Question

我正在尝试用Java OOP构建一个小程序，该程序将显示一个椭圆形，将其位置更改为鼠标单击坐标。但是，由于我是初学者，所以我不知道如何完成它。

有人知道我的程序出了什么问题吗？

public class OvalWindow {

 JFrame window;
 int windowWidth = 500;
 int windowHeight = 500;

 OvalPanel panel;

   public void run() {
      //Set a window
      window = new JFrame("Oval moving");
      window.setVisible(true);
      window.setSize(windowWidth, windowHeight);
      window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);    

      //Create a panel and add it to the window
      panel = new OvalPanel();
      window.setContentPane(panel);

      //Change the location on mouse input
      panel.addMouseListener(new OvalMouseClick(panel));


   }

  public static void main(String[] args) {
    OvalWindow oWndow = new OvalWindow();
    oWndow.run();
  }

}

文件：Oval.java 创建一个椭圆形的类

 public class Oval {

        private int diameter;
        private int x;
        private int y;
        private Color color;

        public Oval(int x, int y, int diameter, Color color) {
            this.x = x;
            this.y = y;
            this.diameter = diameter;
            this.color = color;
        }

        public int getX() {
            return x;
        }
        public int getY() {
            return y;
        }
        public int getDiameter() {
            return diameter;
        }
        public Color getColor() {
            return color;
        }

        /*
         * Draw the oval 
         */
        public void draw(Graphics g) {
            g.fillOval(x, y, diameter, diameter);
            g.setColor(color);

        }
}

文件：OvalPanel.java 此类将椭圆形对象添加到屏幕。此外，设置椭圆的初始位置

    public class OvalPanel extends JPanel{
     Oval oval;

     public void addOval(Oval oval) {
     oval = new Oval(100, 100, 50, Color.BLACK);
     this.repaint();

    }
    public void paintComponent(Graphics g){
        oval.draw(g);
    }


  }

文件：OvalMouseClick.java 此类在屏幕上与鼠标单击坐标相同的位置处添加了一个新的椭圆形。

    public class OvalMouseClick extends MouseAdapter{
        OvalPanel panel;

        public OvalMouseClick(OvalPanel panel) {
            this.panel = panel;
        }


        @Override
        public void mouseClicked(MouseEvent e) {
            panel.addOval(new Oval(e.getX(), e.getY(), 50, Color.BLUE));

        }

    }

Answer 1

编写一个自定义View root = inflater.inflate(R.layout.fragment_home, container, false); Button profile =(Button)root.findViewById(R.id.button1); profile.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { Toast.makeText(getApplication(),"Sürücüler",Toast.LENGTH_SHORT).show(); } }); //similarly for other buttons return root;方法，使您的paintComponent()实际上显示某些内容。如果您向其中添加了组件，它们将自动显示，但是您的OvalPanel类不是一个组件（在UI方面），因此您需要显式编写代码以显示它们。

Oval

我还建议您阅读https://docs.oracle.com/javase/tutorial/uiswing/上的Swing跟踪记录，因为您不能只是“猜测”事物的工作方式。摇摆很复杂，您需要了解它的作用。然后您将意识到@Override public void paintComponent(Graphics g) { for(Oval o : ovals) o.draw(g); }和draw(Graphics g)不仅仅是具有不同名称的类似方法。

Answer 2

万一有人在寻找答案。这是我的解决方案：

我已经修改了文件：OvalWindow.java

        public class OvalWindow {

            JFrame window;
            OvalPanel panel;

            int windowWidth = 500;
            int windowHeight = 500;

            /**
             * Run the program
             */
            public void run() {
                // Set a window
                window = new JFrame("Oval moving");
                window.setVisible(true);
                window.setSize(windowWidth, windowHeight);
                window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

                // Create a panel and add it to the window
                panel = new OvalPanel();
                window.add(panel, BorderLayout.CENTER);

                panel.addMouseListener(new MouseAdapter() {
                    public void mouseClicked(MouseEvent e) {
                        panel.moveToCoord(e);
                    }
                });

            }

            public static void main(String[] args) {
                OvalWindow oWndow = new OvalWindow();
                oWndow.run();
            }

        }

我还大大修改了文件：OvalPanel.java

        public class OvalPanel extends JPanel {
            Oval oval;
            int x = 50;
            int y = 10;
            int diameter = 50;
            Color color = Color.BLUE;

            public void moveToCoord(MouseEvent e) {
                x = e.getX() - diameter / 2;
                y = e.getY() - diameter / 2;
                repaint();

            }

            @Override
            public void paintComponent(Graphics g) {
                super.paintComponent(g);
                oval = new Oval(x, y, diameter, color);
                oval.draw(g);

            }

        }

在文件上：Oval.java只是一个小小的变化：

 public void draw(Graphics g) {
    g.setColor(color);
    g.fillOval(x, y, diameter, diameter);

}

文件：OvalMouseClick.java被删除。

Answer 3

让“ OvalMouseClick”类实现接口MouseListener。如果您想在鼠标移动时做点什么，只需让该类还实现“ MouseMotionListener”接口即可。对于MouseWheel，您可以使用“ MouseWheelListener”界面。

如何将椭圆形移动到mouseClick的坐标？

3 个答案: