Question

所以我在这里撕掉我的头发，我似乎无法弄清楚为什么这些JLabel没有画到窗户上。我一直在关注我过去做过的另一个项目，它在JPanel中也使用了JLabel，一切似乎都是正确的。有谁看到我搞砸了这个？

package lab19_20;

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.Random;

public class Lab19_20 extends JFrame implements ActionListener, MouseListener
{


    JLabel[] lblBoard = new JLabel[16];
    int[] nums = {1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8};
    int firstChoice = -1;
    int tries = 0;
    JLabel lblFirst;
    JButton btnGame = new JButton("New Game");
    JLabel lblTries = new JLabel("0");
    JPanel pnlControls = new JPanel();
    JPanel pnlBoard = new JPanel();
    Font lblBoardFont = new Font("Helvetica", Font.BOLD, 30);
    Container content = this.getContentPane();

    public Lab19_20()
    {
        setTitle("The Concentration Game");
        setVisible(true);
        setSize(500, 400);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);


        createLabels();
        content.add(pnlBoard, BorderLayout.NORTH);        
        pnlControls.add(btnGame);
        pnlControls.add(lblTries);
        content.add(pnlControls, BorderLayout.SOUTH);

        btnGame.addActionListener(this);
    }

    void createLabels()
    {
        pnlBoard.setLayout(new GridLayout(4, 4, 5, 5));
        for(int i = 0; i < lblBoard.length; i++)
        {
            lblBoard[i] = new JLabel("", JLabel.CENTER);
            lblBoard[i].setVisible(true);
            lblBoard[i].setOpaque(true);
            lblBoard[i].setBackground(Color.BLUE);
            lblBoard[i].setForeground(Color.BLACK);
            lblBoard[i].setFont(lblBoardFont);
            lblBoard[i].addMouseListener(this);
            lblBoard[i].setName("" + i);
            pnlBoard.add(lblBoard[i]); 
        }
    }

    void shuffle()
    {
        int num1, num2, tmp = 0;
        Random r = new Random();
        for (int i = 0; i < 500; i++)
        {
            num1 = r.nextInt(nums.length);
            num2 = r.nextInt(nums.length);
            tmp = nums[num1];
            nums[num1] = nums[num2];
            nums[num2] = tmp;
        }
    }

    @Override
    public void actionPerformed(ActionEvent ae) 
    {
        shuffle();
        firstChoice = -1;
        for (int i = 0; i < lblBoard.length; i++)
            lblBoard[i].setText("");
        tries = 0;
        lblTries.setText("" + tries);

    }

    @Override
    public void mouseClicked(MouseEvent me) 
    {
        JLabel l = (JLabel) me.getSource();
        int theNumber = Integer.parseInt(l.getName());
        if (firstChoice == -1)
        {
            l.setText("" + nums[theNumber]);
            lblFirst = l;
            firstChoice = theNumber;  
        }
        else if (nums[theNumber] != nums[firstChoice])
        {
            l.setText("" + nums[theNumber]);
            pnlBoard.paintImmediately(0,0, pnlBoard.getWidth(), pnlBoard.getHeight());

            try
            {
                Thread.sleep(250);
            }
            catch(InterruptedException blah){}

            lblFirst.setText("");
            l.setText("");
            lblFirst = null;
            firstChoice = -1;
            tries++;
        }
        else
        {
            l.setText("" + nums[theNumber]);
            firstChoice = -1;
            tries++;
        }

        lblTries.setText("" + tries);

    }  

    public static void main(String[] args) 
    {
        Lab19_20 console = new Lab19_20();
    }

    @Override public void mousePressed(MouseEvent me) {}
    @Override public void mouseReleased(MouseEvent me) {}   
    @Override public void mouseEntered(MouseEvent me) {}   
    @Override public void mouseExited(MouseEvent me) {} 

}

Answer 1

两件快事......

在建立基本用户界面后，最后致电setVisible(true);。
使用lblBoard[i].setText("" + i);代替（或以及lblBoard[i].setName("" + i);

Jpanel中的JLabel数组未显示

1 个答案: