如何设置JCheckBox使用JScrollPane？

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。任何时候只是不要让我解决这个问题。我添加JList？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

在你的循环，你设置你的滚动窗格的视景到最后JCheckBox的，这将是见过的唯一一个。如果你想要在scrollpane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循环中的单个JPanel。然后将该JPanel添加到JScrollPane的视口视图。

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); // !! 

的另一个问题是在这里：

getContentPane().setLayout(null); 

虽然空布局和setBounds()似乎为Swing像最简单的和最好的方式新手创建复杂的图形用户界面的，更多的Swing GUI的是你创造更严重的困难你会在使用它们时遇到。它们在GUI大小调整时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会完全失败，在所有平台或屏幕分辨率与原始窗口不同时，它们看起来都很糟糕。

您将需要了解布局管理器并使用它们。