从JScrollPane中的对象的ArrayList显示变量 [英] Displaying a variable from an ArrayList of objects in a JScrollPane

问题描述

一个具有静态ArrayList和一个设置了UI，我想要显示每个对象foodName的列表，因为这将是可以在在线菜单GUI上选择和订购的食品。

one with a static ArrayList and one with a UI that is set up, I am wanting to show a list of each of the objects foodName because this is going to be food items that can be selected and ordered on an online menu GUI.

    public class MenuItem
    {  
        private String foodName;
        private String foodType;
        private float price;
        private int calories;    

        /**
         * Constructor for objects of class MenuItem
         */
        public MenuItem(String nameFood, String typeFood, float foodPrice, int caloryCount)

        {     
        foodName = nameFood;
        foodType = typeFood;
        price = foodPrice;
        calories = caloryCount;

       } 

       public String foodName()   
       {
         return foodName;       
       }

       public String foodType()   
       {
          return foodType; 
       }

       public float price()
       {
           return price;
       }

       public int  calories()
       {
           return calories;
        }
    }

以上是每个MenuItem的类。 p>

This above is my class for each MenuItem.

import java.util.ArrayList;


/**
 * 
 * ArrayList for the class, will hold all food items
 * @author Jonathan
 * @version 1.0
 *
 */

public class RestaurantArrayList extends MenuItem
{


    public RestaurantArrayList(String nameFood, String typeFood, float foodPrice, int caloryCount) {
        super(nameFood, typeFood, foodPrice, caloryCount);

    }

    public static final ArrayList<MenuItem> items;

    static 
    {
        items = new ArrayList<>();
        items.add(new MenuItem("Coca Cola", "Drink", 3.00f, 38));
        items.add(new MenuItem("Fanta Orange", "Drink", 3.00f, 31 ));
        items.add(new MenuItem("Glass of Red Wine", "Drink", 5.00f, 85));
        items.add(new MenuItem("Glass of White Wine", "Drink", 5.00f, 82));
        items.add(new MenuItem("Carling", "Drink", 3.50f, 189));
        items.add(new MenuItem("Fosters", "Drink", 3.50f, 378));
        items.add(new MenuItem("Water", "Drink", 0.00f, 0));
        items.add(new MenuItem("Breads", "Starter", 5.00f, 150));
        items.add(new MenuItem("Cold Meat", "Starter", 5.00f, 150));
        items.add(new MenuItem("Potato Skins and Barbeque Sauce", "Starter", 5.00f, 500));
        items.add(new MenuItem("Cold Meat", "Starter", 5.00f, 400));
        items.add(new MenuItem("Garlic Bread and Cheese", "Starter", 4.50f, 450));
        items.add(new MenuItem("Steak", "Main", 13.50f, 750));
        items.add(new MenuItem("Cheese and Bacon Burger", "Main", 8.00f, 850));
        items.add(new MenuItem("Spaghetti Cabonara", "Main", 7.00f, 675));
        items.add(new MenuItem("Steak", "Main", 13.50f, 378));
        items.add(new MenuItem("Seafood Paella", "Main", 10.00f, 850));
    }
}

这是我已经设置的ArrayList类。我想要在文本区域显示食物的名称，但我不知道该怎么做。如果有人可以帮助那将是伟大的。感谢

Here is the ArrayList Class I have also set up. I am wanting to just display the name of the food in the text area but I am not sure how to do this. If anyone can help that would be great. Thanks

JScrollPane scrollPane_1 = new JScrollPane();
        scrollPane_1.setBounds(219, 50, 134, 309);
        contentPane.add(scrollPane_1);

这是一段代码设置JScrollPane的代码，我想要的信息是

this is a little snippet of code setting up a JScrollPane as well that I am wanting the information to be displayed inside, which is within its own GUI class.

推荐答案

我将使用 JList 与自定义 DefaultListCellRenderer 。单元格渲染器确定单元格中的对象是如何显示的，因此在您的情况下，您需要 JList 中的 MenuItem 对象，渲染器应该提取用于显示的名称字符串。这是我起草的：

I would use a JList with a custom DefaultListCellRenderer. Cell renderers determine how the objects in a cell is shown, so in your case you want MenuItem objects in your JList and the renderer should extract the name string for showing. Here's what I drafted:

创建一个JList并将其添加到JScrollPane的视口中：

Create a JList and add it to the viewport of a JScrollPane:

JList foodList = new JList(RestaurantArrayList.items.toArray());
foodList.setCellRenderer(new FoodListRenderer());
JScrollPane scr = new JScrollPane(foodList);

和自定义ListCellRenderer类：

and custom ListCellRenderer class:

class FoodListRenderer extends DefaultListCellRenderer {

@Override
public Component getListCellRendererComponent(JList list, Object value, int index, boolean isSelected, boolean cellHasFocus) {
    String name = ((MenuItem) value).foodName();
    return super.getListCellRendererComponent(list, name, index, isSelected, cellHasFocus);
}}

这篇关于从JScrollPane中的对象的ArrayList显示变量的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！