       container.add(label);

      setVisible(true);
      setBounds(100,100,200,200);
      setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
    }
}

以画笔绘制的图形做图标

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

//图标，需要实现类，Frame 继承
public class IconDemo extends JFrame implements Icon {
    
    private int width;
    private int height;

    public static void main(String[] args) {
    
//两个调用方法都可
      // IconDemo iconDemo = new IconDemo(15,15);
       // iconDemo.init();
        new IconDemo().init();
    }

    public IconDemo() throws HeadlessException {
    }

    public IconDemo(int width, int height) {
    
        this.width = width;
        this.height = height;
    }

    public void init(){
    
        IconDemo iconDemo = new IconDemo(15, 15);
        //图标可以放在标签上也可以放在按钮上
        JLabel label = new JLabel("iconTest", iconDemo, SwingConstants.CENTER);
        Container container = getContentPane();
        container.add(label);

        setBounds(100,200,500,500);
        this.setVisible(true);
   this.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
    }

    @Override
    public void paintIcon(Component c, Graphics g, int x, int y) {
    
        g.fillOval(x,y,width,height);
    }

    @Override
    public int getIconWidth() {
    
        return this.width;
    }

    @Override
    public int getIconHeight() {
    
        return this.height;
    }
}