import javax.swing.*;
import java.awt.Color;
import java.awt.event.*;
public class OODemo implements ActionListener{
JButton button;
public static void main(String args[]){
OODemo demo=new OODemo();
demo.go();
}
public void go(){
JFrame frame=new JFrame();
button=new JButton("trust me");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//会在windows关闭是结束程序
frame.getContentPane().add(button);
frame.setSize(300,500);
frame.setVisible(true);
button.setSize(20, 300);//**实际运行这里怎么改参数button大小都不改变**
button.setBackground(Color.blue);
button.addActionListener(this);
}
@Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
button.setText("I've been clicked!");
}
}