Question

I want to make JCheckBox List to use arraylist into this left side JScrollPane.但是这个JScrollPane只是粘贴并添加最后一个索引JCheckBox。任何时刻都不能让我解决这个问题。我添加JList吗？我想尽快解决这个问题。这是我的代码。

package dimi.voca;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import java.util.ArrayList;
import javax.swing.JCheckBox;
import javax.swing.ScrollPaneConstants;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import java.awt.event.ActionListener;
import java.awt.ScrollPane;
import java.awt.event.ActionEvent;
import javax.swing.JTextArea;
import javax.swing.Box;
import javax.swing.JList;

public class LearnSelect extends JFrame
{
    public LearnSelect() {
        super("DimiVoca in PC");

        JPanel panel = new JPanel();
        setSize(650, 500);

        getContentPane().setLayout(null);

        JScrollPane scrollPane = new JScrollPane();

        JList list = new JList();
        panel.add(list);

        scrollPane.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);
        scrollPane.setToolTipText("");
        scrollPane.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS);
        scrollPane.setBounds(28, 10, 200, 441);
        getContentPane().add(scrollPane);

        ArrayList<JCheckBox> Day = new ArrayList<JCheckBox>();
        String label[] = {  "Day 1", "Day 2", "Day 3", "Day 4", "Day 5", "Day 6",
                            "Day 7", "Day 8", "Day 9", "Day 10", "Day 11", "Day 12",
                            "Day 13", "Day 14", "Day 15", "Day 16", "Day 17", "Day 18", 
                            "Day 19", "Day 20", "Day 21", "Day 22", "Day 23", "Day 24", 
                            "Day 25", "Day 26", "Day 27", "Day 28", "Day 29", "Day 30", 
                            "Day 31", "Day 32", "Day 33", "Day 34", "Day 35", "Day 36", 
                            "Day 37", "Day 38", "Day 39", "Day 40", "Day 41", "Day 42", 
                            "Day 43", "Day 44", "Day 45", "Day 46", "Day 47", "Day 48", 
                            "Day 49", "Day 50", "Day 51", "Day 52", "Day 53", "Day 54", 
                            "Day 55", "Day 56", "Day 57", "Day 58", "Day 59", "Day 60"};
        for(int i = 0; i <= label.length - 1; i++)
        {
            JCheckBox checkbox = new JCheckBox(label[i]);
            Day.add(checkbox);
            scrollPane.setViewportView(checkbox);
        }

        JScrollPane scrollPane_1 = new JScrollPane();
        scrollPane_1.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_NEVER);
        scrollPane_1.setToolTipText("");
        scrollPane_1.setBounds(227, 10, 200, 441);
        getContentPane().add(scrollPane_1);

        JButton close = new JButton("\uB2EB\uAE30");
        close.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) 
            {
                dispose();
            }
        });
        close.setBounds(481, 428, 97, 23);
        getContentPane().add(close);

        JButton start = new JButton("\uC2DC\uC791");
        start.setBounds(481, 395, 97, 23);
        getContentPane().add(start);

        JCheckBox isRandom = new JCheckBox("\uB79C\uB364 \uD5C8\uC6A9");
        isRandom.setBounds(481, 100, 145, 23);
        getContentPane().add(isRandom);

        JCheckBox loadCreate = new JCheckBox("Create\uC5D0\uC11C \uBC1B\uC544\uC624\uAE30");
        loadCreate.setBounds(481, 150, 145, 23);
        getContentPane().add(loadCreate);

        setVisible(true);
    }
}

Answer 1

在for循环中，您将滚动窗格的视口视图设置为最后一个JCheckBox，它将是唯一可见的视图。如果你想在滚动窗格中看到所有JCheckBox，那么在for循环之前创建一个JPanel，给它一个GridLayout，并将你的JCheckBox添加到for循环中的这个单独的JPanel。然后将该JPanel添加到JScrollPane的视口视图中。

JPanel dayPanel = new JPanel(new GridLayout(0, 1)); // !!

ArrayList<JCheckBox> Day = new ArrayList<JCheckBox>();
String label[] = { "Day 1", "Day 2", "Day 3", "Day 4", "Day 5", "Day 6", "Day 7", "Day 8",
        "Day 9", "Day 10", "Day 11", "Day 12", "Day 13", "Day 14", "Day 15", "Day 16",
        "Day 17", "Day 18", "Day 19", "Day 20", "Day 21", "Day 22", "Day 23", "Day 24",
        "Day 25", "Day 26", "Day 27", "Day 28", "Day 29", "Day 30", "Day 31", "Day 32",
        "Day 33", "Day 34", "Day 35", "Day 36", "Day 37", "Day 38", "Day 39", "Day 40",
        "Day 41", "Day 42", "Day 43", "Day 44", "Day 45", "Day 46", "Day 47", "Day 48",
        "Day 49", "Day 50", "Day 51", "Day 52", "Day 53", "Day 54", "Day 55", "Day 56",
        "Day 57", "Day 58", "Day 59", "Day 60" };
for (int i = 0; i <= label.length - 1; i++) {
    JCheckBox checkbox = new JCheckBox(label[i]);
    Day.add(checkbox);
    // !! scrollPane.setViewportView(checkbox);
    dayPanel.add(checkbox);  // !!
}

scrollPane.setViewportView(dayPanel);  // !!

另一个问题是：

getContentPane().setLayout(null);

虽然null布局和setBounds()似乎是Swing新手，比如创建复杂GUI的最简单和最好的方法，但是你创建的Swing GUI越多，使用它们时会遇到更严重的困难。当GUI调整大小时，它们不会调整组件的大小，它们很难增强或维护，当它们放置在滚动窗格中时它们完全失败，当它们在所有平台上观看时或者与原始平台不同的屏幕分辨率时，它们看起来很糟糕。

您需要了解布局管理器并使用它们。

如何设置JCheckBox以使用JScrollPane？

1 个答案: