/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package newpackage;import java.awt.Graphics;
import javax.swing.JFrame;
import javax.swing.JPanel;/**
*
* @author Administrator
*/
public class Fuck extends JFrame { public Fuck(Test test) {
add(test);
} public static void main(String args[]) {
Test test = new Test();
Fuck fuck = new Fuck(test);
fuck.setVisible(true);
fuck.setSize(400, 800);
try {
Thread.sleep(3000);
} catch (Exception e) {
e.printStackTrace();
}
test.setxy(400, 400);
try {
Thread.sleep(2000);
} catch (Exception e) {
e.printStackTrace();
}
fuck.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}class Test extends JPanel { int x = 100;
int y = 200;
int p = 300;
int q = 700; protected void paintComponent(Graphics g) {
g.drawLine(x, y, p, q);
} public void setxy(int x1, int y1) {
this.x = x1;
this.y = y1;
repaint();
}
}为什么重画后原先的线没有被删除??
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package newpackage;import java.awt.Graphics;
import javax.swing.JFrame;
import javax.swing.JPanel;/**
*
* @author Administrator
*/
public class Fuck extends JFrame { public Fuck(Test test) {
add(test);
} public static void main(String args[]) {
Test test = new Test();
Fuck fuck = new Fuck(test);
fuck.setVisible(true);
fuck.setSize(400, 800);
try {
Thread.sleep(3000);
} catch (Exception e) {
e.printStackTrace();
}
test.setxy(400, 400);
try {
Thread.sleep(2000);
} catch (Exception e) {
e.printStackTrace();
}
fuck.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}class Test extends JPanel { int x = 100;
int y = 200;
int p = 300;
int q = 700; protected void paintComponent(Graphics g) {
g.drawLine(x, y, p, q);
} public void setxy(int x1, int y1) {
this.x = x1;
this.y = y1;
repaint();
}
}为什么重画后原先的线没有被删除??
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前清一下Graphics
test.getGraphics().clearRect(0, 0, 400, 800);