GUI上的滾動條

Question

如何將垂直滾動條添加到此JTextArea框？

b6 = new JTextArea(); 
b6.setBounds(210,100, 170, 240); 

我試圖做一些或多或少是這樣的：

b6 = new JTextArea(); 
b6.setBounds(210,100, 170, 240); 
JScrollPane scroller = new JScrollPane(b6); 
add(scroller); 

使用時：

JScrollPane scroll = new JScrollPane(b6); 
scroll.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS); 
panel.add(scroll); 

加（滾動）;加有下劃線，說創建一個新的方法 '增加（JScrollPane的）' ......

主要代碼：

import java.awt.Color; 
import java.awt.Container; 
import java.awt.Point; 
import java.awt.Window; 
import java.awt.event.*; 
import java.util.Random; 

import javax.swing.*; 

public class RoPaSgame { 

    private static final int DISPOSE_ON_CLOSE = 0; 
    static int humanWon; // use for statistic 
    static int win=0; 
    static int total=0; 
    static int tie=0; 
    static String userName; 
    static JTextArea b6; 
    static JTextField b7; 
    static JButton quitFrame; 
    static Container panelAns, panel; 
    static JFrame frameAns, frame; 
    public static void main(String[] args){ // main 
     gamePanel();// launch main game 
     introductionPanel(); // launch instruction 
    } 

    private static void introductionPanel(){ // give the instruction to the game 
     String text="RoPaS Game is a strategic game played between\ntwo people. The choices are rock, paper or scissors\ngesture with the hand. Paper covers rock, rock\ncrushes scissors,scissors cuts paper."; 
     JOptionPane.showMessageDialog(null,text, "Introduction", 0, new ImageIcon(System.getProperty("user.dir")+"/image/5.jpg")); 
    } 

    private static void gamePanel(){ // the main game panel 

     frame = new JFrame("RoPaS Game"); //the main frame of the game 


     panel = frame.getContentPane(); // creating a container panel, so we can place buttons where we pleased 
     panel.setLayout(null); 

     String[] iconString= new String[3]; // creating icon string name so we can place the directory in with little effort 
     int[] boundInt= new int[3]; // same idea 

     for(int i=0; i<=2; i++){ // creating the conditions 
      iconString[i]=System.getProperty("user.dir")+"/image/"+i+".jpg"; 
      boundInt[i]=60+110*i; 
     } 

     JButton b1 = new JButton (" ", new ImageIcon(iconString[0])); 
     b1.setBackground(Color.white); 
     b1.setBounds(10,boundInt[0],150,100); 


     JButton b2 = new JButton (" ", new ImageIcon(iconString[1])); 
     b2.setBackground(Color.white); 
     b2.setBounds(10,boundInt[1],150,100); 

     JButton b3 = new JButton (" ", new ImageIcon(iconString[2])); 
     b3.setBackground(Color.white); 
     b3.setBounds(10,boundInt[2],150,100);//creating three buttons 

     JLabel l1 = new JLabel(new ImageIcon(System.getProperty("user.dir")+"/image/3.jpg")); 
     l1.setBounds(0, 0, 400, 50); 
     panel.add(l1);//creating a question button 

     JButton b4 = new JButton("Cheat"); 
     b4.setBackground(Color.DARK_GRAY); 
     b4.setForeground(Color.WHITE); 
     b4.setBounds(210, 350, 80, 30); //create a code button, this button will give you an automatic win 

     JButton b5 = new JButton("Quit"); //quit 
     b5.setBackground(Color.DARK_GRAY); 
     b5.setForeground(Color.WHITE); 
     b5.setBounds(300, 350, 80, 30); 

     b6 = new JTextArea(); 
     b6.setBounds(210,100, 170, 240); 




     JScrollPane mySchroll = new JScrollPane(b6, ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED,ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER); 
     panel.add(mySchroll); 

     Random ran = new Random(); 
     int ranName = ran.nextInt(99999); 

     b7 = new JTextField("Guest " + ranName); 
     b7.setBounds(260,60, 120, 25); 

     JLabel name = new JLabel("Name: "); 
     name.setBounds(210,60, 120, 25); 



     //place button on panel 
     panel.add(b1); 
     panel.add(b2); 
     panel.add(b3); 
     panel.add(b4); 
     panel.add(b5); 
     panel.add(b6); 
     panel.add(b7); 
     panel.add(name); 

     b1.addActionListener(//next three button will listen for which play pick and calculate the win in computeWinner 

       new ActionListener() { 
        public void actionPerformed(ActionEvent event) { 
         computeWinner(1); 
        }}); 

     b2.addActionListener(

       new ActionListener() { 
        public void actionPerformed(ActionEvent event) { 
         computeWinner(2); 
        }}); 

     b3.addActionListener(

       new ActionListener() { 
        public void actionPerformed(ActionEvent event) { 
         computeWinner(3); 
        }}); 

     b4.addActionListener(

       new ActionListener() {//cheat button, hit the guy and get a win 
        public void actionPerformed(ActionEvent event) { 
         win=win+1; 
         total=total+1; 

         JOptionPane.showMessageDialog(null,"You WIN again :)"+"\nWin/Loss rate: " + win+"/"+total+"\nTie: "+tie,"Cheater do prosper", 0, new ImageIcon(System.getProperty("user.dir")+"/image/4.jpg")); 

        }}); 


     b5.addActionListener(//quit the game and show three beat up guys 

       new ActionListener() { 
        public void actionPerformed(ActionEvent event) { 
         String text=" Joke:\n Ok, so in rock, paper, scissors \n I get howscissors beats paper and \n rock beats scissors butI don't get\n how paper beats rock is it supposed \n to magically wrap around rocks?\n why doesn't it do that to scissors?\n actually forget scissors why doesn't\n it do that to people? Paper should\n be able to suffocate us when we take\n notes and use daily contact with it\n if so we should be living in fear\n with our contact to it but we're not\n know why paper can't hurt us\n I always pick rock when I play\n when someone picks paper and says\n they beat me...I punch them in the face\n 'Oh, I'm sorry. I thought paper would\n protect you.' loser. \n\n Thank You for using RoPaS Game\n See you soon"; 
         JOptionPane.showMessageDialog(null,text, "Thank You, Goof Bye", 0, new ImageIcon(System.getProperty("user.dir")+"/image/6.gif")); 
         System.exit(0); 
        } 
       }); 


     frame.setSize(400, 420); 
     frame.getContentPane().setBackground(Color.LIGHT_GRAY); 
     frame.setVisible(true); 
     frame.setResizable(false); 
     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //set frame size and the game begins!  
    } 

    public static void computeWinner(int x){ // computing the winner 
     int computerChoice=computerRandomChoice(); 
     int humanChoice=x; 
     String text,text1=""; 
     String winningCombination= ""+Math.min(computerChoice, humanChoice)+Math.max(computerChoice, humanChoice); 

     switch(Integer.parseInt(winningCombination)){ 

     case 12: 
      text = "Paper wins"; 
      if(humanChoice==2) humanWon=1; 
      break; 
     case 13: 
      text = "Rock wins"; 
      if(humanChoice==1) humanWon=1; 
      break; 
     case 23: 
      text = "Scissors wins"; 
      if(humanChoice==3) humanWon=1; 
      break; 
     default: text="DRAW"; 
     humanWon=2; 
     tie=tie+1; 
     } 

     if(humanWon==1){ 
      text1="Human wins: "; 
      humanWon=0; 
      win=win+1; 
      total=total+1; 
     }else if(humanWon==2){ 
      text1=""; 
      humanWon=0;  
     }else{ 
      text1="Computer wins: "; 
      total=total+1; 
     } 


     frameAns = new JFrame("RoPaS Game"); 
     Point MainLoc = frame.getLocation(); 
     frameAns.setLocation(410 + (int)MainLoc.getX(), 0 + (int)MainLoc.getY()); 
     panelAns = frameAns.getContentPane(); 
     panelAns.setLayout(null); 

     JLabel l0 = new JLabel(text1+text); 
     b6.append(b7.getText() + "\n" +text1+text+"\n\n"); 
     l0.setBounds(10, 10, 300, 15); 
     panelAns.add(l0); 

     JLabel l01 = new JLabel("________________________________________________"); 
     l01.setBounds(0, 10, 350, 25); 
     panelAns.add(l01); 
     //show the result in a new splash screen 

     JLabel l1 = new JLabel("| USER |"); 
     l1.setBounds(60, 35, 150, 35); 
     panelAns.add(l1); 

     JLabel l2 = new JLabel("| COMPUTER |"); 
     l2.setBounds(165, 35, 150, 35); 
     panelAns.add(l2); 

     JLabel l3 = new JLabel(new ImageIcon(System.getProperty("user.dir")+"/image/"+(humanChoice-1)+".jpg")); 
     l3.setBounds(0, 70, 170, 80); 
     panelAns.add(l3); 

     JLabel l4 = new JLabel(new ImageIcon(System.getProperty("user.dir")+"/image/"+(computerChoice-1)+".jpg")); 
     l4.setBounds(115, 70,170, 80); 
     panelAns.add(l4); 

     JLabel l015 = new JLabel("________________________________________________"); 
     l015.setBounds(0, 10, 350, 280); 
     panelAns.add(l015); 

     JLabel l5 = new JLabel("Win/Loss rate: " + win+"/"+total); 
     l5.setBounds(5, 25, 150, 290); 
     panelAns.add(l5); 

     JLabel l6 = new JLabel("Tie: "+tie); 
     l6.setBounds(5, 30, 125, 310); 
     panelAns.add(l6); 



     quitFrame = new JButton("Quit"); //quit 
     quitFrame.setBackground(Color.DARK_GRAY); 
     quitFrame.setForeground(Color.WHITE); 
     quitFrame.setBounds(210, 165, 80,30); 

     panelAns.add(quitFrame); 

     quitFrame.addActionListener(//quit the game and show three beat up guys 

       new ActionListener() { 
        public void actionPerformed(ActionEvent event) { 
         frameAns.setVisible(false); 
        } 
       }); 

     frameAns.setSize(300, 230); 
     frameAns.getContentPane().setBackground(Color.LIGHT_GRAY); 
     frameAns.setVisible(true); 
     frameAns.setResizable(false); 
     frameAns.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE); 


    } 

    public static int computerRandomChoice(){// creating a random choice of rock paper or scissors by the computer 
     int result=(int)(Math.random()*3)+1;   
     return result; 
    } 

} 

Answer 1

試試這個：

JScrollPane scroll = new JScrollPane(b6); 
scroll.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS); 
panel.add(scroll); 

工作例如：

JFrame frame = new JFrame(); 
JPanel middlePanel = new JPanel(); 
frame.add(middlePanel); 
final JTextArea display = new JTextArea(16, 58); 
display.setEditable(true); // set textArea non-editable 
JScrollPane scroll = new JScrollPane(display); 
scroll.setVerticalScrollBarPolicy(ScrollPaneConstants. 
            VERTICAL_SCROLLBAR_ALWAYS); 

// Add Textarea in to middle panel 
middlePanel.add(scroll);