我无法通过 JFileChooser 加载图形并实际显示它

问题描述

所以，我有一个从 JFrame 继承的类，它带有两个 JSplitPanes 和一个菜单栏。一个 JSplitPane 顶部有一个 JSplitPane，底部有一个 textarea，另外一个左右两个 JPanel。我想解析我通过 JFileChooser 选择的 pnml 文件（或更多，但我现在只是想让一个文件工作）。我可以选择一个文件，并通过打印文件名对其进行测试，该文件正在运行，但我无法在左侧 JPanel 中实际显示图形。也许有人可以帮我解决这个问题。这是我的课：

import pnml_parsing.Parser;
   
   import java.awt.BorderLayout;
   import java.awt.event.MouseAdapter;
   import java.awt.event.MouseEvent;
   import java.awt.event.ActionListener;
   import java.awt.event.ActionEvent;
   import java.io.File;
   import java.util.Arrays;
   
   import javax.swing.JComponent;
   import javax.swing.JFrame;
   import javax.swing.JLabel;
   import javax.swing.JPanel;
   import javax.swing.JScrollPane;
   import javax.swing.JSplitPane;
   import javax.swing.JTextArea;
   import javax.swing.JMenuBar;
   import javax.swing.JToolBar;
   import javax.swing.JMenu;
   import javax.swing.JMenuItem;
   import javax.swing.JButton;
   import javax.swing.JFileChooser;
   import javax.swing.filechooser.FileFilter;
   
   
   
   import org.graphstream.ui.swingViewer.ViewPanel;
   import org.graphstream.ui.view.Viewer;
   import org.graphstream.ui.view.ViewerPipe;
   
   
   
   public class Fenster_test extends JFrame {
       /** default serial version ID */
       private static final long serialVersionUID = 1L;
   
       
       private Controller controller;
   
       
       private ViewPanel viewPanel1;
       private ViewPanel viewPanel2;
   
       
       
       private JLabel statusLabel;
   
       
       JTextArea textfield = new JTextArea();
       JSplitPane leftRight = new JSplitPane();
       JComponent bottom = new JScrollPane(textfield);
       JPanel jpnlGraph = new JPanel(new BorderLayout());
       JPanel resultGraph = new JPanel(new BorderLayout());
       JLabel label = new JLabel();
       JToolBar tbar = new JToolBar();
       JMenuBar mbar = new JMenuBar();
       JMenu datei = new JMenu("Datei");
       JButton reset = new JButton("reset");
       JButton markerplus = new JButton("+");
       JButton markerminus = new JButton("-");
       JButton loescheEG = new JButton("EG löschen"); 
       JMenuItem dateiwahl = new JMenuItem("Datei auswählen");
       JMenuItem dateienwahl = new JMenuItem("Dateien auswählen");
       JFileChooser jfc = new JFileChooser();
       File[] files;
   
      
       
       
       final JSplitPane topBottom = new JSplitPane(JSplitPane.VERTICAL_SPLIT);
   
       public Fenster_test(String titel) {
           super(titel);
           
           jfc.setMultiSelectionEnabled(true);
           jfc.setFileFilter(new FileFilter() {
   
                  public String getDescription() {
                      return "PNML Dateien (*.pnml)";
                  }
   
                  public boolean accept(File f) {
                      if (f.isDirectory()) {
                          return true;
                      } else {
                          String filename = f.getName().toLowerCase();
                          return filename.endsWith(".pnml") || filename.endsWith(".pnml") ;
                      }
                  }
               });
               
   
   
       
       
           System.setProperty("org.graphstream.ui.renderer","org.graphstream.ui.j2dviewer.J2DGraphRenderer");
   
           // Erzeuge Controllers
           //controller = new Controller(this);
   
           // Layout des JFrames setzen
           this.setLayout(new BorderLayout());
   
           // Erzeuge und initialisiere ein Panel zur Anzeige des Graphen
           //initPanelGraph();
   
           // Einbetten des ViewPanels ins JPanel
           //jpnlGraph = new JPanel(new BorderLayout());
           //jpnlGraph.add(BorderLayout.CENTER,viewPanel1);
           
           // Füge das JPanel zum Haupt-Frame hinzu
           this.add(jpnlGraph,BorderLayout.CENTER);
           mbar.add(datei);
           tbar.add(loescheEG);
           tbar.add(markerplus);
           tbar.add(markerminus);
           tbar.add(reset);
           datei.add(dateiwahl);
           //initPanelGraph();
           controller = new Controller(jpnlGraph);
           label.setText("<No Graph>");
           jpnlGraph.add(label);
           dateiwahl.addActionListener(new ActionListener() {
               @Override
               public void actionPerformed(ActionEvent e) {
                   
   
                   jfc.showOpenDialog(null);
                   files = jfc.getSelectedFiles();
                   
                   
                   if(files == null) {
                       System.out.println("Keine Datei(en) ausgewählt");
                   }else {
                   
                       Parser parser = new Parser(files[0]);
                       parser.initParser(); 
                       parser.parse(); //parses File
                       
                       initPanelGraph(); 
                       
                       
                   }
                   if(files.length>1) {
                       Arrays.sort(files);
                       //mehrere Dateien durchlaufen
                       for(int i=0; i<files.length; i++) {
                           System.out.println("Datei "+files[i].getPath()+"ausgewählt");
                       }
                       
                   }
                   jfc.setCurrentDirectory(files[0].getParentFile());
               }
           });
           
           
   
           mbar.add(tbar);
           this.setJMenuBar(mbar);
           this.setDefaultCloSEOperation(JFrame.EXIT_ON_CLOSE);
           this.setBounds(200,200,400,300);
   
             
   
           topBottom.setTopComponent(leftRight);
           topBottom.setBottomComponent(bottom);
   
           leftRight.setLeftComponent(jpnlGraph);
           leftRight.setRightComponent(resultGraph);
   
           this.add(topBottom,BorderLayout.CENTER);
           this.setSize(1000,700);
           this.setVisible(true);
   
           topBottom.setDividerLocation(0.8);
           leftRight.setDividerLocation(0.5);
   
       }
   
       private void initPanelGraph() {
           Viewer viewer = new Viewer(controller.getGraph(),//this method actually converts my own model of my pnml-File to Nodes and Edges for graphstream
                   Viewer.ThreadingModel.GRAPH_IN_ANOTHER_THREAD);
           viewer.disableAutoLayout();
   
           viewPanel1 = viewer.adddefaultview(false);
   
           ViewerPipe viewerPipe = viewer.newViewerPipe();
   
           ClickListener clickListener = new ClickListener(controller);
   
           viewerPipe.addViewerListener(clickListener);
   
           viewPanel1.addMouseListener(new MouseAdapter() {
   
               @Override
               public void mousepressed(MouseEvent me) {
                   System.out.println("MyFrame - mousepressed: " + me);
                   viewerPipe.pump();
               }
   
               @Override
               public void mouseReleased(MouseEvent me) {
                   System.out.println("MyFrame - mouseReleased: " + me);
                   viewerPipe.pump();
               }
           });
       }

在我尝试使用 JFileChooser 并对 .pnml-path 进行硬编码之前，它运行良好。构造函数看起来像这样。现在我只是打电话给 new Fenster_test("Name of my Frame");在我的 main-Method 中，在我还在 main-method 中进行解析之前。

    public Fenster_test(String titel) {
        super(titel);
    
        System.setProperty("org.graphstream.ui.renderer","org.graphstream.ui.j2dviewer.J2DGraphRenderer");


        controller = new Controller(this);

        this.setLayout(new BorderLayout());

        
        initPanelGraph();


        jpnlGraph.add(BorderLayout.CENTER,viewPanel1);
        

        this.add(jpnlGraph,BorderLayout.CENTER);

        
        this.setDefaultCloSEOperation(JFrame.EXIT_ON_CLOSE);
        this.setBounds(200,300);

          

        topBottom.setTopComponent(leftRight);
        topBottom.setBottomComponent(bottom);

        leftRight.setLeftComponent(jpnlGraph);
        leftRight.setRightComponent(resultGraph);

        this.add(topBottom,BorderLayout.CENTER);
        this.setSize(1024,720);
       this.setVisible(true);

        topBottom.setDividerLocation(0.8);
        leftRight.setDividerLocation(0.5);
    
    }

    

解决方法

由于您没有提供最小的、可运行的示例，因此我创建了自己的示例。

这是一个简单的图像显示 GUI。

我用绘图 JFrame 创建了一个 JPanel。创建 JFrame 的代码位于 run 方法中。绘图 JPanel 是在单独的类中创建的。我扩展 JPanel 是因为我想覆盖 paintComponent 方法。

使用此代码创建一个简单的 GUI 来显示您的一张医学图像。一旦你开始工作，小心地将代码添加到你的简单 GUI 中。在您添加的每一点（

使用空布局和绝对定位不是一个好主意。 Swing 旨在与 layout managers 一起使用。

这是完整的可运行代码。

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

import javax.imageio.ImageIO;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.filechooser.FileNameExtensionFilter;

public class ImageDisplay implements Runnable {

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new ImageDisplay());
    }
    
    private ImageDisplayModel model;
    
    private ImagePanel imagePanel;
    
    private JFrame frame;
    
    public ImageDisplay() {
        this.model = new ImageDisplayModel();
    }
    
    @Override
    public void run() {
        frame = new JFrame("Image Display");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setJMenuBar(createMenuBar());
        
        imagePanel = new ImagePanel(model);
        frame.add(imagePanel,BorderLayout.CENTER);
        
        frame.pack();
        frame.setLocationByPlatform(true);
        frame.setVisible(true);
    }
    
    private JMenuBar createMenuBar() {
        JMenuBar menubar = new JMenuBar();
        
        JMenu filemenu = new JMenu("File"); 
  
        JMenuItem openitem = new JMenuItem("Open...");
        openitem.addActionListener(new OpenFileListener(this,model));
        filemenu.add(openitem);
        
        menubar.add(filemenu);
        
        return menubar;
    }
    
    public void updateImagePanel(int width,int height) {
        imagePanel.setPreferredSize(width,height);
        imagePanel.repaint();
        frame.pack();
    }
    
    public JFrame getFrame() {
        return frame;
    }
    
    public class ImagePanel extends JPanel {

        private static final long serialVersionUID = 1L;
        
        private ImageDisplayModel model;
        
        public ImagePanel(ImageDisplayModel model) {
            this.model = model;
            this.setPreferredSize(649,480);
        }
        
        public void setPreferredSize(int width,int height) {
            this.setPreferredSize(new Dimension(width,height));
        }
        
        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            
            BufferedImage image = model.getImage();
            if (image != null) {
                g.drawImage(image,this);
            }
        }
        
    }
    
    public class OpenFileListener implements ActionListener {
        
        private ImageDisplay frame;
        
        private ImageDisplayModel model;

        public OpenFileListener(ImageDisplay frame,ImageDisplayModel model) {
            this.frame = frame;
            this.model = model;
        }

        @Override
        public void actionPerformed(ActionEvent event) {
            JFileChooser chooser = new JFileChooser();
            FileNameExtensionFilter filter = new FileNameExtensionFilter(
                    "JPG & PNG Images","jpg","png");
            chooser.addChoosableFileFilter(filter);
            chooser.setFileSelectionMode(JFileChooser.FILES_ONLY);
            
            File file = model.getFile();
            if (file != null) {
                chooser.setCurrentDirectory(file);            
            }
            
            int result = chooser.showOpenDialog(frame.getFrame());
            if (result == JFileChooser.APPROVE_OPTION) {
                File selectedFile = chooser.getSelectedFile();
                model.setFile(selectedFile);
                BufferedImage image;
                try {
                    image = ImageIO.read(selectedFile);
                    model.setImage(image);
                    frame.updateImagePanel(image.getWidth(),image.getHeight());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        
    }
    
    public class ImageDisplayModel {
        
        private BufferedImage image;
        
        private File file;

        public BufferedImage getImage() {
            return image;
        }

        public void setImage(BufferedImage image) {
            this.image = image;
        }

        public File getFile() {
            return file;
        }

        public void setFile(File file) {
            this.file = file;
        }
        
    }

}