关于java.awt图形绘制

1.创建一个图形界面，需要使用frame窗口
2.窗口中可以添加Component组件，大部分的组件都已经实现了Component接口，所以可以直接添加。
3.可以在实现了Component接口的组件中添加ActionListener监听事件。
4.可以在Frame对象中添加WindowAdapter对象使Frame对象实现退出的功能
例4.
class Exit extends WindowAdapter {
    @Override
    public void windowClosing(WindowEvent e) {
        System.exit(0);
    }
}
Exit exit = new Exit();
frame.addWindowListener(exit);

package study02;

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

public class TestText {
    public static void main(String[] args) {
        new MyFrame();
    }
}

class MyFrame extends Frame{
    public MyFrame(){
        this.setBounds(500,500,200,200);
        TextField textField = new TextField();
        this.add(textField);
        MyAction myAction = new MyAction();
        textField.addActionListener(myAction);
//        textField.setEchoChar('*');
        this.add(textField);
        this.setVisible(true);
        Exit exit = new Exit();
        this.addWindowListener(exit);
    }
}


class MyAction implements ActionListener {

    @Override
    public void actionPerformed(ActionEvent e) {
        TextField field = (TextField) e.getSource();
        System.out.println(field.getText());
        field.setText("");
    }
}
class Exit extends WindowAdapter {
    @Override
    public void windowClosing(WindowEvent e) {
        System.exit(0);
    }
}