Java学习第一天

import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JTextField;
//调用
public class kc {//主函数
    javax.swing.JFrame jf = new javax.swing.JFrame();//创建窗体
    public static void main(String[] args) {
        kc lo = new kc();
        lo.showUI();//显示UI
    }
    public class ButListener implements ActionListener {
        private JTextField jt;
        public void setJt(JTextField jt) {
            this.jt = jt;
        }
        public void actionPerformed(ActionEvent e) {
            jt.setText("joyer520");
        }
    }//“打印”按钮的回应
    public class ButListener2 implements ActionListener {//“关闭”按钮的回应
        public void actionPerformed(ActionEvent e) {
            System.exit(0);
        }
    }
    public void showUI() {
        jf.setTitle("kc");
        jf.setSize(300, 400);
        jf.setLocationRelativeTo(null);
        jf.setLayout(null);
        jf.setResizable(false);
        jf.setUndecorated(true);//设置窗体

        javax.swing.JButton jbu = new javax.swing.JButton(" 打印");
        jbu.setBounds(30, 30, 70, 25);
        jbu.setBackground(Color.BLACK);
        jbu.setForeground(Color.white);
        jbu.setFocusPainted(false);
        jf.add(jbu);//设置按钮

        javax.swing.JButton jbu2 = new javax.swing.JButton("退出");
        jbu2.setBounds(30, 130, 70, 25);
        jbu2.setBackground(Color.BLACK);
        jbu2.setForeground(Color.white);
        jbu2.setFocusPainted(false);
        jf.add(jbu2);//设置按钮

        javax.swing.JTextField jtf = new javax.swing.JTextField();
        java.awt.Dimension dm = new java.awt.Dimension(280, 30);
        jtf.setPreferredSize(dm);
        jtf.setBounds(30, 150, 150, 25);
        jf.add(jtf);//设置文本框

        ButListener but = new ButListener();
        jbu.addActionListener(but);
        ButListener2 but2 = new ButListener2();
        jbu2.addActionListener(but2);//类似C++的信号槽
        but.setJt(jtf);//“打印”与文本框建立联系
        jf.setVisible(true);//可以显示
    }
}