按钮b1不能出现,,把窗口最大化后,,在返回最小化时,又出现按钮了,请问是怎么回事
import java.awt.*;
import javax.swing.*;public class lcd extends JFrame{
private JButton b1 = new JButton("sdf");
public lcd(){
Container con = this.getContentPane();
con.setLayout(null);
b1.setBounds(0, 0, 20, 20);
con.add(b1);
}
public void paint(Graphics g){
g.setColor(Color.RED);
g.drawString("hello java", 0,105);
}
public static void main(String args[]){
lcd lc= new lcd();
lc.setSize(300,300);
lc.setVisible(true);
}}
import java.awt.*;
import javax.swing.*;public class lcd extends JFrame{
private JButton b1 = new JButton("sdf");
public lcd(){
Container con = this.getContentPane();
con.setLayout(null);
b1.setBounds(0, 0, 20, 20);
con.add(b1);
}
public void paint(Graphics g){
g.setColor(Color.RED);
g.drawString("hello java", 0,105);
}
public static void main(String args[]){
lcd lc= new lcd();
lc.setSize(300,300);
lc.setVisible(true);
}}
import java.awt.*;
import javax.swing.*;public class lcd extends JFrame{
private JButton b1 = new JButton("sdf");
public lcd(){
Container con = this.getContentPane();
con.setLayout(null);
b1.setBounds(0, 0, 20, 20);
con.add(b1);
}
public void paint(Graphics g){
super.paint(g);
g.setColor(Color.RED);
g.drawString("hello java", 0,105);
}
public static void main(String args[]){
lcd lc= new lcd();
lc.setSize(300,300);
lc.setVisible(true);
}}
你再重新編譯下~·