一个关于线程的简单问题（在线等）

[scarletg]

使用线程 ，将一个panel 的背景每200ms改变一次

[hoszone]

用一个timer

[mac1982129]

用不着线程吧

[yyjzsl]

关注，顶下

[amandag]

up

[rianting]

import javax.swing.JPanel;
import javax.swing.JFrame;
import java.awt.Container;
import java.awt.Color;

class Bg extends JFrame implements Runnable
{
private JPanel pan = new JPanel();
public Bg()
{
this.setTitle("demo");
this.setSize(500,300);
}
public void run()
{
try
{
for(int i = 0; i < 100; i ++)
{
if(i % 2== 0)
{
pan.setBackground(Color.red);
Container con = this.getContentPane();
con.add(pan);
}
else
{
pan.setBackground(Color.blue);
Container con = this.getContentPane();
con.add(pan);
}
Thread.sleep(2000);
}

}
catch(InterruptedException e)
{
e.printStackTrace();
}
}
}

public class demo
{
public static void main(String[] args)
{
Bg bb = new Bg();
Thread th = new Thread(bb);
th.start();
bb.show(true);

}
}

[amandag]

import java.awt.*;
import javax.swing.*;

public class Test extends JFrame{
public Test() {
this.getContentPane().add(new MyPanel());
this.setSize(200, 300);
this.show();
}

public static void main(String [] args){
new Test();
}
}

class MyPanel extends JPanel implements Runnable{
Thread thread;

public MyPanel(){
new Thread(this).start();
}

private static final Color[] colors = {
Color.BLACK, Color.BLUE, Color.CYAN,
Color.DARK_GRAY, Color.GRAY, Color.GREEN,
Color.LIGHT_GRAY, Color.MAGENTA, Color.ORANGE,
Color.PINK, Color.RED, Color.WHITE,Color.YELLOW
};
public void paint(Graphics g) {
super.paint(g);
int i = (int) Math.round((Math.random() * 12));
this.setBackground(colors[i]);

}

public void run(){
while(true){
try{
repaint();
Thread.sleep(200);
}
catch(InterruptedException e){
System.out.println(e.getMessage());
}
}
}
}

[success_dream]

大家都写的不错啊！楼主用上面的几个程序试下啊！

[nanazhu]

package exercise;
import java.awt.*;
import javax.swing.*;

public class threadexercise extends JFrame{
public threadexercise()
{
}

public static void main(String args[])
{
threadexercise tf = new threadexercise();
tf.setSize(200, 300);
tf.setVisible(true);
int i = 0;
try
{
while(true)
{

Color color = new Color(i);
tf.getContentPane().setBackground(color);
Thread.sleep(1500);
i += 50;
}
}
catch(InterruptedException e)
{
System.out.println("123");
}
}
}