破碎的绘图程序。 Java的

时间：2014-03-02 21:31:59

标签： java

我正在制作一个简单的绘图程序，并且不会显示绘图面板。我不知道Circle类或drawingPanel类是否有问题。 colorButtons和sizeButtons确实显示，但drawingPanel没有。能帮帮我吗，请您花时间和提前谢谢！附：我在drawingFrame中添加了框架。

public class Assign72 {

public static void main(String[] args) {
    DrawingFrame f= new DrawingFrame();
    f.setTitle("Drawing Program");
    f.setSize(462,312);
    f.setLocationRelativeTo(null);
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    f.setVisible(true);
}

public class DrawingFrame extends JFrame implements ActionListener {
private DrawingPanel drawPanel;
private JPanel panel;
private JPanel colorPanel;
private JPanel sizePanel;
private JRadioButton redRadioButton;
private JRadioButton blueRadioButton;
private JRadioButton greenRadioButton;
private JRadioButton blackRadioButton;
private JRadioButton smallRadioButton;
private JRadioButton mediumRadioButton;
private JRadioButton largeRadioButton;
private JButton eraseButton;
private ButtonGroup colorButtonGroup;
private ButtonGroup sizeButtonGroup;
final int SMALL = 4;
final int MEDIUM = 8;
final int LARGE = 10;

public DrawingFrame() {

    colorPanel = new JPanel();
    sizePanel = new JPanel();

    redRadioButton = new JRadioButton();
    redRadioButton.setText("Red");
    colorPanel.add(redRadioButton);
    redRadioButton.addActionListener(this);

    blueRadioButton = new JRadioButton();
    blueRadioButton.setText("Blue");
    colorPanel.add(blueRadioButton);
    blueRadioButton.addActionListener(this);

    greenRadioButton = new JRadioButton();
    greenRadioButton.setText("Green");
    colorPanel.add(greenRadioButton);
    greenRadioButton.addActionListener(this);

    blackRadioButton = new JRadioButton();
    blackRadioButton.setText("Black");
    colorPanel.add(blackRadioButton);
    blackRadioButton.addActionListener(this);



    smallRadioButton = new JRadioButton();
    smallRadioButton.setText("Small");
    sizePanel.add(smallRadioButton);
    smallRadioButton.addActionListener(this);

    mediumRadioButton = new JRadioButton();
    mediumRadioButton.setText("Medium");
    sizePanel.add(mediumRadioButton);
    mediumRadioButton.addActionListener(this);

    largeRadioButton = new JRadioButton();
    largeRadioButton.setText("Large");
    sizePanel.add(largeRadioButton);
    largeRadioButton.addActionListener(this);
    colorButtonGroup = new ButtonGroup();
    sizeButtonGroup = new ButtonGroup();

    sizeButtonGroup.add(smallRadioButton);
    sizeButtonGroup.add(mediumRadioButton);
    sizeButtonGroup.add(largeRadioButton);

    colorButtonGroup.add(redRadioButton);

    colorButtonGroup.add(blueRadioButton);
    colorButtonGroup.add(greenRadioButton);
    colorButtonGroup.add(blackRadioButton);

    redRadioButton.setSelected(true);
    largeRadioButton.setSelected(true);
    JPanel configurePanel = new JPanel();
    configurePanel.add(new JButton("Configure"));

    // Will be right-aligned.


    // The full panel.
    panel = new JPanel();
    panel.setBackground(Color.YELLOW);



    drawPanel = new DrawingPanel(Color.RED, LARGE);
    drawPanel.setBackground( Color.WHITE );



    this.add(sizePanel, BorderLayout.PAGE_START);
    this.add(colorPanel, BorderLayout.PAGE_END);

    this.add(drawPanel,BorderLayout.CENTER);



}

@Override
public void actionPerformed(ActionEvent e) {
    // TODO Auto-generated method stub
    if (redRadioButton.isSelected())
        drawPanel.setCircleColor(Color.RED);
    if (greenRadioButton.isSelected())
        drawPanel.setCircleColor(Color.GREEN);
    if (blueRadioButton.isSelected())
        drawPanel.setCircleColor(Color.BLUE);
    if (blackRadioButton.isSelected())
        drawPanel.setCircleColor(Color.BLACK);
    if (smallRadioButton.isSelected())
        drawPanel.setCircleSize(SMALL);
    if (mediumRadioButton.isSelected())
        drawPanel.setCircleSize(MEDIUM);
    if (largeRadioButton.isSelected())
        drawPanel.setCircleSize(LARGE);

}
}

public class DrawingPanel extends JPanel implements MouseMotionListener {
private int circleSize;
private Color circleColor;
private Circle newCircle;
private Circle drawingCircle;

private ArrayList<Circle> circleArrayList = new ArrayList<Circle>();

DrawingPanel(Color colorValue, int size) {
    addMouseMotionListener(this);
}

public void setCircleColor(Color choice) {

}

public Color getCircleColor() {
    return circleColor;

}

public void setCircleDiameter(int diameter) {

}

public int getCircleSize() {
    return circleSize;

}

public void paintComponent(Graphics g) {
    super.paintComponents(g);
    Iterator<Circle> circleIterator = circleArrayList.iterator();
    Circle drawCircle;
    while (circleIterator.hasNext()) {
        drawCircle = (Circle) circleIterator.next();
        drawCircle.draw(g);
    }
}

public void mouseDragged(MouseEvent event) {
    if (event.isMetaDown()) {
        newCircle = new Circle(getCircleSize(), event.getPoint(),
                this.getBackground());
        newCircle = new Circle(getCircleSize(), event.getPoint(),
                getCircleColor());
        circleArrayList.add(newCircle);
        repaint();

    }
}

@Override
public void mouseMoved(MouseEvent arg0) {
    // TODO Auto-generated method stub

}
}






   public class Circle {
private int size;
private Point point;
private Color color;

public Circle(int size, Point point, Color color) {
    setSize(size);
    setLocation(point);
    setColor(color);
}

public int getSize() {
    return size;

}

public void setSize(int size) {

}

public Point getLocation() {
    return point;

}

public void setLocation(Point point) {

}

public Color getColor() {
    return color;

}

public void setColor(Color color) {

}

public void draw(Graphics g) {
    getLocation();
    setColor(color);

    setSize(size);
    setColor(color);

    g.fillOval(point.x, point.y, size, size);

}
}

2 个答案:

答案 0 :(得分：1)

问题是您的代码是不成文的：

public void setCircleColor(Color choice) {

}

显然setCircleColor 什么都不做。所以你需要做的第一件事是完成代码编写。填写所有这些空方法：

public void setCircleColor(Color choice) {
    circleColor = choice;
}

然后你的draw方法没有设置Graphics上下文的颜色，所以你需要这样做：

public void draw(Graphics g) {
    //getLocation();
    //setColor(color);

    //setSize(size);
    //setColor(color);

    g.setColor(color);
    g.fillOval(point.x, point.y, size, size);
}

（那些其他方法调用不起作用。）

然后在某处您需要为这些值设置默认值，否则它们从0开始为空。

DrawingPanel(Color colorValue, int size) {
    setCircleColor(colorValue);
    setCircleSize(size);
    addMouseMotionListener(this);
}

最后一件事是你的mouseDragged事件有一些问题。

public void mouseDragged(MouseEvent event) {
    //if (event.isMetaDown()) {
        //newCircle = new Circle(getCircleSize(), event.getPoint(),
        //        this.getBackground());
        newCircle = new Circle(getCircleSize(), event.getPoint(),
                getCircleColor());
        circleArrayList.add(newCircle);
        repaint();

    //}
}
  • isMetaDown可能没有按照您的想法行事。元键对应于Mac'Command'键和Windows'Windows'键。
  • 您正在创建newCircle两次。我不确定哪一个应该是'正确的'。我假设不是第一个，因为第一个将Circle的颜色设置为面板的背景颜色（在这种情况下它将不可见）。

在这些变化之后，似乎或多或少有效：

Circles

更多说明：

  • 从中吸取的教训是，你不能指望不完整的代码可以做任何完整的事情。
  • 您应该阅读Initial Threads。您应该在EDT上创建GUI，方法是通过调用main将代码包装在invokeLater中。
  • 您的代码有编译错误，您没有提及。主要是我必须更改所有inner classes to nested classes并且有一些方法调用似乎在某些时候被重命名（例如drawPanel.setCircleSize似乎应该是drawPanel.setCircleDiameter）。当您发布完整的代码示例时，除非问题是关于编译错误，否则它们应该是可编译的。

以下是包含所有这些更改的功能代码以及一些次要的更改：

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;

public class Assign72 {
    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                DrawingFrame f= new DrawingFrame();
                f.setTitle("Drawing Program");
                f.setSize(462,312);
                f.setLocationRelativeTo(null);
                f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                f.setVisible(true);
            }
        });
    }

    public static class DrawingFrame
    extends JFrame
    implements ActionListener {
        private DrawingPanel drawPanel;
        private JPanel panel;
        private JPanel colorPanel;
        private JPanel sizePanel;
        private JRadioButton redRadioButton;
        private JRadioButton blueRadioButton;
        private JRadioButton greenRadioButton;
        private JRadioButton blackRadioButton;
        private JRadioButton smallRadioButton;
        private JRadioButton mediumRadioButton;
        private JRadioButton largeRadioButton;
        private JButton eraseButton;
        private ButtonGroup colorButtonGroup;
        private ButtonGroup sizeButtonGroup;

        static final int SMALL = 4; // constants are static
        static final int MEDIUM = 8;
        static final int LARGE = 10;

        public DrawingFrame() {
            colorPanel = new JPanel();
            sizePanel = new JPanel();

            redRadioButton = new JRadioButton();
            redRadioButton.setText("Red");
            colorPanel.add(redRadioButton);
            redRadioButton.addActionListener(this);

            blueRadioButton = new JRadioButton();
            blueRadioButton.setText("Blue");
            colorPanel.add(blueRadioButton);
            blueRadioButton.addActionListener(this);

            greenRadioButton = new JRadioButton();
            greenRadioButton.setText("Green");
            colorPanel.add(greenRadioButton);
            greenRadioButton.addActionListener(this);

            blackRadioButton = new JRadioButton();
            blackRadioButton.setText("Black");
            colorPanel.add(blackRadioButton);
            blackRadioButton.addActionListener(this);

            smallRadioButton = new JRadioButton();
            smallRadioButton.setText("Small");
            sizePanel.add(smallRadioButton);
            smallRadioButton.addActionListener(this);

            mediumRadioButton = new JRadioButton();
            mediumRadioButton.setText("Medium");
            sizePanel.add(mediumRadioButton);
            mediumRadioButton.addActionListener(this);

            largeRadioButton = new JRadioButton();
            largeRadioButton.setText("Large");
            sizePanel.add(largeRadioButton);
            largeRadioButton.addActionListener(this);
            colorButtonGroup = new ButtonGroup();
            sizeButtonGroup = new ButtonGroup();

            sizeButtonGroup.add(smallRadioButton);
            sizeButtonGroup.add(mediumRadioButton);
            sizeButtonGroup.add(largeRadioButton);

            colorButtonGroup.add(redRadioButton);

            colorButtonGroup.add(blueRadioButton);
            colorButtonGroup.add(greenRadioButton);
            colorButtonGroup.add(blackRadioButton);

            redRadioButton.setSelected(true);
            largeRadioButton.setSelected(true);
            JPanel configurePanel = new JPanel();
            configurePanel.add(new JButton("Configure"));

            // Will be right-aligned.

            // The full panel.
            panel = new JPanel();
            panel.setBackground(Color.YELLOW);

            drawPanel = new DrawingPanel(Color.RED, LARGE);
            drawPanel.setBackground( Color.WHITE );

            this.add(sizePanel, BorderLayout.PAGE_START);
            this.add(colorPanel, BorderLayout.PAGE_END);

            this.add(drawPanel,BorderLayout.CENTER);
        }

        @Override
        public void actionPerformed(ActionEvent e) {
            if (redRadioButton.isSelected())
                drawPanel.setCircleColor(Color.RED);
            if (greenRadioButton.isSelected())
                drawPanel.setCircleColor(Color.GREEN);
            if (blueRadioButton.isSelected())
                drawPanel.setCircleColor(Color.BLUE);
            if (blackRadioButton.isSelected())
                drawPanel.setCircleColor(Color.BLACK);
            if (smallRadioButton.isSelected())
                drawPanel.setCircleDiameter(SMALL);
            if (mediumRadioButton.isSelected())
                drawPanel.setCircleDiameter(MEDIUM);
            if (largeRadioButton.isSelected())
                drawPanel.setCircleDiameter(LARGE);
        }
    }

    public static class DrawingPanel
    extends JPanel
    implements MouseMotionListener {
        private int circleSize;
        private Color circleColor;
        private Circle newCircle;
        private Circle drawingCircle;

        private ArrayList<Circle> circleArrayList = new ArrayList<Circle>();

        DrawingPanel(Color colorValue, int size) {
            setCircleColor(colorValue);
            setCircleDiameter(size);
            addMouseMotionListener(this);
        }

        public void setCircleColor(Color choice) {
            circleColor = choice;
        }

        public Color getCircleColor() {
            return circleColor;
        }

        public void setCircleDiameter(int diameter) {
            circleSize = diameter;
        }

        public int getCircleSize() {
            return circleSize;
        }

        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponents(g);

            // use regular for loop
            for(Circle c : circleArrayList) {
                c.draw(g);
            }
        }

        @Override
        public void mouseDragged(MouseEvent event) {
            newCircle = new Circle(getCircleSize(), event.getPoint(),
                    getCircleColor());
            circleArrayList.add(newCircle);
            repaint();
        }

        @Override
        public void mouseMoved(MouseEvent arg0) {}
    }

    public static class Circle {
        private int size;
        private Point point;
        private Color color;

        public Circle(int size, Point point, Color color) {
            setSize(size);
            setLocation(point);
            setColor(color);
        }

        public int getSize() {
            return size;
        }

        public void setSize(int size) {
            this.size = size;
        }

        public Point getLocation() {
            return point;
        }

        public void setLocation(Point point) {
            this.point = point;
        }

        public Color getColor() {
            return color;
        }

        public void setColor(Color color) {
            this.color = color;
        }

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

还有很多其他方法可以改进，但有太多建议要做。那将编译并执行。

答案 1 :(得分：0)

很可能你的绘图板存在但不涂漆。

可能是因为它可能不透明。

尝试在绘图面板上使用setOpaque(true);。

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