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我正在做一个程序，其中包含在一个数组中的 8 个形状，当您单击鼠标时将显示这些形状。我是 Java 新手，对事件处理程序和侦听器不太熟悉。

我试图使形状出现在框架内单击鼠标的位置，但我遇到了麻烦，因为每个形状的构造函数都使用 2 Points 作为其参数。

这是代码中的一个示例：

import MyLibs.Circle;
import MyLibs.Rectangle;
import MyLibs.Shape;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Point;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.Random;

public class DrawInScreenOnClickTest extends javax.swing.JFrame {

    private Image dbImage;

    Shape[] sh = new Shape[] {
        new Circle(new Point(50, 60), new Point(130, 180)),
            new Rectangle(new Point(50, 200), new Point(150, 350)),
            new Circle(new Point(200, 300), new Point(350, 350)),
            new Rectangle(new Point(100, 100), new Point(250, 250)),
            new Circle(new Point(150, 150), new Point(300, 300)),
            new Circle(new Point(200, 200), new Point(450, 500)),
            new Rectangle(new Point(300, 300), new Point(550, 550)),
            new Circle(new Point(150, 150), new Point(320, 320))
    };

    Color[] colors = new Color[] {
        Color.cyan, Color.green, Color.red, Color.blue, Color.magenta, Color.orange
    };

    Random random = new Random();
    int i = 0;
    Shape shape;
    boolean first = true;


    public DrawInScreenOnClickTest() {
        initComponents();
    }


    private void formMouseClicked(java.awt.event.MouseEvent evt) {
        repaint();
    }


    public class Mouse extends MouseAdapter {
        @Override
        public void mousePressed(MouseEvent e) {
            int x = e.getX();
            int y = e.getY();
        }
    }

    public void paint(Graphics g) {

        if (first == true) {
            first = false;
        } else {
            int shapeColor = random.nextInt(6);

            Shape shape = sh[i]; //calls shapes array
            shape.setColor(colors[shapeColor]); //call colors array random
            shape.drawShape(g); //display shape
            if (i == 4) {
                i = 0;
            } else
                i++;
        }
    }


    public static void main(String args[]) {
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new DrawInScreenOnClickTest().setVisible(true);
            }
        });
    }
}
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1 回答 1

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这是一个使用随机长度和宽度交替绘制形状（矩形和圆形）的示例。

此示例使用paintComponent(...)方法在屏幕上绘制形状。

JFrame除非你改变它的行为，否则你不应该扩展它，而是构建你的 UI 来使用JPanel更灵活的 s 并允许你使用paintComponent.

我使用了ShapeAPI 而不是自定义Shape类（您正在使用它并且您没有发布它的代码）。

我没有包括随机颜色，因为这取决于 OP 来编写它，这只是一个关于如何在鼠标单击时绘制组件的示例。

import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.Shape;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.geom.Ellipse2D;
import java.util.ArrayList;
import java.util.List;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;

public class DrawInScreenOnClickTest {
    private JFrame frame;
    private DrawingPane pane;
    private List<Shape> shapes;
    
    public static void main(String[] args) {
        SwingUtilities.invokeLater(new DrawInScreenOnClickTest()::createAndShowGUI);
    }
    
    private void createAndShowGUI() {
        frame = new JFrame(getClass().getSimpleName());
        
        shapes = new ArrayList<Shape>();
        shapes.add(new Ellipse2D.Double(50, 50, 50, 50));
        shapes.add(new Rectangle.Double(50, 200, 50, 100));
        shapes.add(new Ellipse2D.Double(150, 200, 150, 150));
        
        pane = new DrawingPane();
        
        pane.addMouseListener(new MouseListen());
        
        frame.add(pane);
        frame.pack();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
    }
    
    @SuppressWarnings("serial")
    class DrawingPane extends JPanel {
        public void addNewShape(Shape s) {
            
        }
        
        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            Graphics2D g2d = (Graphics2D) g;
            for (Shape s : shapes) {
                g2d.draw(s);
            }
        }
        
        @Override
        public Dimension getPreferredSize() {
            return new Dimension(500, 500);
        }
    }

    class MouseListen extends MouseAdapter {
        int counter = 0;
        
        @Override
        public void mouseClicked(MouseEvent e) {
            super.mouseClicked(e);
            counter++;
            
            if (counter % 2 == 0) {
                shapes.add(new Rectangle.Double(e.getX(), e.getY(), Math.random() * 50, Math.random() * 50));
            } else {
                shapes.add(new Ellipse2D.Double(e.getX(), e.getY(), Math.random() * 50, Math.random() * 50));
            }
            pane.repaint();
        }
    }
}

在此处输入图像描述

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于 2020-07-06T20:02:37.330 回答