GUI編程-2

2.5.事件監聽

public class Test02 {
    public static void main(String[] args) {
        //按下按鈕,觸發事件
        //兩個按鈕可以實現同一個監聽

        Frame frame = new Frame();
        frame.setBackground(new Color(208, 162, 226));
        frame.setVisible(true);
        frame.setBounds(200,200,200,200);

        Button button1 = new Button("button1");
        button1.setActionCommand("button1按鈕點擊");

        //因爲addActionListener()需要一個ActionListener,所以我們需要構造一個ActionListener
        button1.addActionListener(new MyListen());

        Button button2 = new Button("button2");
        button2.setActionCommand("button2按鈕點擊");
        button2.addActionListener(new MyListen());

        frame.add(button1,BorderLayout.WEST);
        frame.add(button2,BorderLayout.EAST);
    }
}

class MyListen implements ActionListener{

    @Override
    public void actionPerformed(ActionEvent e) {
        System.out.println(e.getActionCommand());
    }
}

按下按鈕一和按鈕二時,會發生如下點擊事件:

2.6.輸入框TextField監聽

public class Test2 {
    public static void main(String[] args) {
        new MyFrame();
    }
}
class MyFrame extends Frame{
    public MyFrame(){
        setVisible(true);
        
        //frame的自適應大小函數
        pack();

        TextField field = new TextField();
        add(field);

        //設置替換編碼
        field.setEchoChar('*');

        //監聽這個文本框輸入的文字,按下enter,就會觸發這個輸入框的事件
        field.addActionListener(new MyActionListen());
    }
}
class MyActionListen implements ActionListener{

    @Override
    public void actionPerformed(ActionEvent e) {
        //獲得一些資源,返回一個對象
        TextField field = (TextField) e.getSource();
        //獲得輸入框的文字
        System.out.println(field.getText());
        //null,輸入框清零
        field.setText("");
    }
}

2.7.簡易計算器

//簡易計算器
public class TestCalc {
    public static void main(String[] args) {
        new Calculator().loadFrame();
    }
}

//計算器類
class Calculator extends Frame {

    //屬性
    TextField num1,num2,num3;

    //方法
    public void loadFrame(){
        num1 = new TextField(10);//字符數
        num2 = new TextField(10);
        num3 = new TextField(20);
        Button button = new Button("=");
        Label label = new Label("+");

        button.addActionListener(new MyCalculatorListener());

        //佈局
        setLayout(new FlowLayout());
        add(num1);
        add(label);
        add(num2);
        add(button);
        add(num3);
        pack();
        setVisible(true);
    }

    //監聽器類
    //內部類最大的好處,就是可以暢通無阻的訪問外部的屬性和方法
    private class MyCalculatorListener implements ActionListener{

        @Override
        public void actionPerformed(ActionEvent e) {
            //1.獲得加數和被加數
            //2.將這個值 +法運算後,放到第三個框
            //3.清除前兩個框
            int n1 = Integer.parseInt(num1.getText());
            int n2 = Integer.parseInt(num2.getText());
            num3.setText(""+(n1+n2));
            num1.setText("");
            num2.setText("");
        }
    }
}

2.8.畫筆

public class TestPaint {
    public static void main(String[] args) {
        new MyPaint().loadFrame();
    }
}
class MyPaint extends Frame{
    public void loadFrame(){
        setVisible(true);
        setBounds(400,400,400,400);
    }
    
    //畫筆
    @Override
    public void paint(Graphics g) {
        //畫筆,需要有顏色,畫筆可以畫畫
        g.setColor(new Color(125, 57, 99));
        g.drawRect(100,100,100,100);
        g.drawOval(200,200,50,50);
    }
}

2.9.鼠標監聽

//鼠標監聽事件
public class TestMouseListener {
    public static void main(String[] args) {
        new MyFrame("畫圖");
    }
}
class MyFrame extends Frame {
    
    //畫畫需要畫筆,需要監聽鼠標當前的位置,需要集合來存儲這個點
    private List points;

    public MyFrame(String title){
        super(title);
        
        //存鼠標點擊的點
        this.points = new ArrayList();
        
        setVisible(true);
        setBounds(400,400,400,400);
        
        //鼠標監聽器
        addMouseListener(new MouseListener());
    }
    @Override
    public void paint(Graphics g) {
        Iterator iterator = points.iterator();
        while (iterator.hasNext()){
            Point point = (Point) iterator.next();
            g.setColor(new Color(103, 188, 47));
            g.drawOval(point.x,point.y,5,5);
        }
    }
    class MouseListener extends MouseAdapter{
        @Override
        public void mousePressed(MouseEvent e) {
            MyFrame frame = (MyFrame) e.getSource();
            
            //這個點就是鼠標的點
            Point point = new Point(e.getX(), e.getY());
            points.add(point);
            
            //每次點擊鼠標都需要重新畫一遍
            frame.repaint();
        }
    }
}

2.10.窗口監聽

public class TestWindowListener {
    public static void main(String[] args) {
        new MyWindowListener();
    }
}

class MyWindowListener extends Frame{
    public MyWindowListener(){
        setVisible(true);
        setBackground(Color.BLUE);
        setBounds(300,300,300,300);
        addWindowListener(new WindowAdapter() {
            @Override//關閉窗口
            public void windowClosing(WindowEvent e) {
                System.out.println("窗口已關閉");
                System.exit(0);
            }

            @Override//激活窗口
            public void windowActivated(WindowEvent e) {
                setTitle("你快回來啊");
            }
        });
    }
}

2.11鍵盤監聽

public class TestKeyListener {
    public static void main(String[] args) {
        new KeyFrame();
    }
}

class KeyFrame extends Frame{
    public KeyFrame(){
        setVisible(true);
        setBounds(200,200,200,200);
        addKeyListener(new KeyAdapter() {
            @Override
            public void keyPressed(KeyEvent e) {
                
                //獲得鍵盤下的鍵是哪一個,當前的碼
                int keyCode = e.getKeyCode();
                
                //不需要記住這個數值,直接使用靜態屬性VK_XX
                if(keyCode == KeyEvent.VK_UP){
                    System.out.println("你按了上鍵");
                }
                //根據按下不同鍵,產生不同操作
            }
        });
    }
}