JavaSwing学习笔记（二）

一：JLabel

新建MyIcon类实现Icon接口，再用此类实例化对象绘画一个圆，添加到JLabel中

package n1;

import java.awt.Color;
import java.awt.Component;
import java.awt.Container;
import java.awt.Graphics;

import javax.swing.Icon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingConstants;
import javax.swing.WindowConstants;

public class MyICon implements Icon{

    private int width;
    private int height;
    
    public MyICon(int width,int height){
        
        this.width=width;
        this.height=height;
    }
    public void paintIcon(Component c, Graphics g, int x, int y) {

        g.fillOval(x, y, width, height);
        //用Graphics对象来填充椭圆
    }

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

    @Override
    public int getIconHeight() {
        
        return this.height;
    }
    
    public static void main(String[] args) {
        
        MyICon icon=new MyICon(15, 15);
        JLabel label=new JLabel("你好",icon,SwingConstants.CENTER);
        JFrame jf=new JFrame("窗口");
        Container container=jf.getContentPane();
        container.setBackground(Color.white);
        container.add(label);
        jf.setVisible(true);
        jf.setSize(300, 200);
        jf.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
    }
}

运行结果：

image.png

参考资料：

• Java从入门到精通