問題描述

我有一個圖像，我在其上使用預(yù)定義的位置來創(chuàng)建具有顏色的圖形對象.通過單擊鼠標(biāo)，我嘗試在其上創(chuàng)建一些帶有顏色的橢圓.其實(shí)我達(dá)不到這個目的.因?yàn)?，?dāng)我單擊預(yù)定義位置時，我可以在其上創(chuàng)建一個橢圓，但是當(dāng)我單擊另一個預(yù)定義位置時，第一個橢圓消失了.

I have an image and I use pre-defined positions on it to create graphic objects with colors . With a mouse click I try to create some ovals on it with colors . Actually I couldn't achieve this objective. Because , when I click on a pre-defined position I could create an oval on it but when I click on another pre-defined position first oval has gone.

一個橢圓可以通過點(diǎn)擊兩次來移除.

An oval can be removed by click on it twice.

看看這個，

public class PrintDialog extends javax.swing.JDialog{
private int count = 0;
private int count_1 = 0;

/**
 * Creates new form PrintFeetDialog
 */
public PrintDialog(java.awt.Frame parent, boolean modal)
{
    super(parent, modal);
    initComponents();
    ImagePanel panel = new ImagePanel("Areas.jpg");
    this.getContentPane().add(panel);
    this.setResizable(false);
    this.setLocationRelativeTo(panel);
    this.pack();
}

private void formMouseClicked(java.awt.event.MouseEvent evt)                                  
{                                      
    // TODO add your handling code here:
    System.out.println("Print y - " + evt.getY());
    System.out.println("Print x - " + evt.getX());

    if ((evt.getX() >= 68 && evt.getX() <= 84) && (evt.getY() >= 44 && evt.getY() <= 72))
    {
        Graphics g = getGraphics();
        count++;
        if (count == 1)
        {
            g.setColor(Color.red);
            g.fillOval(66, 52, 20, 20);
            //  repaint();
        } else if (count > 1)
        {
            g.setColor(new Color(-3692899));
            g.fillOval(66, 52, 20, 20);
            repaint();
            count = 0;
        }
        g.dispose();
    }

    if ((evt.getX() >= 137 && evt.getX() <= 157) && (evt.getY() >= 50 && evt.getY() <= 75))
    {
        Graphics g1 = getGraphics();
        count_1++;
        if (count_1 == 1)
        {
            g1.setColor(Color.RED);
            g1.fillOval(137, 54, 20, 20);
        } else if (count_1 > 1)
        {
            g1.setColor(new Color(-3692899));
            g1.fillOval(66, 52, 20, 20);
            repaint();
            count_1 = 0;
        }
        g1.dispose();
    }
}
}   

圖像面板類

public class ImagePanel extends JPanel{

private Image img;

public ImagePanel(String img, String str)
{
    //this(new ImageIcon(img).getImage());    
}

public ImagePanel(String path)
{
    Image img = new ImageIcon(path).getImage();
    this.img = img;
    Dimension size = new Dimension(img.getWidth(null), img.getHeight(null));
    setPreferredSize(size);
    setMinimumSize(size);
    setMaximumSize(size);
    setSize(size);
    setLayout(null);

     try
    {
        BufferedImage image = ImageIO.read(new File(path));
        int rgb = image.getRGB(66, 52);
        System.out.println("Colour is: "+rgb);
    }
    catch(IOException e)
    {
        e.printStackTrace();
    }
}

public void paintComponent(Graphics g)
{
    super.paintComponent(g);
    g.drawImage(img, 0, 0, null);
}
}

有什么想法嗎?

謝謝.

推薦答案

不要使用 getGraphics，這不是自定義繪畫的工作方式，請參閱 在 AWT 和 Swing 中繪畫 和 執(zhí)行自定義繪畫了解更多詳情

Don't use getGraphics, this is not how custom painting works, see Painting in AWT and Swing and Performing Custom Painting for more details

基本思想是，您需要某種List，在其中添加每個形狀.當(dāng) mouseClicked 發(fā)生時，您遍歷列表并檢查鼠標(biāo)單擊是否出現(xiàn)了其中一個形狀，如果是，則從 List 中刪除該形狀，如果不是，您在單擊它的位置創(chuàng)建一個新形狀并將其添加到 List.

The basic idea is, you need some kind of List, into which you add each shape. When the mouseClicked occurs, you iterate through list and check to see if the mouse clicked occur one of the shapes, if it was, you remove the shape from the List, if not, you create a new shape at the point it was clicked and add it to the List.

然后，您可以在 paintComponent 方法中使用此 List 來物理繪制形狀.

You then use this List inside the paintComponent method to physically paint the shapes.

此示例擴(kuò)展了您的 ImagePanel 添加自定義繪畫

This example extends your ImagePanel adding in the custom painting

import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Shape;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.geom.Ellipse2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class Test {

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

    public Test() {
        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("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.add(new DrawPane("/Volumes/Disk02/Dropbox/MegaTokyo/thumnails/0.jpg"));
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class ImagePanel extends JPanel {

        private Image img;

        public ImagePanel(String img, String str) {
            //this(new ImageIcon(img).getImage());    
        }

        public ImagePanel(String path) {
            Image img = new ImageIcon(path).getImage();
            this.img = img;
            try {
                BufferedImage image = ImageIO.read(new File(path));
                int rgb = image.getRGB(66, 52);
                System.out.println("Colour is: " + rgb);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        @Override
        public Dimension getPreferredSize() {
            return img == null ? new Dimension(200, 200) : new Dimension(img.getWidth(this), img.getHeight(this));          
        }

        @Override
        public void paintComponent(Graphics g) {
            super.paintComponent(g);
            g.drawImage(img, 0, 0, null);
        }
    }

    public class DrawPane extends ImagePanel {

        private List<Shape> shapes;

        public DrawPane(String img, String str) {
            super(img, str);
            init();
        }

        public DrawPane(String path) {
            super(path);
            init();
        }

        protected void init() {
            shapes = new ArrayList<>(25);
            addMouseListener(new MouseAdapter() {
                @Override
                public void mouseClicked(MouseEvent e) {
                    boolean clicked = false;
                    Iterator<Shape> it = shapes.iterator();
                    while (it.hasNext()) {
                        Shape shape = it.next();
                        if (shape.contains(e.getPoint())) {
                            it.remove();
                            clicked = true;
                            break;
                        }
                    }
                    if (!clicked) {
                        shapes.add(new Ellipse2D.Double(e.getX() - 10, e.getY() - 10, 20, 20));
                    }
                    repaint();
                }

            });
        }

        @Override
        public void paintComponent(Graphics g) {
            super.paintComponent(g); 
            Graphics2D g2d = (Graphics2D) g.create();
            g2d.setColor(Color.RED);
            for (Shape shape : shapes) {
                g2d.draw(shape);
            }
            g2d.dispose();
        }

    }

}

這篇關(guān)于java swing應(yīng)用程序中如何保留和刪除多個圖形對象?的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網(wǎng)！