swing容器继承重绘问题解决

以JPanel为例,继承JPanel,想动态为器更换背景,这就涉及到重绘问题.一下是本人重写代码:

package ui;

import java.awt.Graphics;

import java.awt.Graphics2D;

import java.awt.Image;

import java.awt.Rectangle;

import java.awt.TexturePaint;

import java.awt.image.BufferedImage;

import javax.swing.ImageIcon;

import javax.swing.JPanel;

public class JJPanel extends JPanel {

private static final long serialVersionUID = 1L;

BufferedImage bufImg;

Graphics2D g2d;

private Image img;

private static String imgPath=" ";

public JJPanel(String imgPath) {

setImgPath(imgPath);

}

public void paintComponent(Graphics g) {

img=new ImageIcon(getImgPath()).getImage();

setOpaque(false);// 设置false以便于设置背景

// 启用图像缓存设置好图像。

bufImg = new BufferedImage(img.getWidth(null),

img.getHeight(null), BufferedImage.TYPE_3BYTE_BGR);

g2d = bufImg.createGraphics();

g2d.drawImage(img, 0, 0, null);

g2d.dispose();// 释放资源

// 准备矩形，用来创建一个纹理填充

Rectangle rectan = new Rectangle(0, 0, img.getWidth(null),

img.getHeight(null));

TexturePaint tu = new TexturePaint(bufImg, rectan);

// 用创建的纹理填充来填充整个面板

g2d = (Graphics2D) g;

g2d.setPaint(tu);

g2d.fillRect(0, 0, this.getWidth(), this.getHeight());

super.paintComponent(g);

}

public void repaint() {

img=new ImageIcon(getImgPath()).getImage();

super.repaint();

}

/**

* @return the imagePath

*/

public String getImgPath() {

return imgPath;

}

/**

* @param imagePath the imagePath to set

*/

public static void setImgPath(String imgPath) {

JJPanel.imgPath = imgPath;

}

}

简单的重写paintcomponent()方法发现动态修改imgPath,无法重绘组件,原因就在还要重写repaint()方法,并及时把修改好的imgPath传到repaint()中,这样方可动态重绘.