Question

我制作了自己的包来存储我编程任务的草稿，然后我做了最后的草稿。我将最终草稿复制并粘贴到我教授给出的实际包中，但它根本不会编译并给我所有这些错误。我试过做项目＆gt;干净，但没有帮助。我不明白文件如何在一个地方工作而不是另一个地方。

这是我的代码

package gui;


import filters.EdgeDetectFilter;
import filters.EdgeHighlightFilter;
import filters.Filter;
import filters.FlipHorizontalFilter;
import filters.FlipVerticalFilter;
import filters.GrayscaleFilter;
import filters.SharpenFilter;
import filters.SoftenFilter;
import image.PixelImage;

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
//import java.awt.EventQueue;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;


import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.WindowConstants;
import javax.swing.border.EmptyBorder;    


public class SnapShopGUI {

    private final JFrame myFrame; 

    private final JPanel myMenuPanel;

    private final JPanel myTopPanel;

    private final JPanel myBottomPanel;

    private final JPanel myImagePanel;

    private JButton myOpen;

    private JButton mySave;

    private JButton myClose;

    private JFileChooser myFileChooser;

    private PixelImage myImage;

    private JLabel myLabel;

//  private String currentDirectory;

    private ArrayList<Filter> myFilters;

    private ArrayList<JButton> myFilterButtons;



    /*
     * Initializes all fields.
     */
    public SnapShopGUI() {
        myFrame = new JFrame("Test Layout");
        myFrame.getContentPane().setLayout(new BorderLayout());

        myMenuPanel = new JPanel(new BorderLayout());

        myTopPanel = new JPanel(new GridLayout(0, 1, 6, 6));
        myTopPanel.setBorder(new EmptyBorder(10, 10, 3, 10));

        myBottomPanel = new JPanel(new GridLayout(0, 1, 6, 6));         
        myBottomPanel.setBorder(new EmptyBorder(3, 10, 10, 10));  

        myImagePanel = new JPanel(new BorderLayout());

        myLabel = new JLabel();
//        final ImageIcon icon = new ImageIcon(getClass().getResource("seahawks_logo.gif")); 
//        myLabel.setIcon(icon);
        myFileChooser = new JFileChooser();
//      myFileChooser.setPreferredSize(new Dimension(500, 400));
        myFileChooser.setPreferredSize(new Dimension(600, 400));

        myFilterButtons = new ArrayList<JButton>();


    }
//    
    public void start() {

        myImagePanel.setBackground(Color.WHITE);

        myImagePanel.add(myLabel, BorderLayout.NORTH);

        createFilters();

        // BOTTOM MENU STUFF
        myBottomPanel.add(createOpenButton());
        myBottomPanel.add(createSaveButton());
        myBottomPanel.add(createCloseButton());

        myMenuPanel.add(myTopPanel, BorderLayout.NORTH);
        myMenuPanel.add(myBottomPanel, BorderLayout.SOUTH);     

        myFrame.add(myMenuPanel, BorderLayout.WEST);
        myFrame.add(myImagePanel);

        myFrame.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);

        myFrame.pack();
        myFrame.setVisible(true);
        myFrame.setLocationRelativeTo(null); // put this last to center window
    }

    public void createFilters() {

        myFilters = new ArrayList<Filter>();
        myFilters.add(new EdgeDetectFilter());
        myFilters.add(new EdgeHighlightFilter());
        myFilters.add(new FlipHorizontalFilter());
        myFilters.add(new FlipVerticalFilter());
        myFilters.add(new GrayscaleFilter());
        myFilters.add(new SharpenFilter());
        myFilters.add(new SoftenFilter());

        for (Filter filter : myFilters) {
            myTopPanel.add(createFilterButton(filter));         
        }
    }

    public JButton createFilterButton(final Filter theFilter) {
        JButton fButton = new JButton(theFilter.getDescription());
//      fButton.setPreferredSize(new Dimension(120, 30));
        fButton.setEnabled(false);
        myFilterButtons.add(fButton);

        class FilterActionListener implements ActionListener {

            @Override
            public void actionPerformed(ActionEvent e) {
                theFilter.filter(myImage);
                myLabel.setIcon(new ImageIcon(myImage));

            }           
        }

        fButton.addActionListener(new FilterActionListener());

        return fButton;
    }
//    
    public JButton createOpenButton() {
        ImageIcon openButtonIcon = new ImageIcon(getClass().getResource("open.gif"));
        myOpen = new JButton("Open...", openButtonIcon);


        class OpenActionListener implements ActionListener {

            @Override
            public void actionPerformed(final ActionEvent e) {
                int returnVal = myFileChooser.showOpenDialog(myFrame);

                if (returnVal == JFileChooser.APPROVE_OPTION) {
                    File file = myFileChooser.getSelectedFile();
                    try {
                        myImage = PixelImage.load(file);
                        myLabel.setIcon(new ImageIcon(myImage));
                        myFrame.pack();
                    } catch (final IOException fileErr) {
                        JOptionPane.showMessageDialog(myFrame,
                                "The selected file did not contain an image!",
                                "Error!",
                                JOptionPane.ERROR_MESSAGE);
                    }
                    myFrame.setMinimumSize(myFrame.getSize());

                    for (JButton button : myFilterButtons) {
                        button.setEnabled(true);
                    }

                    mySave.setEnabled(true);
                    myClose.setEnabled(true);
                }           
            }
        }

        myOpen.addActionListener(new OpenActionListener());

        return myOpen;

    }

    public JButton createSaveButton() { 
        final ImageIcon saveButtonIcon = new ImageIcon(getClass().getResource("save.gif"));
        mySave = new JButton("Save As...", saveButtonIcon);
        mySave.setEnabled(false);

        class SaveActionListener implements ActionListener {

            @Override
            public void actionPerformed(final ActionEvent e) {
                myFileChooser.setCurrentDirectory(new File(System.getProperty("user.dir")));
                int returnVal = myFileChooser.showSaveDialog(myFrame);

                if (returnVal == JFileChooser.APPROVE_OPTION) {
                    try {
                        myImage.save(myFileChooser.getSelectedFile());
                    } catch (IOException e1) {
                        e1.printStackTrace();
                    }           
                }           
            }
        }

        mySave.addActionListener(new SaveActionListener());
        return mySave;      
    }

    public JButton createCloseButton() {
        final ImageIcon closeButtonIcon = new ImageIcon(getClass().getResource("close.gif"));
        myClose = new JButton("Close", closeButtonIcon);
        myClose.setEnabled(false);

        class CloseActionListener implements ActionListener {

            @Override
            public void actionPerformed(final ActionEvent e) {
                myLabel.setIcon(null);  
                for (JButton button : myFilterButtons) {
                    button.setEnabled(false);
                }
                myClose.setEnabled(false);
                mySave.setEnabled(false);
                myFrame.setMinimumSize(myMenuPanel.getSize());
                myFrame.pack();
            }       
        }

        myClose.addActionListener(new CloseActionListener());

        return myClose;
    }
}

这些是我得到的错误。我没有把它们放在我的草稿包上，但在我教授提供的包裹上，我得到了这些错误：

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
    at javax.swing.ImageIcon.<init>(Unknown Source)
    at gui.SnapShopGUI.createOpenButton(SnapShopGUI.java:188)
    at gui.SnapShopGUI.start(SnapShopGUI.java:133)
    at gui.SnapShopMain$1.run(SnapShopMain.java:36)
    at java.awt.event.InvocationEvent.dispatch(Unknown Source)
    at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
    at java.awt.EventQueue.access$500(Unknown Source)
    at java.awt.EventQueue$3.run(Unknown Source)
    at java.awt.EventQueue$3.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
    at java.awt.EventQueue.dispatchEvent(Unknown Source)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.run(Unknown Source)

Image

GUI文件在一个包中工作，但不在另一个包中运行

0 个答案: