import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class MyFrame extends JFrame{
public MyFrame(){
setSize(500,500);
setVisible(true);
Graphics g=this.getGraphics();
g.setColor(new Color(255,0,0));
g.drawString("hello",30,40);
g.fillRect(20,30,200,300);
g.fillArc(300,300,50,50,20,20);
addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0); //关闭窗口时退出
}
});
}
public static void main(String args[]){
new MyFrame();
}
}
各位帮忙看看,为什么这个程序运行的结果不固定呢,有时能显示出所画的图形,有时就显示不出来。
import java.awt.*;
import java.awt.event.*;
public class MyFrame extends JFrame{
public MyFrame(){
setSize(500,500);
setVisible(true);
Graphics g=this.getGraphics();
g.setColor(new Color(255,0,0));
g.drawString("hello",30,40);
g.fillRect(20,30,200,300);
g.fillArc(300,300,50,50,20,20);
addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0); //关闭窗口时退出
}
});
}
public static void main(String args[]){
new MyFrame();
}
}
各位帮忙看看,为什么这个程序运行的结果不固定呢,有时能显示出所画的图形,有时就显示不出来。
import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;import javax.swing.JFrame;
public class MyFramexxx extends JFrame{
public MyFramexxx(){
setSize(500,500);
setVisible(true);
this.doLayout();
}
@Override
public void paint(Graphics g) {
g.setColor(new Color(255,0,0));
g.drawString("hello",30,40);
g.fillRect(20,30,200,300);
g.fillArc(300,300,50,50,20,20);
addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0); //关闭窗口时退出
}
});
}
public static void main(String args[]){
new MyFramexxx();
}
}