Java ArrayLists 转换成 JList [英] Java ArrayLists into JList

问题描述

好的，所以我正在做我的库存的一小部分.我记下了大部分.我正在尝试将字符串项添加到 ArrayList，然后将其添加到 JList.但是，编译时出现此错误:

OK so I'm doing a small part of my inventory. I got MOST of it down. I'm trying to add string items to an ArrayList then add that to a JList. However, I'm getting this error when I compile:

C:\Users\Dan\Documents\DanJavaGen\inventory.java:30: cannot find symbol
symbol  : constructor JList(java.util.ArrayList<java.lang.String>)
location: class javax.swing.JList
        list = new JList(arr);

这可能是我犯的一些菜鸟错误......:/

It's probably some rookie mistake I am making ... :/

代码:

import java.applet.Applet;
import java.awt.*;
import javax.swing.*;
import javax.swing.JList;
import java.awt.event.*;
import java.util.ArrayList;
import java.io.*;
import java.util.*;

public class inventory extends JApplet implements MouseListener {

public static String newline;
public static JList list;
int gold = 123;

    public void init() {



ArrayList<String> arr = new ArrayList<String>();
arr.add("Hatchet");
arr.add("Sword");
arr.add("Shield");
arr.add(gold + " Gold");
System.out.println("You have " + arr.size() + " items in your inventory.");
showInventory(arr);



        list = new JList(arr);

        add(list);

        list.addMouseListener(this);

        list.setVisible(true);

    }

public static void showInventory (ArrayList<String> theList) {
for (int i = 0; i < theList.size(); i++) {
System.out.println(theList.get(i));
}
}


    public void mousePressed(MouseEvent e) { }

    public void mouseReleased(MouseEvent e) {
        Object index = list.getSelectedValue();
       System.out.println("You have selected: " + index);
    }

    public void mouseEntered(MouseEvent e) { }

    public void mouseExited(MouseEvent e) { }

    public void mouseClicked(MouseEvent e) { }




    public void paint(Graphics g) {

    }
}

推荐答案

JList 提供了一个构造函数 JList(Object[])，你可以在解压你的 之后调用它>ArrayList 使用 toArray():

JList provides a constructor JList(Object[]) which you can call after unpacking your ArrayList<String> using toArray():

list = new JList(arr.toArray())

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