java - 我正在尝试使用图像的坐标在 imageIcon 上绘制一个填充的矩形，并且该矩形显示为关闭

Question

最终，在我解决了这个小细节之后，它将收到一个建筑物和房间号来勾勒出所述建筑物和房间号，因此很容易找到，但我无法在一个房间上精确地绘制矩形.

package programSTLApp;
/*
   Program to request the classroom no. in STLCC and Display the location of 
   that classroom.
 */

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

public class STLApp extends JFrame
{
    private JLabel imageLabel;
    private JButton button;
    private JPanel imagePanel;
    private JPanel buttonPanel;

public STLApp()
{
    super("My STLCC Class Locator");   

    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setLayout(new BorderLayout());
    buildImagePanel();
    buildButtonPanel();

    add(imagePanel, BorderLayout.CENTER);
    add(buttonPanel,BorderLayout.SOUTH);

    pack();
    setVisible(true);
}

private void buildImagePanel()
{
    imagePanel = new JPanel();
    imageLabel = new JLabel("Click the button to see the drawing indicating "
            + "the location of your class");
    imagePanel.add(imageLabel);
}

private void buildButtonPanel()
{
    buttonPanel = new JPanel();

    button = new JButton("Get Image");

    button.addActionListener(new ButtonListener());
    buttonPanel.add(button);
}

private class ButtonListener implements ActionListener
{
    @Override
    public void actionPerformed(ActionEvent e)
    {
        ImageIcon SiteLayoutFV = new ImageIcon("D:\\B120.jpg");
        imageLabel.setIcon(SiteLayoutFV);
        imageLabel.setText(null);
        pack();
    }

}
public void paint(Graphics g)
    {
        super.paint(g);
        g.setColor(Color.RED);
        g.fillRect(55,740,164,815);
    }


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


    }
}

Answer 1

正如已经指出的那样，顶级容器不是执行自定义绘画的可研究类，这些容器有很多功能可以使绘画变得容易。

相反，为自己创建一个自定义组件，从类似于 JPanel 的东西扩展而来，并覆盖它的 paintComponent方法。

渲染地板 Pane 后，您可以在其顶部渲染自定义元素。

如何存储此信息由您决定，但基本上，您需要某种映射，让您可以发言/发言并获得 Shape应该被渲染。

因为楼层 map 可能会 float (例如，它可能并不总是在 0x0 处呈现)，您需要能够 translate坐标使得 Shape将始终匹配。

看看...

• Performing Custom Painting
• 2D Graphics

更多详情

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class FloorPlan {

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

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

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        private BufferedImage floorPlan;

        private Rectangle myOffice = new Rectangle(150, 50, 32, 27);

        public TestPane() {
            try {
                floorPlan = ImageIO.read(new File("floorPlan.png"));
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }

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

        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            Graphics2D g2d = (Graphics2D) g.create();
            if (floorPlan != null) {

                int x = (getWidth() - floorPlan.getWidth()) / 2;
                int y = (getHeight() - floorPlan.getHeight()) / 2;
                g2d.drawImage(floorPlan, x, y, this);

                g2d.setColor(Color.RED);
                g2d.translate(x, y);
                g2d.draw(myOffice);

            }

            g2d.dispose();
        }
    }

}