swing容器继承重绘问题解决

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.

 

 

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