我写了一个程序，想实现按oval按钮时，绘制圆形，按rectangle时，绘制矩形。
所以我写了两个JPanel的子类oval类和rectangle类。然后在JFrame中 想通过点击
不同按钮实现不同jpanel类的调用，该如何实现？
jframe子类
public class DrawShapeByMouse extends JFrame {
//add two buttons
private JButton button1 = new JButton("Oval");
private JButton button2 = new JButton("Rectangle");
private JPanel ShapeJpanel = new DrawOval();
//Constructors
public DrawShapeByMouse() {
this.add(ShapeJpanel,BorderLayout.CENTER);
add(button1,BorderLayout.SOUTH);
add(button2,BorderLayout.NORTH);
//给按键注册监听器
button1.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent arg0) {
ShapeJpanel = new DrawOval();
}
});
button2.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent arg0) {
ShapeJpanel = new DrawRectangle();
System.out.println("你好世界！");
}
});
}
public static void main(String[] args) {
DrawShapeByMouse frame = new DrawShapeByMouse();
frame.setTitle("DrawOvalByMouse");
frame.setSize(400,400);
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
}
oval类
class DrawOval extends JPanel {
private final Color[] color = {Color.red,Color.YELLOW,Color.GREEN,Color.ORANGE}; //填充颜色
private int xCoord = 0;//
private int yCoord = 0;//圆心坐标
private final int radius = 30; //半径
private int num = 0; //用来控制颜色
//Constructors
public DrawOval() {
//鼠标点击事件注册监听器并且实现接口
this.addMouseListener(new MouseAdapter() {
public void mousePressed(MouseEvent e) {
xCoord = e.getX();
yCoord = e.getY();
num = (int)(Math.random()*color.length);
repaint();
}
});
this.addMouseMotionListener(new MouseMotionAdapter() {
public void mouseDragged(MouseEvent e) {
xCoord = e.getX();
yCoord = e.getY();
repaint();
}
});
}
//绘制面板
protected void paintComponent(Graphics g) {
//super.paintComponent(g);
g.setColor(color[num]);
g.fillOval(xCoord-radius, yCoord-radius,radius,radius);
}
}
rectangle同oval类；
