Java的新手。现在正在学习/学习几周。我们的任务之一是制作一个国际象棋棋盘。目前我有一个名为“ChessBoard”的课程。这是GUI,它有一个创建GUI的方法,然后实例化另一个类的64个实例" ChessSquare" - 构成棋盘的国际象棋方块。我在一个名为" ChessRun"的类中也有一个主方法。它开始了整个事情并实例化了#ChessBoard'。
我的问题是,当点击其中一个ChessSquare实例时,它需要激活ChessBoard中的方法。但是,我一直在找不到符号'在尝试这个时。我知道它没有识别符号,因为它在其他地方被实例化,但我该如何解决这个问题呢?我必须将此方法保留在ChessBoard中。
主要方法:
public class ChessRun{
public static void main(String[] args){
int i = 1;
ChessBoard[] CB = new ChessBoard[2];
CB[i] = new ChessBoard();
CB[i].start();
}
}
ChessBoard Class:
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionListener;
import java.awt.event.*;
import java.awt.event.ActionEvent;
public class ChessBoard{
int clickcount = 0;
int firstsquare;
int secondsquare;
public void Chessboard(){
}
public void start(){
int i = 0;
ChessSquare[] cs = new ChessSquare[64];
JFrame G = new JFrame();
JPanel P = new JPanel();
G.setContentPane(P);
GridLayout grid = new GridLayout(8, 8);
P.setLayout(grid);
G.setTitle("Chess Board");
G.setSize(360, 360);
while (i < 64){
cs[i] = new ChessSquare();
cs[i].setsquarenumber(i);
cs[i].setsize();
cs[i].initialpiece(i);
cs[i].setpiece();
P.add(cs[i]);
i++;
}
G.setVisible(true);
G.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public void beenPressed(int sq){
if(clickcount == 0){
clickcount++;
firstsquare = sq;
}
else if(clickcount == 1){
clickcount++;
secondsquare = sq;
}
else if(clickcount == 2){
}
}
}
ChessSquare类(错误在此类中 - 读取的行:CB1.beenPressed(squarenumber);)
import javax.swing.*;
import javax.swing.JButton;
import java.awt.*;
import java.awt.event.ActionListener;
import java.awt.event.*;
import java.awt.event.ActionEvent;
public class ChessSquare extends JButton implements ActionListener{
private int squarenumber;
private String piece = "emptysquare";
ImageIcon emptysquare = new ImageIcon("EmptySquare.jpg");
ImageIcon selectedsquare = new ImageIcon("SelectedSquare.jpg");
ImageIcon pawn = new ImageIcon("Pawn.jpg");
ImageIcon bishop = new ImageIcon("Bishop.jpg");
ImageIcon rook = new ImageIcon("Rook.jpg");
ImageIcon knight = new ImageIcon("Knight.jpg");
ImageIcon king = new ImageIcon("King.jpg");
ImageIcon queen = new ImageIcon("Queen.jpg");
public ChessSquare(){
addActionListener(this);
}
public void actionPerformed(ActionEvent e){
System.out.println("Pressed");
CB[1].beenPressed(squarenumber);
}
public void setsquarenumber(int i){
this.squarenumber = i;
}
public void initialpiece(int i){
if(47 < i && i < 56){
piece = "pawn";
}
if(i == 56 || i == 63){
piece = "rook";
}
if(i == 57 || i == 62){
piece = "knight";
}
if(i == 58 || i == 61){
piece = "bishop";
}
if(i == 60){
piece = "king";
}
if(i == 59){
piece = "queen";
}
}
public void setsize(){
this.setPreferredSize(new Dimension(44, 44));
}
public String getpiece(){
return piece;
}
public void setpiece(String s){
piece = s;
}
public void setpiece(){
if(piece == "emptysquare"){
this.setempty();
}
if(piece == "pawn"){
this.setpawn();
}
if(piece == "rook"){
this.setrook();
}
if(piece == "knight"){
this.setknight();
}
if(piece == "bishop"){
this.setbishop();
}
if(piece == "queen"){
this.setqueen();
}
if(piece == "king"){
this.setking();
}
}
public void setempty(){
this.setIcon(emptysquare);
}
public void setselected(){
this.setIcon(selectedsquare);
}
public void setpawn(){
this.setIcon(pawn);
}
public void setrook(){
this.setIcon(rook);
}
public void setknight(){
this.setIcon(knight);
}
public void setbishop(){
this.setIcon(bishop);
}
public void setqueen(){
this.setIcon(queen);
}
public void setking(){
this.setIcon(king);
}
}
答案 0 :(得分:2)
CB数组(应该重命名为chessBoards以符合Java命名约定)尚未在ChessSquare类中声明,因此在那里不可见。您需要将数组的引用传递给另一个类,以使其可见。
另外,请勿将字符串与==
或!=
进行比较。这些检查引用相等 - 如果一个对象与另一个引用对象完全相同,那么这不是您感兴趣的内容。请改用equals(...)
方法。
我自己,我有棋盘将ActionListener添加到方块而不是在棋方方面内部添加它。这样广场就不需要董事会的参考。我也会避免扩展JButton。