显示有问题的Jlist

Question

import java.awt.*;
import javax.swing.*;public class Test extends JFrame{
    
    public Test(){
        
        int number = 15;
        JPanel mainPanel = new JPanel();
        mainPanel.setLayout(new BorderLayout());
        
        JLabel[] label = new JLabel[number];
        for(int i = 0; i < number; i++){
            if(i % 2 == 0){
                label[i] = new JLabel("123gfdgdg");
            }else{
                label[i] = new JLabel("你好吗？");
            }
            label[i].setOpaque(false);
        }
        JList list = new JList(label);
        list.setCellRenderer(new MyCellRenderer());
        JScrollPane scrollPane = new JScrollPane(list);
        mainPanel.add(scrollPane,BorderLayout.CENTER);
        
        this.setPreferredSize(new Dimension(350,300));
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        getContentPane().add(mainPanel);
        pack();
        setVisible(true);
        
    }
    
    public static void main(String[] args){
        
        new Test();
    }
    
    private class MyCellRenderer extends JPanel implements ListCellRenderer  {
        
         public Component getListCellRendererComponent(JList list,
                                                       Object value,
                                                       int index,
                                                       boolean isSelected,
                                                       boolean cellHasFocus) {
             
                 setOpaque(false);
                 setLayout(new BorderLayout());
                 add((JLabel)value);
             
             
             if(isSelected){
                 setBackground(list.getSelectionBackground()); 
             }else{
                 setBackground(list.getBackground());
             }
             return this;
         }
     }    
}
为什么显示出来的字体会重在一起的？

Answer 1

import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Dimension;import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.ListCellRenderer;public class Test extends JFrame{
    
    public Test(){
        
        int number = 15;
        JPanel mainPanel = new JPanel();
        mainPanel.setLayout(new BorderLayout());
        
        String[] label = new String[number];
        for(int i = 0; i < number; i++){
            if(i % 2 == 0){
                label[i] = new String("123gfdgdg");
            }else{
                label[i] = new String("Hello");
            }
           
        }
        JList list = new JList(label);
        list.setCellRenderer(new MyCellRenderer());
        JScrollPane scrollPane = new JScrollPane(list);
        mainPanel.add(scrollPane,BorderLayout.CENTER);
        
        this.setPreferredSize(new Dimension(350,300));
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        getContentPane().add(mainPanel);
        pack();
        setVisible(true);
        
    }
    
    public static void main(String[] args){
        
        new Test();
    }
    
    private class MyCellRenderer extends JLabel implements ListCellRenderer  {
        
         public Component getListCellRendererComponent(JList list,
                                                       Object value,
                                                       int index,
                                                       boolean isSelected,
                                                       boolean cellHasFocus) {
             
                 setOpaque(false);
                 setLayout(new BorderLayout());
                 
                 setText(value.toString());
             
             
             if(isSelected){
                 setBackground(list.getSelectionBackground()); 
             }else{
                 setBackground(list.getBackground());
             }
             return this;
         }
     }    
}

Answer 2

把你的MyCellRenderer换成我的就可以了，注意红色部分！！！private class MyCellRenderer extends JPanel implements ListCellRenderer
    {
        private JLabel label = new JLabel();
        public Component getListCellRendererComponent(JList list,
                Object value,
                int index,
                boolean isSelected,
                boolean cellHasFocus)
        {            setOpaque(false);
            setLayout(new BorderLayout());
            this.label.setText(((JLabel) value).getText());
            add(this.label);
            if (isSelected)
            {
                setBackground(list.getSelectionBackground());
            }
            else
            {
                setBackground(list.getBackground());
            }            return this;
        }
    }

Answer 3

谢谢楼上两位兄弟，但问题是一楼的duhongltz，我是想将一个panel加到list里面，然后在里面在放几个图片和标签 ，就一个标签加入去布局不漂亮，三楼的chenkangwan如果用你这种方法的话那么if(isSelected)设置颜色那段就没反应了，我也试过你这种方法，如果单是为了设置颜色另加一个监听器好像有点夸张，想用回这个类里面的接口，不知有没更好的方法。

Answer 4

if (i % 2 == 0)
{
label[i] = new JLabel("123gfdgdg");
}
else
{
label[i] = new JLabel("                              你好吗？");
}
label[i].setOpaque(false);
加点空格就好了，标签和内容覆盖了

Answer 5

import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Dimension;import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.ListCellRenderer;public class Test extends JFrame{
    
    public Test(){
        
        int number = 15;
        JPanel mainPanel = new JPanel();
        mainPanel.setLayout(new BorderLayout());
        JPanel[] panels = new JPanel[number];
        JLabel[] label = new JLabel[number];
        for(int i = 0; i < number; i++){
            if(i % 2 == 0){
                label[i] = new JLabel("123gfdgdg");
            }else{
                label[i] = new JLabel("Hello");
            }
            label[i].setOpaque(false);
            panels[i] = new MyPanel();
            panels[i].add(label[i]);
        }
        JList list = new JList(panels);
        //list.setCellRenderer(new MyCellRenderer());
        JScrollPane scrollPane = new JScrollPane(list);
        mainPanel.add(scrollPane,BorderLayout.CENTER);
        
        this.setPreferredSize(new Dimension(350,300));
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        getContentPane().add(mainPanel);
        pack();
        setVisible(true);
        
    }
    
    public static void main(String[] args){
        
        new Test();
    }
    
//    private class MyCellRenderer extends JPanel implements ListCellRenderer  {
//        
//         public Component getListCellRendererComponent(JList list,
//                                                       Object value,
//                                                       int index,
//                                                       boolean isSelected,
//                                                       boolean cellHasFocus) {
//             
//                 setOpaque(false);
//                 setLayout(new BorderLayout());
//                 add((JLabel)value);
//
//                 
//             
//             
//             if(isSelected){
//                 setBackground(list.getSelectionBackground()); 
//             }else{
//                 setBackground(list.getBackground());
//             }
//             return this;
//         }
//     }
    private class MyPanel extends JPanel{
     MyPanel(){
     super();
     }
     public String toString(){
     JLabel label = (JLabel)getComponent(0);
     return label.getText();
     }
    }    
}
看看符合你的要求不。不过你要在panel中加其他组件 还要用到 renderer.

Answer 6

嗯嗯，多谢duhongltz。我就是想在加到list的panel里面加入另外一个panel和几个label，还是要用到renderer。请问duhongltz能否再给点提示，谢谢你了！