Java 如何在jlist中添加图像

Question

提问by

Hi i have created a j list and there i want to add an image before any text in that text how can i do this i tried but i am not able to achieve my goal i want to add an image before list element"Barmer".

嗨，我已经创建了 aj 列表，并且我想在该文本中的任何文本之前添加一个图像，我该怎么做我试过但我无法实现我的目标我想在列表元素“Barmer”之前添加一个图像。

    public class ListDemo extends JPanel
                          implements ListSelectionListener {
        private JList list;
        private DefaultListModel listModel;


        public ListDemo() {
            super(new BorderLayout());

            listModel = new DefaultListModel();
            listModel.addElement("Barmer");
           //Create the list and put it in a scroll pane.
            list = new JList(listModel);
            list.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
            list.setSelectedIndex(0);
            list.addListSelectionListener(this);
            list.setVisibleRowCount(5);
            list.setBackground(new java.awt.Color(0,191,255));;
           list.setFont(new Font("Arial",Font.BOLD,35));
            list.setForeground( Color.white );
            list.setFixedCellHeight(60);
    list.setFixedCellWidth(50);
    list.setBorder(new EmptyBorder(10,20, 20, 20));


            JScrollPane listScrollPane = new JScrollPane(list);
            add(listScrollPane, BorderLayout.CENTER);

        }
         public void valueChanged(ListSelectionEvent e) {

        }

        private static void createAndShowGUI() {
            //Create and set up the window.
            JFrame frame = new JFrame("ListDemo");
            frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

            //Create and set up the content pane.
            JComponent newContentPane = new ListDemo();
            newContentPane.setOpaque(true); //content panes must be opaque
            frame.setContentPane(newContentPane);
           frame.setExtendedState(JFrame.MAXIMIZED_BOTH); 
    frame.setUndecorated(true);

            //Display the window.
            frame.pack();
            frame.setVisible(true);
        }



          public static void main(String[] args) {

                    createAndShowGUI();

        }
    }

How can i do this help me?

我该怎么做才能帮到我？

Thanks in advance

提前致谢

Answer 1

采纳答案by Paul Samsotha

You want to look as a custom ListCellRenderer. You can look at Provding a Custom Rendererfor JComboBox. It the same for a JList. The tutorial over-complicates a bit for simple scenarios. They extends JLabeland implements ListCellRenderwhere you have to implement a few unnecessary things if you just want basic functionality but with am image.

你想看起来像一个自定义ListCellRenderer. 你可以看一下Provding自定义呈现的JComboBox。对于一个JList. 对于简单的场景，本教程过于复杂。如果您只想要基本功能但使用图像，它们会扩展JLabel并且implements ListCellRender您必须实现一些不必要的东西。

You can just instead extendsor create a anonymous DefaultListCellRenderand just get the JLabelrender component and add to it, like setting Fontand ImageIcon. Something like this

您可以改为extends或创建一个匿名对象，DefaultListCellRender然后获取JLabel渲染组件并添加到其中，例如设置Font和ImageIcon. 像这样的东西

public class MarioListRenderer extends DefaultListCellRenderer {

    Font font = new Font("helvitica", Font.BOLD, 24);

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

        JLabel label = (JLabel) super.getListCellRendererComponent(
                list, value, index, isSelected, cellHasFocus);
        label.setIcon(imageMap.get((String) value));
        label.setHorizontalTextPosition(JLabel.RIGHT);
        label.setFont(font);
        return label;
    }
}

What happens is that each cell uses this renderer and calls the getListCellRendererComponentmethod. The valueyou see passed to the method is the value in each cell, in my case, one of the character names in the list. I then map that to the corresponding ImageIconand set the Iconon the JLabelrenderer component.

发生的情况是每个单元格都使用此渲染器并调用该getListCellRendererComponent方法。在value你看到传递给方法是在每个单元格的值，在我的情况，在列表中的角色的名字之一。然后我将其映射到相应的ImageIcon并Icon在JLabel渲染器组件上设置。

enter image description here

import java.awt.Component;
import java.awt.Dimension;
import java.awt.Font;
import java.util.HashMap;
import java.util.Map;
import javax.swing.DefaultListCellRenderer;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JScrollPane;
import javax.swing.SwingUtilities;

public class MarioList {

    private final Map<String, ImageIcon> imageMap;

    public MarioList() {
        String[] nameList = {"Mario", "Luigi", "Bowser", "Koopa", "Princess"};
        imageMap = createImageMap(nameList);
        JList list = new JList(nameList);
        list.setCellRenderer(new MarioListRenderer());

        JScrollPane scroll = new JScrollPane(list);
        scroll.setPreferredSize(new Dimension(300, 400));

        JFrame frame = new JFrame();
        frame.add(scroll);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }

    public class MarioListRenderer extends DefaultListCellRenderer {

        Font font = new Font("helvitica", Font.BOLD, 24);

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

            JLabel label = (JLabel) super.getListCellRendererComponent(
                    list, value, index, isSelected, cellHasFocus);
            label.setIcon(imageMap.get((String) value));
            label.setHorizontalTextPosition(JLabel.RIGHT);
            label.setFont(font);
            return label;
        }
    }

    private Map<String, ImageIcon> createImageMap(String[] list) {
        Map<String, ImageIcon> map = new HashMap<>();
        for (String s : list) {
            map.put(s, new ImageIcon(
                    getClass().getResource("/marioscaled/" + s + ".png")));
        }
        return map;
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                new MarioList();
            }
        });
    }
}

Side Note

边注

AndrewThompson is correct about just checking the tutorial first. You could have easily found an example implementation, then tried it out. Swing tutorials can be found here. Look under the Using Swing Components for how to use different components.
Swing apps should be run on the Event Dispatch Thread (EDT). You can do so by wrapping your creatAndShowGui()in a SwinUtilities.invokeLater.... See more at Initial Threads

AndrewThompson 关于首先检查教程是正确的。您可以很容易地找到一个示例实现，然后尝试一下。Swing 教程可以在这里找到。查看使用 Swing 组件以了解如何使用不同的组件。
Swing 应用程序应该在事件调度线程 (EDT) 上运行。您可以通过将您creatAndShowGui()的SwinUtilities.invokeLater.... 在初始线程中查看更多信息

UPDATEwith internet images.

使用互联网图片更新。

enter image description here

new Code

新代码

import java.awt.Component;
import java.awt.Dimension;
import java.awt.Font;
import java.net.URL;
import java.util.HashMap;
import java.util.Map;
import javax.swing.DefaultListCellRenderer;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JScrollPane;
import javax.swing.SwingUtilities;

public class MarioList {

    private final Map<String, ImageIcon> imageMap;

    public MarioList() {
        String[] nameList = {"Mario", "Luigi", "Bowser", "Koopa", "Princess"};
        imageMap = createImageMap(nameList);
        JList list = new JList(nameList);
        list.setCellRenderer(new MarioListRenderer());

        JScrollPane scroll = new JScrollPane(list);
        scroll.setPreferredSize(new Dimension(300, 400));

        JFrame frame = new JFrame();
        frame.add(scroll);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }

    public class MarioListRenderer extends DefaultListCellRenderer {

        Font font = new Font("helvitica", Font.BOLD, 24);

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

            JLabel label = (JLabel) super.getListCellRendererComponent(
                    list, value, index, isSelected, cellHasFocus);
            label.setIcon(imageMap.get((String) value));
            label.setHorizontalTextPosition(JLabel.RIGHT);
            label.setFont(font);
            return label;
        }
    }

    private Map<String, ImageIcon> createImageMap(String[] list) {
        Map<String, ImageIcon> map = new HashMap<>();
        try {
            map.put("Mario", new ImageIcon(new URL("http://i.stack.imgur.com/NCsHu.png")));
            map.put("Luigi", new ImageIcon(new URL("http://i.stack.imgur.com/UvHN4.png")));
            map.put("Bowser", new ImageIcon(new URL("http://i.stack.imgur.com/s89ON.png")));
            map.put("Koopa", new ImageIcon(new URL("http://i.stack.imgur.com/QEK2o.png")));
            map.put("Princess", new ImageIcon(new URL("http://i.stack.imgur.com/f4T4l.png")));
        } catch (Exception ex) {
            ex.printStackTrace();
        }
        return map;
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                new MarioList();
            }
        });
    }
}

Java 如何在jlist中添加图像

提问by

采纳答案by Paul Samsotha

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提问by

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