Question

我的JTabbedPane实现不了选项卡改变其对应的Jpanel的功能，高手帮帮改一下。谢谢！

/*
* 音乐共享平台主窗体
*/
package com.pb.devj.demo;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Image;

import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTabbedPane;

public class myJFrameM extends JFrame {
public JPanel mainJPanel;
public JPanel songJPanel;
public JPanel downloadJPanel;
public JPanel myMusicJPanel;
public JTabbedPane tab;
public myJFrameM(){
tab = new JTabbedPane(JTabbedPane.TOP);
tab.setOpaque(false);
tab.setTabLayoutPolicy(JTabbedPane.WRAP_TAB_LAYOUT);
setTitle("音乐共享平台");
final Image jtImage = new ImageIcon("D:/PB项目素材/参与人员使用素材./main.jpg").getImage();
setSize(new Dimension(jtImage.getWidth(null),jtImage.getHeight(null)));
//将背景图绘制在Panel面板中
JPanel jtPanel =new JPanel(){
public void paint(Graphics g){
g.drawImage(jtImage,0,0,null);
super.paint(g);
}
};
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);
add(jtPanel);
jtPanel.setOpaque(false);
jtPanel.setLayout(null);
jtPanel.add(tab);
tab.setBounds(0,40,946,460);

//够建Tap选项卡
tab.addTab("主窗口",mainJPanel);
tab.addTab("歌曲列表",songJPanel);
tab.addTab("下载列表",downloadJPanel);
tab.addTab("我的音乐",myMusicJPanel);
//添加窗体
// tab.add( mainJPanel,0);
//tab.add( songJPanel,1);
// tab.add( downloadJPanel,2);
// tab.add( myMusicJPanel,3);

mainJPanel=new JPanel();
mainJPanel.setSize(946,460 );
mainJPanel.setBackground(Color.white);
mainJPanel.setVisible(true);
mainJPanel.setOpaque(false);

songJPanel=new JPanel();
songJPanel.setSize(946,460 );
songJPanel.setBackground(Color.RED);
songJPanel.setVisible(true);
songJPanel.setOpaque(false);

downloadJPanel=new JPanel();
downloadJPanel.setSize(946,460 );
downloadJPanel.setBackground(Color.white);
downloadJPanel.setVisible(true);
downloadJPanel.setOpaque(false);

myMusicJPanel=new JPanel();
myMusicJPanel.setSize(946,460 );
myMusicJPanel.setBackground(Color.white);
myMusicJPanel.setVisible(true);
myMusicJPanel.setOpaque(false);

}

public static void main(String[] arg){
myJFrameM f1= new myJFrameM ();
}
}

Answer 1

// 设置透明后，底色无效！
// 首先创建Panel，把它new出来之后，再放到tabpane中。

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Image;

import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTabbedPane;

public class myJFrameM extends JFrame {
public JPanel mainJPanel;
public JPanel songJPanel;
public JPanel downloadJPanel;
public JPanel myMusicJPanel;
public JTabbedPane tab;

public myJFrameM() {
tab = new JTabbedPane(JTabbedPane.TOP);
tab.setOpaque(false);
tab.setTabLayoutPolicy(JTabbedPane.WRAP_TAB_LAYOUT);
setTitle("音乐共享平台");
final Image jtImage = new ImageIcon("D:/PB项目素材/参与人员使用素材./main.jpg")
.getImage();
setSize(new Dimension(jtImage.getWidth(null), jtImage.getHeight(null)));
// 将背景图绘制在Panel面板中
JPanel jtPanel = new JPanel() {
public void paint(Graphics g) {
g.drawImage(jtImage, 0, 0, null);
super.paint(g);
}
};
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);
add(jtPanel);
jtPanel.setOpaque(false);
jtPanel.setLayout(null);
jtPanel.add(tab);
tab.setBounds(0, 40, 946, 460);

//
// // 添加窗体
// tab.add( mainJPanel,0);
// tab.add( songJPanel,1);
// tab.add( downloadJPanel,2);
// tab.add( myMusicJPanel,3);

mainJPanel = new JPanel();
// mainJPanel.setSize(946, 460);
mainJPanel.setBackground(Color.white);
// mainJPanel.setVisible(true);
// mainJPanel.setOpaque(false);

songJPanel = new JPanel();
// songJPanel.setSize(946, 460);
songJPanel.setBackground(Color.RED);
// songJPanel.setVisible(true);
// songJPanel.setOpaque(false);

downloadJPanel = new JPanel();
// downloadJPanel.setSize(946, 460);
downloadJPanel.setBackground(Color.white);
// downloadJPanel.setVisible(true);
// downloadJPanel.setOpaque(false);

myMusicJPanel = new JPanel();
// myMusicJPanel.setSize(946, 460);
myMusicJPanel.setBackground(Color.white);
// myMusicJPanel.setVisible(true);
// myMusicJPanel.setOpaque(false);

// 够建Tap选项卡
tab.addTab("主窗口", mainJPanel);
tab.addTab("歌曲列表", songJPanel);
tab.addTab("下载列表", downloadJPanel);
tab.addTab("我的音乐", myMusicJPanel);

}

public static void main(String[] arg) {
myJFrameM f1 = new myJFrameM();
}
}