Javase，

Javase，

重写paintComponent(Graphics g)方法

实现图片的显示

    import java.awt.Graphics;
    import java.awt.Image;

    import javax.swing.ImageIcon;
    import javax.swing.JPanel;

    public class PicturePreview extends JPanel{
    //重写绘制组件方法，实现图片的显示
        @override
        public void paintComponent(Graphics g){
        super.paintComponent(g);

        //指定当前图片路径
        String filename = "picture\\1.JPG";

        //通过图片路径获取到图片中图像
        ImageIcon icon = new ImageIcon(fielname);
        Image image = icon.getImage();

        //把图像绘制在预览区的面板中,
        //图像在当前对象的(20,20)位置上显示，像素为450*600
        g.drawImage(image, 20, 20, 450, 600, this);
    }
}