java - JLabel.setText ("__") 在 for 循环中不会打印多次

Question

我将我的 JLabel.setText("__") 放在一个 for 循环中，这样它就可以打印一个单词的长度，用一个 'space' 替换每个字母。这是一个 hangman 游戏，使用空格显示单词的长度。但是它只打印一次。关于为什么的任何提示？此外，如果您有任何关于更好地组织我的代码的提示，我们将不胜感激。提前致谢。

/*PACKAGE DECLARATION*/
package Game;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;


/************************
 * GAME MECHANICS CLASS *
 * **********************/
public class GameStructure {

    /* INSTANCE DECLARATIONS */
    private String []wordList = {"computer","java","activity","alaska","appearance","article",
           "automobile","basket","birthday","canada","central","character","chicken","chosen",
           "cutting","daily","darkness","diagram","disappear","driving","effort","establish","exact",
           "establishment","fifteen","football","foreign","frequently","frighten","function","gradually",
           "hurried","identity","importance","impossible","invented","italian","journey","lincoln",
           "london","massage","minerals","outer","paint","particles","personal","physical","progress",
           "quarter","recognise","replace","rhythm","situation","slightly","steady","stepped",
           "strike","successful","sudden","terrible","traffic","unusual","volume","yesterday"};
    private int []length = new int [64];
    private JTextField tf;//text field instance variable (used)
    private JLabel jl2;//label instance variable (used)
    private JLabel jl3;//label instance (working on)
    private String letter;


    /*****************
     * LENGTH METHOD *
     * ***************/
    public void length(){

        jl3 = new JLabel();

        int j = 0;
        for(j = 0; j<64; j++) {
            length[j] = wordList[j].length();//gets length of words in wordList
        }//end for
        int l = 0;
            for(int m = 0; m<length[l]; m++) {//supposed to print length of word with '__' as each letter
                jl3.setText("__ ");//instead only printing once
                l++;
        }//end for
    }//end length method


    /*****************
     * WINDOW METHOD *
     * ***************/
    public void window() {

    LoadImageApp i = new LoadImageApp();//calling image class

    JFrame gameFrame = new JFrame();//declaration
    JPanel jp = new JPanel();
    JPanel jp2 = new JPanel();//jpanel for blanks
    JLabel jl = new JLabel("Enter a Letter:");//prompt with label

    tf = new JTextField(1);//length of text field by character
    jl2 = new JLabel("Letters Used:    ");

    jp2.add(jl3);
    jp.add(jl);//add label to panel
    jp.add(tf);//add text field to panel
    jp.add(jl2);//add letters used

    gameFrame.add(i); //adds background image to window
    i.add(jp); // adds panel containing label to background image panel
    i.add(jp2);

    gameFrame.setTitle("Hangman");//title of frame window
    gameFrame.setSize(850, 600);//sets size of frame
    gameFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//exit when 'x' button pressed
    gameFrame.setIconImage(new ImageIcon("Hangman-Game-grey.png").getImage());//set the frame icon to an image loaded from a file
    gameFrame.setLocationRelativeTo(null);//window centered
    gameFrame.setResizable(false);//user can not resize window
    gameFrame.setVisible(true);//display frame

  }//end window method


    /*********************
     * USER INPUT METHOD *
     * *******************/
    public void userInput() {

        tf.addActionListener(new ActionListener() {
        @Override
        public void actionPerformed(ActionEvent e) {//when enter key pressed

            JTextField tf = (JTextField)e.getSource();

            letter = tf.getText();
            jl2.setText(jl2.getText() + letter + " ");//sets jlabel text to users entered letter

            }//end actionPerformed method

        });

    }//end userInput method

}//end GameMechanics class

Answer 1

"However it is only printing once. Any tips on why?"

setText 只会设置一次文本。所以你在循环中所做的就是一遍又一遍地设置文本。这是一个建议。在循环中连接字符串，然后设置文本。像这样:

String line = "";
for(int m = 0; m<length[l]; m++) {
    line += "__ ";
    l++;
}
jl3.setText(line);

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" Also, if you have any tips on better organizing my code that would be appreciated. "

尝试 Code Review为此。