Question

我有这段代码想让JList谈话文字和图标必须做什么有人建议我制作标签清单，在表格中放置文字图标是否可能？怎么样？

在/////////////////上搜索嵌入式评论。

import javax.swing.JPanel;
import javax.swing.JButton;
import javax.swing.JLabel;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.Transferable;
import java.awt.datatransfer.UnsupportedFlavorException;
import java.awt.dnd.DropTarget;
import java.awt.dnd.DropTargetDragEvent;
import java.awt.dnd.DropTargetDropEvent;
import java.awt.dnd.DropTargetEvent;
import java.awt.dnd.DropTargetListener;
import java.io.File;
import java.io.IOException;
import java.util.List;
import javax.swing.DefaultListModel;
import javax.swing.Icon;
import javax.swing.JList;
import javax.swing.JScrollPane;
import javax.swing.filechooser.FileSystemView;

public class pan extends JPanel implements DropTargetListener {

private DefaultListModel listModel = new DefaultListModel();
private DropTarget dropTarget;
private JLabel jLabel1;
private JScrollPane jScrollPane1;
private JList list;

/**
 * Create the panel.
 */
public pan() {
    setLayout(null);        
    list = new JList();
    dropTarget = new DropTarget(list, this);
    list.setModel(listModel);
    list.setDragEnabled(true);
    //list.setTransferHandler(new FileTransferHandler());
    jScrollPane1 = new JScrollPane();

    jScrollPane1.setViewportView(list);
    jScrollPane1.setBounds(10, 150, 635, 330);
    add(jScrollPane1);

}
public void dragEnter(DropTargetDragEvent arg0) {
    // nothing
}

public void dragOver(DropTargetDragEvent arg0) {
    // nothing
}

public void dropActionChanged(DropTargetDragEvent arg0) {
    // nothing
}

public void dragExit(DropTargetEvent arg0) {
    // nothing
}

public void drop(DropTargetDropEvent evt) {
    int action = evt.getDropAction();
    evt.acceptDrop(action);
    try {
        Transferable data = evt.getTransferable();
        if (data.isDataFlavorSupported(DataFlavor.javaFileListFlavor)) {
              List<File> files = (List<File>) data.getTransferDat(DataFlavor.javaFileListFlavor);
            for (File file : files) {

    Icon icon=FileSystemView.getFileSystemView().getSystemIcon(file);
/////////////////listModel.addElement(filepath+icon);///////////////////////want code do this

            }
        }
    } catch (UnsupportedFlavorException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        evt.dropComplete(true);
    }
 }

}

解决了这个问题后，如果点击它会打开桌面，我将为每个元素添加动作到存储在列表中的路径。

Answer 1

FileDragList

import java.awt.*;
import java.awt.datatransfer.*;
import java.awt.dnd.*;
import javax.swing.*;
import javax.swing.border.LineBorder;
import javax.swing.filechooser.FileSystemView;
import java.io.*;
import java.util.List;

public class FileDropList extends JPanel implements DropTargetListener {

    private DefaultListModel listModel = new DefaultListModel();
    private DropTarget dropTarget;
    private JLabel jLabel1;
    private JScrollPane jScrollPane1;
    private JList list;

    /**
     * Create the panel.
     */
    public FileDropList() {
        //setLayout(null);        
        list = new JList();
        dropTarget = new DropTarget(list, this);
        list.setModel(listModel);
        list.setDragEnabled(true);
        FileListCellRenderer renderer = new FileListCellRenderer();
        list.setCellRenderer(renderer);
        //list.setTransferHandler(new FileTransferHandler());
        jScrollPane1 = new JScrollPane(list);

        //jScrollPane1.setBounds(10, 150, 635, 330);
        add(jScrollPane1);

    }
    public static void main(String[] args) throws Exception {
        Runnable r = new Runnable() {
            @Override
            public void run() {
                JPanel pan = new FileDropList();
                pan.setBorder(new LineBorder(Color.BLACK));
                JOptionPane.showMessageDialog(null, pan);
            }
        };
        SwingUtilities.invokeLater(r);
    }

    public void dragEnter(DropTargetDragEvent arg0) {
        // nothing
    }

    public void dragOver(DropTargetDragEvent arg0) {
        // nothing
    }

    public void dropActionChanged(DropTargetDragEvent arg0) {
        // nothing
    }

    public void dragExit(DropTargetEvent arg0) {
        // nothing
    }

    public void drop(DropTargetDropEvent evt) {
        int action = evt.getDropAction();
        evt.acceptDrop(action);
        try {
            Transferable data = evt.getTransferable();
            if (data.isDataFlavorSupported(DataFlavor.javaFileListFlavor)) {
                List<File> files = (List<File>) data.getTransferData(DataFlavor.javaFileListFlavor);
                for (File file : files) {
                    listModel.addElement(file);
                }
            }
        } catch (UnsupportedFlavorException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            evt.dropComplete(true);
        }
    }
}

/** A FileListCellRenderer for a File. */
class FileListCellRenderer extends DefaultListCellRenderer {

    private static final long serialVersionUID = -7799441088157759804L;
    private FileSystemView fileSystemView;
    private JLabel label;
    private Color textSelectionColor = Color.BLACK;
    private Color backgroundSelectionColor = Color.CYAN;
    private Color textNonSelectionColor = Color.BLACK;
    private Color backgroundNonSelectionColor = Color.WHITE;

    FileListCellRenderer() {
        label = new JLabel();
        label.setOpaque(true);
        fileSystemView = FileSystemView.getFileSystemView();
    }

    @Override
    public Component getListCellRendererComponent(
            JList list,
            Object value,
            int index,
            boolean selected,
            boolean expanded) {

        File file = (File)value;
        label.setIcon(fileSystemView.getSystemIcon(file));
        label.setText(fileSystemView.getSystemDisplayName(file));
        label.setToolTipText(file.getPath());

        if (selected) {
            label.setBackground(backgroundSelectionColor);
            label.setForeground(textSelectionColor);
        } else {
            label.setBackground(backgroundNonSelectionColor);
            label.setForeground(textNonSelectionColor);
        }

        return label;
    }
}

原始答案

import java.awt.datatransfer.*;
import java.awt.dnd.*;
import javax.swing.*;
import javax.swing.filechooser.FileSystemView;
import java.io.*;
import java.util.List;

public class FileDragList extends JPanel implements DropTargetListener {

    private static final long serialVersionUID = 1L;
    private DefaultListModel listModel = new DefaultListModel();
    private JScrollPane jScrollPane1;
    private JList list;

    /**
     * Create the panel.
     */
    public FileDragList() {
        setLayout(null);        
        list = new JList();
        DropTarget dropTarget = new DropTarget(list, this);
        list.setModel(listModel);
        list.setDragEnabled(true);
        FileListCellRenderer renderer = new FileListCellRenderer();
        list.setCellRenderer(renderer);
        //list.setTransferHandler(new FileTransferHandler());
        jScrollPane1 = new JScrollPane();

        jScrollPane1.setViewportView(list);
        jScrollPane1.setBounds(10, 150, 635, 330);
        add(jScrollPane1);

    }
    public static void main(String[] args) throws Exception {
        Runnable r = new Runnable() {
            @Override
            public void run() {
                JOptionPane.showMessageDialog(null, new FileDragList());
            }
        };
        SwingUtilities.invokeLater(r);
    }

    public void dragEnter(DropTargetDragEvent arg0) {
        // nothing
    }

    public void dragOver(DropTargetDragEvent arg0) {
        // nothing
    }

    public void dropActionChanged(DropTargetDragEvent arg0) {
        // nothing
    }

    public void dragExit(DropTargetEvent arg0) {
        // nothing
    }

    public void drop(DropTargetDropEvent evt) {
        int action = evt.getDropAction();
        evt.acceptDrop(action);
        try {
            Transferable data = evt.getTransferable();
            if (data.isDataFlavorSupported(DataFlavor.javaFileListFlavor)) {
                List<File> files = (List<File>) data.getTransferData(DataFlavor.javaFileListFlavor);
                for (File file : files) {

                    Icon icon=FileSystemView.getFileSystemView().getSystemIcon(file);
                    /////////////////listModel.addElement(filepath+icon);///////////////////////want code do this

                }
            }
        } catch (UnsupportedFlavorException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            evt.dropComplete(true);
        }
    }
}

Icon icon=FileSystemView.getFileSystemView().getSystemIcon(file);

哦对了..试试File Browser GUI的FileTreeCellRenderer变体。

就是这样，用于左边的树。

FileTreeCellRenderer

/** A TreeCellRenderer for a File. */
class FileTreeCellRenderer extends DefaultTreeCellRenderer {

    private FileSystemView fileSystemView;
    private JLabel label;

    FileTreeCellRenderer() {
        label = new JLabel();
        label.setOpaque(true);
        fileSystemView = FileSystemView.getFileSystemView();
    }

    @Override
    public Component getTreeCellRendererComponent(
        JTree tree,
        Object value,
        boolean selected,
        boolean expanded,
        boolean leaf,
        int row,
        boolean hasFocus) {

        DefaultMutableTreeNode node = (DefaultMutableTreeNode)value;
        File file = (File)node.getUserObject();
        label.setIcon(fileSystemView.getSystemIcon(file));
        label.setText(fileSystemView.getSystemDisplayName(file));
        label.setToolTipText(file.getPath());

        if (selected) {
            label.setBackground(backgroundSelectionColor);
            label.setForeground(textSelectionColor);
        } else {
            label.setBackground(backgroundNonSelectionColor);
            label.setForeground(textNonSelectionColor);
        }

        return label;
    }
}

更新

一个SSCCE，它使上面的渲染器适应列表。

enter image description here

import java.awt.*;
import javax.swing.*;
import javax.swing.filechooser.FileSystemView;
import java.io.File;

public class FileList {
    public static void main(String[] args) throws Exception {
        Runnable r = new Runnable() {
            @Override
            public void run() {
                JPanel gui = new JPanel(new BorderLayout(2,2));

                File userHome = new File(System.getProperty("user.home"));
                File[] files = userHome.listFiles();
                JList list = new JList(files);
                list.setCellRenderer(new FileListCellRenderer());
                gui.add(new JScrollPane(list));

                JOptionPane.showMessageDialog(null, gui);
            }
        };
        SwingUtilities.invokeLater(r);
    }
}

/** A FileListCellRenderer for a File. */
class FileListCellRenderer extends DefaultListCellRenderer {

    private static final long serialVersionUID = -7799441088157759804L;
    private FileSystemView fileSystemView;
    private JLabel label;
    private Color textSelectionColor = Color.BLACK;
    private Color backgroundSelectionColor = Color.CYAN;
    private Color textNonSelectionColor = Color.BLACK;
    private Color backgroundNonSelectionColor = Color.WHITE;

    FileListCellRenderer() {
        label = new JLabel();
        label.setOpaque(true);
        fileSystemView = FileSystemView.getFileSystemView();
    }

    @Override
    public Component getListCellRendererComponent(
        JList list,
        Object value,
        int index,
        boolean selected,
        boolean expanded) {

        File file = (File)value;
        label.setIcon(fileSystemView.getSystemIcon(file));
        label.setText(fileSystemView.getSystemDisplayName(file));
        label.setToolTipText(file.getPath());

        if (selected) {
            label.setBackground(backgroundSelectionColor);
            label.setForeground(textSelectionColor);
        } else {
            label.setBackground(backgroundNonSelectionColor);
            label.setForeground(textNonSelectionColor);
        }

        return label;
    }
}

如何使用图标和文本创建JList？

1 个答案:

原始答案

FileTreeCellRenderer

更新