使用 Java swing GUI 的形状计算器

Question

我创建了一个不是 GUI 的形状计算器，它可以根据所选形状很好地计算面积和体积，我正在尝试为同一程序创建一个 GUI 我运行遇到问题时它涉及根据用户输入显示形状和结果。我有 GUI 的布局，但使用 ActionPerformed 我无法弄清楚如何获取输入并调用形状 class 来进行计算而不是显示结果。

我已经修复了我的一些错误，并将其添加到运行但是它给出了输入数字值的错误消息并且无法计算 0.0 以外的区域。

import javax.swing.*;
import java.awt.*;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.ButtonGroup;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.JLabel;
import javax.swing.JRadioButton;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;


public class ControlPane extends JPanel implements ActionListener{


    // create buttons
    private JRadioButton circle;
    private JRadioButton square;
    private JRadioButton rectangle;
    private JRadioButton triangle;
    private JRadioButton sphere;
    private JRadioButton cube;
    private JRadioButton cylinder;
    private JRadioButton cone;
    private JRadioButton torus;
    private DrawPane drawPane;

    public ControlPane() {


        ButtonGroup bg1 = new ButtonGroup();
        circle = new JRadioButton("Circle");
        square = new JRadioButton("Square");
        rectangle = new JRadioButton("Rectangle");
        triangle = new JRadioButton("Triangle");

        sphere = new JRadioButton("Sphere");
        cube = new JRadioButton("Cube");
        cylinder = new JRadioButton("Cylinder");
        cone = new JRadioButton("Cone");
        torus = new JRadioButton("Torus");

        bg1.add(circle);
        bg1.add(square);
        bg1.add(rectangle);
        bg1.add(triangle);

        bg1.add(sphere);
        bg1.add(cube);
        bg1.add(cylinder);
        bg1.add(cone);
        bg1.add(torus);

        GridBagConstraints gbc = new GridBagConstraints();
        gbc.gridwidth = GridBagConstraints.REMAINDER;
        gbc.weightx = 1;

        JPanel shape = new JPanel();
        shape.add(circle);
        shape.add(square);
        shape.add(rectangle);
        shape.add(triangle);
        shape.add(sphere);
        shape.add(cube);
        shape.add(cylinder);
        shape.add(cone);
        shape.add(torus);

        add(shape, gbc);

        JPanel dimension = new JPanel();
        JLabel heightLbl = new JLabel("Height: ");
        JLabel widthLbl = new JLabel("Width: ");
        JLabel sideLbl = new JLabel("Side: ");
        JLabel radius1Lbl = new JLabel("Radius 1: ");
        JLabel radius2Lbl = new JLabel("Radius 2: ");
        JTextField heightTF = new JTextField(10);
        JTextField widthTF = new JTextField(10);
        JTextField sideTF = new JTextField(10);
        JTextField radius1TF = new JTextField(10);
        JTextField radius2TF = new JTextField(10);
        heightLbl.setLabelFor(heightTF);
        widthLbl.setLabelFor(widthTF); 
        sideLbl.setLabelFor(sideTF);
        radius1Lbl.setLabelFor(radius1TF);
        radius2Lbl.setLabelFor(radius2TF);

        dimension.add(heightLbl);
        dimension.add(heightTF);
        dimension.add(widthLbl);
        dimension.add(widthTF);
        dimension.add(sideLbl);
        dimension.add(sideTF);
        dimension.add(radius1Lbl);
        dimension.add(radius1TF);
        dimension.add(radius2Lbl);
        dimension.add(radius2TF);

        add(dimension, gbc);  

        gbc.gridwidth = GridBagConstraints.REMAINDER;

        drawPane = new DrawPane();

        gbc.weightx = 1;
        gbc.weighty = 1;
        gbc.fill = gbc.BOTH;      

        JPanel draw = new JPanel();
        JLabel areaLbl = new JLabel("Area: ");
        JTextField areaTF = new JTextField(10);
        areaTF.setEditable(false);
        JLabel volumeLbl = new JLabel("Volume: ");
        JTextField volumeTF = new JTextField(10);
        volumeTF.setEditable(false); 
        JButton paint = new JButton("Draw & Calculate");

        draw.add(paint);
        draw.add(drawPane);
        draw.add(areaLbl);
        draw.add(areaTF);
        draw.add(volumeLbl);
        draw.add(volumeTF); 
        add(draw, gbc);

            paint.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                double height = 0;
                double width = 0;
                double side = 0;
                double radius1 = 0;
                double radius2 = 0;
                double area, volume;
                try {
                height = Double.parseDouble(heightTF.getText());
                width = Double.parseDouble(widthTF.getText());
                side = Double.parseDouble(sideTF.getText());
                radius1 = Double.parseDouble(radius1TF.getText());
                radius2 = Double.parseDouble(radius2TF.getText());
                } catch(NumberFormatException ex) {
                    JOptionPane.showMessageDialog(draw, "Please enter a number value.");
                }

                if (circle.isSelected()) {
                    drawPane.setDrawableShape(DrawableShape.CIRCLE);
                    area = 3.14 * radius1 * radius1;
                    areaTF.setText(" "+ area);
                } 
                else if (square.isSelected()) {
                    drawPane.setDrawableShape(DrawableShape.SQUARE);
                    area = side * side;
                    areaTF.setText(" " + area);
                }
                else if (triangle.isSelected()) {
                    drawPane.setDrawableShape(DrawableShape.TRIANGLE);
                    area = 0.5 * width * height;
                    areaTF.setText(" " + area);
                }
                else if (rectangle.isSelected()) {
                     drawPane.setDrawableShape(DrawableShape.RECTANGLE);
                    area = height * width;
                    areaTF.setText(" " + area);
                }
                else if (sphere.isSelected()) {

                    volume = (4 / 3) * 3.14 * radius1 * radius1 * radius1;
                    volumeTF.setText(" " + volume);
                }
                else if (cube.isSelected()) {

                    volume = (side * side * side);
                    volumeTF.setText(" " + volume);
                }
                else if (cylinder.isSelected()) {

                    volume = (3.14 * radius1 * radius1 * height);
                    volumeTF.setText(" " + volume);
                } 
                else if (cone.isSelected()) {
                    volume = (3.14 * radius1 * radius1 * height) / 3;
                    volumeTF.setText(" " + volume);
                }
                else if (torus.isSelected()) {
                    volume = 2 * 3.14 * 3.14 * radius1 * radius1 * radius2;
                    volumeTF.setText(" " + volume);
                }
            }
        });

      }

}

DrawStuff class

import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.ButtonGroup;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JRadioButton;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class DrawStuff extends JFrame {

    public static void main(String[] args) {
        new DrawStuff();
    }

    public DrawStuff() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                     UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
            } catch (ClassNotFoundException | InstantiationException |     IllegalAccessException | UnsupportedLookAndFeelException ex) {
                ex.printStackTrace();
            }

            JFrame frame = new JFrame("Shape Calculator");
            frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            frame.add(new ControlPane());
            frame.pack();
            frame.setLocationRelativeTo(null);
            frame.setVisible(true);
        }
    });
}
}

绘图面板class

import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.ButtonGroup;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JRadioButton;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class DrawPane extends JPanel {

    private DrawableShape drawableShape;

    public DrawPane() {
    }

    public void setDrawableShape(DrawableShape drawableShape) {
        this.drawableShape = drawableShape;
        repaint();
    }

    public DrawableShape getDrawableShape() {
        return drawableShape;
    }

    @Override
    public Dimension getPreferredSize() {
        return new Dimension(200, 200);
    }

    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        Graphics2D g2d = (Graphics2D) g.create();
        DrawableShape shape = getDrawableShape();
        if (shape != null) {
            int width = getWidth() - 20;
            int height = getHeight() - 20;
            int size = Math.min(width, height);

            int x = (getWidth() - size) / 2;
            int y = (getHeight() - size) / 2;
            if (shape == DrawableShape.CIRCLE) {
                g2d.fillOval(x, y, size, size);
            } else if (shape == DrawableShape.SQUARE) {
                g2d.fillRect(x, y, size, size);
            } else if (shape == DrawableShape.TRIANGLE) {
                g2d.fillPolygon(new int[] {20, 40, 60}, new int[] {100, 50, 100}, 3);
            }
        }
        g2d.dispose();
    }

}

DrawableShape class

public enum DrawableShape {
    CIRCLE,
    SQUARE,
    TRIANGLE
}

Answer 1

为避免错误消息，您只需解析相关的 TextField，而不是全部。
例如，不需要为圆解析 heightTF 并且会抛出异常。
您可以通过将按钮动作侦听器更改为 paint.addActionListener(e -> calculate()); 来实现，其中计算定义如下：

//for simplicity only 3 shapes are handled:
private void calculate(){

    double area = 0, volume = 0;
    try {

        if (circle.isSelected()) {
            drawPane.setDrawableShape(DrawableShape.CIRCLE);
            double radius1 = Double.parseDouble(radius1TF.getText());
            area = 3.14 * radius1 * radius1;
        }
        else if (cube.isSelected()) {
            drawPane.setDrawableShape(null);
            double side = Double.parseDouble(sideTF.getText());
            volume = side * side * side;
        }
        else if (rectangle.isSelected()) {
            drawPane.setDrawableShape(DrawableShape.RECTANGLE);
            double height = Double.parseDouble(heightTF.getText());
            double width = Double.parseDouble(widthTF.getText());
            area = height * width;
        }

        areaTF.setText(" "+ area);
        volumeTF.setText(" " + volume);

    } catch(NumberFormatException ex) {
        JOptionPane.showMessageDialog(null, "Please enter a number value.");
    }
}

您需要将所有 TextField 个变量设为 class 个变量：

private final JTextField heightTF, widthTF, sideTF, radius1TF, areaTF, volumeTF;

为了更好更面向对象的解决方案定义 Shape :

interface Shape {
    double getArea();
    double getVolume();
    void draw(Graphics g, int x, int y);
}

并为每个形状实施它。例如：

class Circle implements Shape{

    private final int radius;
    Circle(int radius) {
        this.radius = radius;
    }

    @Override
    public double getArea() {
        return Math.PI * radius * radius;
    }

    @Override
    public double getVolume() {
        return 0;
    }

    @Override
    public void draw(Graphics g, int x, int y) {
        g.fillOval(x, y, radius, radius);
    }
}

使用 Java swing GUI 的形状计算器

Shape calculator using Java swing GUI

java

user-interface

swing

calculator