将多个 JList 显示到 JFrame

Question

我试图将许多 JList 放在仅显示 2 个名称的不同滚动窗格中。我将 mt 列表存储在向量向量中，此结构表示一周中的几天，每天都有多个“班次”。

import java.awt.*;
import java.awt.event.*;
import java.util.Vector;
import javax.swing.*;
import javax.swing.event.*;

public class AutoScheduel extends JFrame{
private JList leftlist;
private JList leftlist1;
private JList tempList;
private int frameX = 50;
private int frameY = 50;
//private JList rightlist;
//private JButton movebutton;
static Employee Amanda = new Employee("Amanda",0,false); static Employee      Austin = new Employee("Austin",0,false); static Employee Conner = new Employee("Conner",0,false);
static Employee Faith = new Employee("Faith",0,false); static Employee Jospeh = new Employee("Jospeh",0,false); static Employee Lexi = new Employee("Lexi",0,false);
static Employee Matthew = new Employee("Matthew",0,false); static Employee     Samie = new Employee("Samie",0,false); static Employee Tanner = new     Employee("Tanner",0,false);
static Employee Valerie = new Employee("Valeire",0,false); static Employee     Will = new Employee("Will",0,false); static Employee Zack = new     Employee("Zack",0,false);
private static String[] employeesNames= {Amanda.getName(),Austin.getName(),Conner.getName(),Faith.getName(),Jospeh.getName(),
        Lexi.getName(),Matthew.getName(),Samie.getName(),Tanner.getName(),Valerie.getName(),Will.getName(),Zack.getName()};
private Vector<JList> weekday;
private Vector<JList> weekend;
private Vector<Vector<JList>> v;
public AutoScheduel(){
    super("Cambridge AutoSchedueler");
    setLayout(new FlowLayout());
    pack();
    setLocationRelativeTo(null);
    leftlist = new JList(employeesNames);
    leftlist.setVisibleRowCount(2);
    leftlist.setSelectionMode(ListSelectionModel.MULTIPLE_INTERVAL_SELECTION);
    //add(new JScrollPane(leftlist));

    leftlist1 = new JList(employeesNames);
    leftlist1.setVisibleRowCount(2);
    leftlist1.setSelectionMode(ListSelectionModel.MULTIPLE_INTERVAL_SELECTION);
    //add(new JScrollPane(leftlist));

    v = new Vector<Vector<JList>>();
    weekday = new Vector<JList>();
    weekend = new Vector<JList>();
    for(int i=0;i<6;i++){
        weekday.addElement(leftlist);
    }
    for(int i=0;i<5;i++){
        weekend.add(leftlist1);
    }
    for(int i=0;i<5;i++){
        v.add(weekday);
    }
    v.add(weekend);
    v.add(weekend);

    tempList = new JList();
    leftlist.setPreferredSize(new Dimension(50,20));
    //leftlist.setLocation(50, 50);
    //add(new JScrollPane(leftlist));
    //add(new JScrollPane(v.get(1).get(3)));


    for(int i = 0; i<v.size();i++){
        for(int j = 0 ; i<v.get(i).size();i++){
            tempList = v.get(i).get(j);
            frameY += 40;
            tempList.setLocation(frameX,frameY);
            add(new JScrollPane(tempList));
        }
        frameX += 50;
    }




}
public static void main(String[] args){
   AutoScheduel go = new  AutoScheduel();
   go.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   go.setSize(600, 600);

   go.setVisible(true);

}

}

目前，我得到一个列表，其中显示了我想要的正确列表，但该列表前面只有点表示有许多列表相互堆叠。我认为这是因为我正在使用流布局。当我尝试使用不同的列表，然后将其添加到 Jframe 中时，它可以工作，但由于我需要 34 个列表，我只想使用 for 循环将它们放入我的向量中。如果有人可以帮助 JFrame 中的格式化，那将是很棒的，我需要将它保存在一个数据结构中，在那里我仍然可以访问元素并设置为看起来像一个带有可选列表的一周。提前致谢

Answer 1

您需要为您希望显示的每个 JList 创建一个新 JList 和一个新模型。您当前的代码只创建了 3 个 JList，并尝试在 GUI 中重复放置它们，但这不起作用。

例如，假设您想在一周的 5 个工作日显示 5 个 JList，其中一个显示员工姓名，您可以创建一个 JList 集合并在 for 循环中创建 5 个 JList，每个都有模型。此外，不要从 Employee 对象中提取姓名，而是用实际的 Employee 对象填充 JList 并使用渲染器告诉 JList 仅显示员工姓名。例如：

import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.GridLayout;
import java.util.HashMap;
import java.util.Map;

import javax.swing.*;

@SuppressWarnings("serial")
public class Scheduler2 extends JPanel {
    private static final Employee2[] employees = { 
            new Employee2("Amanda", 0, false), 
            new Employee2("Austin", 0, false),
            new Employee2("Conner", 0, false), 
            new Employee2("Faith", 0, false), 
            new Employee2("Jospeh", 0, false),
            new Employee2("Lexi", 0, false), 
            new Employee2("Matthew", 0, false), 
            new Employee2("Samie", 0, false),
            new Employee2("Tanner", 0, false), 
            new Employee2("Valeire", 0, false), 
            new Employee2("Will", 0, false),
            new Employee2("Zack", 0, false) };
    private static final String[] WEEK_DAYS = { "Monday", "Tuesday", "Wednesday", "Thursday", "Friday" };

    // associates each list with the day of the week
    private Map<String, JList<Employee2>> weekDayListMap = new HashMap<>();

    public Scheduler2() {
        // layout to hold 1 row, multiple columns
        setLayout(new GridLayout(1, 0));
        // renderer that shows employee names only
        EmployeeCellRenderer cellRenderer = new EmployeeCellRenderer();
        for (int i = 0; i < WEEK_DAYS.length; i++) {
            // new model for each week
            DefaultListModel<Employee2> listModel = new DefaultListModel<>();
            for (Employee2 employee : employees) {
                // fill the model
                listModel.addElement(employee);
            }
            // new list for each day of the week with model
            JList<Employee2> list = new JList<>(listModel);
            list.setVisibleRowCount(4);
            list.setCellRenderer(cellRenderer); // so shows name only
            String prototypeName = "aaaaaaaaaaaaaaaaaaa";
            list.setPrototypeCellValue(new Employee2(prototypeName, 0, false));
            weekDayListMap.put(WEEK_DAYS[i], list); // put in collection (if needed)
            JScrollPane scrollPane = new JScrollPane(list);
            scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);

            // if we want a border around the jscrollpane showing the day of the week
            JPanel container = new JPanel(new BorderLayout());
            container.add(scrollPane);
            container.setBorder(BorderFactory.createTitledBorder(WEEK_DAYS[i]));
            add(container);
        }
    }

    // JList renderer to display only names
    private class EmployeeCellRenderer extends DefaultListCellRenderer {
        @Override
        public Component getListCellRendererComponent(JList<?> list, Object value, int index, boolean isSelected,
                boolean cellHasFocus) {
            if (value == null) {
                value = "";
            } else {
                Employee2 empl = (Employee2) value;
                value = empl.getName();
            }
            return super.getListCellRendererComponent(list, value, index, isSelected, cellHasFocus);
        }
    }

    private static void createAndShowGui() {
        JFrame frame = new JFrame("Scheduler2");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().add(new Scheduler2());
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> createAndShowGui());
    }
}

// you never gave us the employee class, so I had to create one of my own
class Employee2 {
    private String name;
    private int value;
    private boolean bool;

    public Employee2(String name, int value, boolean bool) {
        this.name = name;
        this.value = value;
        this.bool = bool;
    }

    public String getName() {
        return name;
    }

    public int getValue() {
        return value;
    }

    public boolean isBool() {
        return bool;
    }
}

---

关于，

你能解释一下你实际上是在哪里将列表添加到框架中的吗？

我将 JList 添加到 JScrollPane。然后我可以将 JScrollPane 添加到主 JPanel，即 this，但由于我想在 JScrollPane 周围加上一周中的某一天的边框，所以我创建了另一个 JPanel，称为容器，给它一个 BorderLayout，将 JScrollPane 添加到它，BorderLayout.CENTER（默认情况下），然后给这个外部“包装器”JPanel 一个带有星期字符串的标题边框。然后我将它添加到主 JPanel。都在这里：

// create JList w/ model
JList<Employee2> list = new JList<>(listModel);

// .....

// add JList to JScrollpane
JScrollPane scrollPane = new JScrollPane(list);


// .....

// create "wrapper" JPanel 
JPanel container = new JPanel(new BorderLayout());
container.add(scrollPane);  // and place JScrollPane into it
container.setBorder(BorderFactory.createTitledBorder(WEEK_DAYS[i]));

// add wrapper JPanel to the GUI
add(container);