一、事件监听
1、事件监听
当某件事发生时，做些什么；
2、按钮点击监听
代码演示：
package com.zibo.lession02;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class TestAction {
public static void main(String[] args) {
Frame frame = new Frame("TestAction");
Button btn = new Button("btn");
//因为addActionListener()需要ActionListener，所以我们写一个实现类
MyActionListener myActionListener = new MyActionListener();
btn.addActionListener(myActionListener);
frame.add(btn,BorderLayout.CENTER);
frame.setBounds(300,300,500,500);
frame.setVisible(true);
}
}
class MyActionListener implements ActionListener{
@Override
public void actionPerformed(ActionEvent e) {
System.out.println("AAA");
}
}
运行结果：
3、两个按钮共用一个监听事件
代码演示：
package com.zibo.lession02;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class TestAction2 {
public static void main(String[] args) {
Frame frame = new Frame("TestAction2");
Button start = new Button("start");
Button stop = new Button("stop");
//因为addActionListener()需要ActionListener，所以我们写一个实现类
MyActionListener2 myActionListener = new MyActionListener2();
start.addActionListener(myActionListener);
stop.addActionListener(myActionListener);
stop.setActionCommand("stop-go");
frame.add(start,BorderLayout.EAST);
frame.add(stop,BorderLayout.WEST);
frame.setBounds(300,300,500,500);
frame.setVisible(true);
}
}
class MyActionListener2 implements ActionListener{
@Override
public void actionPerformed(ActionEvent e) {
System.out.println("按钮被点击了，ActionCommand：" + e.getActionCommand());
}
}
运行结果：
二、输入框事件监听
代码演示：
package com.zibo.lession02;
import java.awt.*;
public class TestTest01 {
public static void main(String[] args) {
new MyFrame();
}
}
class MyFrame extends Frame{
public MyFrame(){
setBounds(300,300,500,500);
TextField textField = new TextField();
//密码输入
// textField.setEchoChar('*');
textField.addActionListener(e -> {
TextField field = (TextField)e.getSource();
String text = field.getText();
System.out.println(text);
});
add(textField);
setVisible(true);
}
}
运行结果：
三、简易计算器
代码演示：
package com.zibo.lession02;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class EasyCalculator {
public static void main(String[] args) {
new MyEasyCalculator();
}
}
class MyEasyCalculator extends Frame{
public MyEasyCalculator(){
setBounds(500,500,400,80);
setLayout(new FlowLayout());
TextField field1 = new TextField(10);//10为字符数
Label add = new Label("+");
TextField field2 = new TextField(10);
Label is = new Label("=");
TextField field3 = new TextField(10);
Button go = new Button("go");
go.addActionListener(e -> {
if(!"".equals(field1.getText()) && !"".equals(field2.getText())){
field3.setText(String.valueOf(Integer.parseInt(field1.getText()) + Integer.parseInt(field2.getText())));
}
});
add(field1);
add(add);
add(field2);
add(is);
add(field3);
add(go);
setVisible(true);
}
}
运行结果：
四、画笔paint
代码演示：
package com.zibo.lession02;
import java.awt.*;
public class TestPaint {
public static void main(String[] args) {
new MyPaint().loadFrame();
}
}
class MyPaint extends Frame {
public void loadFrame(){
setBounds(300,300,500,500);
setVisible(true);
}
//画笔
@Override
public void paint(Graphics g) {
//设置画笔颜色
g.setColor(Color.RED);
//画空心圆
// g.drawOval(50,50,100,100);
//画实心圆
g.fillOval(50,50,100,100);
//画矩形
g.fillRect(200,200,100,150);
}
}
运行结果：
五、鼠标监听事件
代码演示：
package com.zibo.lession03;
import java.awt.*;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
public class TestMouseListener {
public static void main(String[] args) {
new MyFrame("TestMouseListener");
}
}
class MyFrame extends Frame{
List<Point> pointList = new ArrayList<>();
public MyFrame(String title){
setTitle(title);
setBounds(300,300,500,500);
setVisible(true);
//鼠标监听事件
addMouseListener(new MouseAdapter() {
@Override
public void mouseClicked(MouseEvent e) {
super.mouseClicked(e);
MyFrame myFrame = (MyFrame) e.getSource();
myFrame.addPaint(new Point(e.getX(),e.getY()));
//重置画笔
myFrame.repaint();
}
});
}
private void addPaint(Point point){
pointList.add(point);
}
@Override
public void paint(Graphics g) {
super.paint(g);
for (Point point : pointList) {
g.setColor(Color.RED);
g.fillOval(point.x, point.y, 10, 10);
}
}
}
运行结果：
六、窗口监听
代码演示：
package com.zibo.lession03;
import java.awt.*;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
public class TestWindowFrameListener {
public static void main(String[] args) {
new WindowFrame("TestWindowFrameListener");
}
}
class WindowFrame extends Frame{
public WindowFrame(String title) throws HeadlessException {
setTitle(title);
setBounds(300,300,500,500);
setBackground(Color.CYAN);
setVisible(true);
addWindowListener(new WindowAdapter() {
//常用4个
@Override
public void windowOpened(WindowEvent e) {
super.windowOpened(e);
System.out.println("窗口打开");
}
@Override
public void windowClosing(WindowEvent e) {
super.windowClosing(e);
System.out.println("窗口关闭中（常用）");
setVisible(false);//隐藏
System.exit(0);//结束程序
}
@Override
public void windowClosed(WindowEvent e) {
super.windowClosing(e);
System.out.println("窗口关闭后");
}
@Override
public void windowActivated(WindowEvent e) {
super.windowActivated(e);
System.out.println("窗口激活（常用）");
}
});
}
}
运行结果：
七、键盘监听
代码演示：
package com.zibo.lession03;
import java.awt.*;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
public class TestKeyListener {
public static void main(String[] args) {
new KeyFrame("TestKeyListener");
}
}
class KeyFrame extends Frame{
public KeyFrame(String title){
setTitle(title);
setBounds(300,300,500,500);
setVisible(true);
addKeyListener(new KeyAdapter() {
@Override
public void keyPressed(KeyEvent e) {
super.keyPressed(e);
if(e.getKeyCode() == KeyEvent.VK_Q){
System.out.println("你按了Q键！");
System.out.println(e.getKeyCode());
}
}
});
}
}
运行结果：
